High intake of low-fat dairy products enhances weight loss in overweight patients with diabetes who are following isocaloric-restricted diets, according to the results of a study reported in the March issue of Diabetes Care.
"Recent studies suggest that calcium metabolism and perhaps other components of dairy products may contribute to weight reduction in animal and human models," write Danit R. Shahar, RD, PhD, of the Ben-Gurion University of the Negev in Beer-Sheva, Israel, and colleagues. "In addition, an accumulating body of evidence suggests that calcium-rich diets play a direct role in the prevention of obesity."
This was an ancillary study of a 6-month randomized clinical trial evaluating the effect of 3 isocaloric diets in type 2 diabetic patients: mixed-glycemic index carbohydrate diet, low-glycemic index diet, and modified Mediterranean diet. Based on personal choice, intake of low-fat dairy products varied within and across the groups. Dietary consumption, weight, cardiovascular (CVD) risk factors, and diabetes indices were measured at baseline and at 6 months.
The investigators enrolled 259 diabetic patients of average body mass index (BMI) more than 31 kg/m2, and mean age of 55 years. At baseline, there was no difference between the intervention groups in CVD risk factors, diabetes indicators, macronutrient intake, and nutrient intake from dairy products.
Dairy calcium intake was associated with percentage of weight loss. Compared with the lowest tertile of dairy calcium intake, the highest tertile had an odds ratio of 2.4 for weight loss of more than 8% (P = .04), after controlling for nondairy calcium intake, diet type, and the change in energy intake from baseline. Except for triglyceride levels, there was no apparent association between dairy calcium and other health indexes.
"A diet rich in dairy calcium intake enhances weight reduction in type 2 diabetic patients," the authors write. "Such a diet could be tried in diabetic patients, especially those with difficulty adhering to other weight reduction diets."
Study limitations include the fact that it is an ancillary study.
"Before recommending an increase in dairy consumption, it is important to take into consideration the possible negative effect of dairy products on prostate and breast cancer," the authors conclude. "The recommendation of a diet rich in low-fat dairy products seems highly appropriate for weight loss among diabetic patients, in general, and female diabetic patients in particular."
Tnuva Research Institute in Rehovot, Israel, supported this study. The costs of publication of this article were defrayed in part by the payment of page charges, mandating that it must therefore be marked "advertisement" solely to indicate this fact.
Diabetes Care. 2007;30:485-489.
Sunday, August 24, 2008
Monday, August 18, 2008
Extra Calcium May Prevent Hypertension Problems in Pregnant Women
Expectant mothers may be able to prevent potentially serious medical problems in themselves and their babies simply by boosting their daily calcium intake, says a new systematic review. Not only that, but pregnant women at greatest risk for these problems may benefit most from the extra calcium.
The problems are gestational hypertension -- or high blood pressure associated with pregnancy -- and preeclampsia, a medical disorder of pregnant women characterized by high blood pressure and protein in the urine.
If untreated, both conditions can lead to potentially life-threatening medical problems for the mother and complications of preterm birth for the baby, including low birth weight and size, respiratory distress, long-term neurological deficits and even death.
"Pregnant women from communities with low dietary calcium who received at least 1.5 grams of calcium by mouth [daily] during the second half of pregnancy had a lower risk of hypertension and preeclampsia, and of severe complications including death, than women who received placebo treatment," said lead review author Dr. G.J. Hofmeyr.
The results were less dramatic for women with opportunities for better prenatal nutrition: "Women from communities with adequate dietary calcium had a small (10%) reduction in the risk of hypertension, but no significant reduction in the risk of preeclampsia or other adverse outcomes," said Hofmeyr, head of the obstetrics and gynecology department, East London Hospital Complex in South Africa.
The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.
The authors looked at 12 randomized controlled studies, one involving more than 4,000 expectant moms in North America. The most recent and largest of the studies -- conducted by the World Health Organization -- involved more than 8,000 pregnant women internationally.
Preterm birth, or birth before 37 weeks, often stems from high blood pressure and is the leading cause of newborn deaths, particularly in low-income countries. A newly released report from the Institute of Medicine found that 12.5% of U.S. births are preterm and cost society an estimated $26 billion a year.
The Cochrane review found that calcium supplementation during pregnancy is a safe and relatively inexpensive way to reduce the risk of high blood pressure in women more likely to develop it, as well as in women from communities where consumption of dietary calcium is low.
"Calcium supplementation may be of some benefit in reducing the morbidity associated with preeclampsia, and it does no harm," said Dr. John T. Repke, chairman of obstetrics and gynecology at Penn State University College of Medicine.
"There is really almost nothing to lose from trying this approach, and based on this Cochrane Review, potentially something to be gained," added Repke, who has been conducting research on preeclampsia and related disorders for nearly 30 years.
In January 2002, the American College of Obstetricians and Gynecologists issued the following statement: "Daily calcium supplementation has not been shown to prevent preeclampsia and, therefore, is not recommended."
But the review may change the minds -- and clinical recommendations -- of some physicians because it is based on data not available in 2002. "The review is likely to convince health providers of the need to ensure that pregnant women have adequate calcium intake," Hofmeyr said.
Hypertensive disease occurs in approximately 12% to 22% of pregnancies and is directly responsible for 17.6% of maternal deaths in the United States alone, according to ACOG. An estimated 40,000 women around the world die each year due to gestational hypertension and its complications.
Preeclampsia affects an estimated 5% to 6% of first-time moms, and 2% to 3% of them develop severe forms of the disease.
Because preeclampsia is frequently a "silent" disease that may occur without any symptoms, women are encouraged to have their blood pressure checked regularly during pregnancy, even when they feel well, said Hofmeyr. When symptoms do occur, they may include swelling, headache, blurred vision and upper abdominal pain. Severe disease can result in seizures, and the disease is then called "eclampsia."
The exact cause of preeclampsia has yet to be identified. The only cure for the disease is delivery.
The review did not specify how much calcium in pregnancy is enough, but the authors said 1,500 mg per day was effective. They said more research was needed to find out if a lower dose would be effective in preventing gestational hypertension and preeclampsia.
Daily calcium supplements are thought to be safe by most doctors, and many women are already taking calcium as an added preventive safeguard against osteoporosis. One possible side effect associated with daily use of calcium supplements is stones of the kidney and urinary tract, but this remains controversial.
Most pregnant women in the United States are advised by their doctors to take prenatal vitamins daily, but the most common brands contain 500 milligrams of calcium or less, according to Repke.
SOURCE: Health Behavior News Service
The problems are gestational hypertension -- or high blood pressure associated with pregnancy -- and preeclampsia, a medical disorder of pregnant women characterized by high blood pressure and protein in the urine.
If untreated, both conditions can lead to potentially life-threatening medical problems for the mother and complications of preterm birth for the baby, including low birth weight and size, respiratory distress, long-term neurological deficits and even death.
"Pregnant women from communities with low dietary calcium who received at least 1.5 grams of calcium by mouth [daily] during the second half of pregnancy had a lower risk of hypertension and preeclampsia, and of severe complications including death, than women who received placebo treatment," said lead review author Dr. G.J. Hofmeyr.
The results were less dramatic for women with opportunities for better prenatal nutrition: "Women from communities with adequate dietary calcium had a small (10%) reduction in the risk of hypertension, but no significant reduction in the risk of preeclampsia or other adverse outcomes," said Hofmeyr, head of the obstetrics and gynecology department, East London Hospital Complex in South Africa.
The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.
The authors looked at 12 randomized controlled studies, one involving more than 4,000 expectant moms in North America. The most recent and largest of the studies -- conducted by the World Health Organization -- involved more than 8,000 pregnant women internationally.
Preterm birth, or birth before 37 weeks, often stems from high blood pressure and is the leading cause of newborn deaths, particularly in low-income countries. A newly released report from the Institute of Medicine found that 12.5% of U.S. births are preterm and cost society an estimated $26 billion a year.
The Cochrane review found that calcium supplementation during pregnancy is a safe and relatively inexpensive way to reduce the risk of high blood pressure in women more likely to develop it, as well as in women from communities where consumption of dietary calcium is low.
"Calcium supplementation may be of some benefit in reducing the morbidity associated with preeclampsia, and it does no harm," said Dr. John T. Repke, chairman of obstetrics and gynecology at Penn State University College of Medicine.
"There is really almost nothing to lose from trying this approach, and based on this Cochrane Review, potentially something to be gained," added Repke, who has been conducting research on preeclampsia and related disorders for nearly 30 years.
In January 2002, the American College of Obstetricians and Gynecologists issued the following statement: "Daily calcium supplementation has not been shown to prevent preeclampsia and, therefore, is not recommended."
But the review may change the minds -- and clinical recommendations -- of some physicians because it is based on data not available in 2002. "The review is likely to convince health providers of the need to ensure that pregnant women have adequate calcium intake," Hofmeyr said.
Hypertensive disease occurs in approximately 12% to 22% of pregnancies and is directly responsible for 17.6% of maternal deaths in the United States alone, according to ACOG. An estimated 40,000 women around the world die each year due to gestational hypertension and its complications.
Preeclampsia affects an estimated 5% to 6% of first-time moms, and 2% to 3% of them develop severe forms of the disease.
Because preeclampsia is frequently a "silent" disease that may occur without any symptoms, women are encouraged to have their blood pressure checked regularly during pregnancy, even when they feel well, said Hofmeyr. When symptoms do occur, they may include swelling, headache, blurred vision and upper abdominal pain. Severe disease can result in seizures, and the disease is then called "eclampsia."
The exact cause of preeclampsia has yet to be identified. The only cure for the disease is delivery.
The review did not specify how much calcium in pregnancy is enough, but the authors said 1,500 mg per day was effective. They said more research was needed to find out if a lower dose would be effective in preventing gestational hypertension and preeclampsia.
Daily calcium supplements are thought to be safe by most doctors, and many women are already taking calcium as an added preventive safeguard against osteoporosis. One possible side effect associated with daily use of calcium supplements is stones of the kidney and urinary tract, but this remains controversial.
Most pregnant women in the United States are advised by their doctors to take prenatal vitamins daily, but the most common brands contain 500 milligrams of calcium or less, according to Repke.
SOURCE: Health Behavior News Service
Calcium During Pregnancy Could Save Lives
A woman's need for meeting the current recommended levels of calcium just took on new urgency. In today's Journal of the American Medical Association (JAMA), scientists from McMaster University (Ontario, Canada) report that consuming sufficient calcium during pregnancy can reduce the risk of pregnancy- induced hypertension (PIH) and pre-eclampsia, a potentially fatal disorder of high blood pressure and kidney failure. Pregnancy-induced hypertension and pre-eclampsia affect up to one in seven American women and are leading causes of c-sections, pro-term births and low birth-weight babies, making them among the most important issues in pregnancy care.
The most extensive summary of randomized controlled trials in this area to date, McMaster researchers reviewed the data from 14 trials involving nearly 2,500 pregnant women. The compelling results indicate that 1,500 to 2,000 mg daily of calcium supplementation can lower the risk of pregnancy-induced hypertension by 70% and the risk of pre-eclampsia by over 60%!
The analysis could identify no significant side-effects of increased calcium supplementation. The authors also noted that meeting calcium needs during pregnancy should reduce the incidence of related pre-term deliveries, low birth-weight babies and cesarean sections.
Experts Urge Pregnant Women: Get Your Calcium!
This point was supported in an accompanying editorial written by David A.McCarron, M.D., Co-Director of the Calcium Information Center, Co-Head of the Division of Nephrology, Hypertension and Clinical Pharmacology at the University of Dragon Health Sciences University and an accomplished hypertension researcher in his own right. 'There is a calcium crisis in this country," said Dr. McCarron. 'The most recent government survey shows that women of child-bearing age are consuming less than 600 mg of calcium a day, with many getting less than 400! The pre-natal vitamins most doctors prescribe just don't make up the difference -- they contain 200, maybe 300 mg of calcium. The bottom line is that pregnant and lactating women should increase their calcium intake to recommended levels through dietary means whenever possible, by including low-fat dairy products (such as milk, cheese, yogurt), certain dark green vegetables (such as broccoli and kale), and making up the difference by adding a reliable calcium supplement (like TUMS(R)). This simple, yet significant intervention could save thousands of lives and billions of dollars every year if employed by all women of child-bearing ago."
Dr. John Repke, Associate Professor of Obstetrics and Gynecology and Director of the Center for Labor and Birth at Harvard Medical School's Brigham and Women's Hospital in Boston concurred. "Demands of the growing fetus make pregnancy a time of high calcium demand. The mother's calcium intake must increase to protect against any short or long term complications. The McMaster study enhances our understanding of the life-long biological need for calcium and reemphasizes that every pregnant woman should meet the current NIH recommendations of 1,200 to 1,500 mg of calcium per day. I prescribe 2,000 mg of calcium supplementation daily for nearly all my pregnant patients." Dr. Repke also noted that the McMaster findings rest on an extensive body of earlier clinical and basic research which he and colleagues at Harvard and Johns Hopkins, among others, carried out over the past ten years.
BACKGROUND and STATISTICS
Pregnancy Induced Hypertension (PIH) and Pre-eclampsia
* There are 4 million pregnancies per year in the U.S.
* PIH, or high blood pressure, occurs in approximately 15% of all pregnancies.
* Pre-eclampsia occurs in approximately 5% of all pregnancies.
* Pre-eclampsia increases the risk of pre-term births, low birth weight babies and c-section.
* PIH can develop into pre-eclampsia any time, but usually occurs after 20 weeks of gestation.
* PIH occurs more frequently in first time pregnancies, in women over 35, and with twins.
* Women with pre-existing hypertensive disorders or family histories of hypertension are considered at increased risk for PIH and pre-eclampsia.
Society's cost
* The total cost of care for premature infants in this country is $20-$40 billion annually.
* Hospital care for a premature baby averages over $2,000 per day, adding up to as much as $125,000 or more per infants as many premature infants must remain hospitalized for weeks or months.
* Hospital care of a very low birth weight baby can be $7,000 per day, totaling as much as half million dollars per infant!
* Higher birth weight is associated with longer life expectancy and lower life-long risk of hypertension, hyperlipidemia (high cholesterol), heart disease, diabetes and osteoporosis.
* "Higher mortality among U.S. infants is in fact due entirely to a small excess of pre-term deliveries... The prevention of excess mortality among U.S. infants depends on the prevention of pre- term births...- Wilcox, at al; JAMA, March 1, 1995; Vol. 273, No. 9.
The Safety Of Calcium Supplementation
* Calcium supplementation of 1,500 to 2,000 mg daily can lower the risk of PIH by 7O% and the risk of pre-eclampsia by over 60% - Guyati, at al; JAMA, April 10, 1996; Vol. 275, No. 14.
* Adequate calcium during pregnancy is also necessary for protection of the mothers bones and teeth and for development of healthy fetal bones and teeth.
* Studies show no significant negative side-effects of increasing calcium intake during pregnancy, including kidney stones. Daily calcium intakes of up to 2,500 mg have been recognized as safe and do not increase the risk of any adverse health conditions.
* Most pre-natal vitamins contain only 200-300 mg of calcium.
* Chewable calcium is an excellent form of calcium for pregnant women: It Is inexpensive (Tums, for instance, costs less than $60 a year) and offers the added benefit of safe relief of heartburn, which women need during pregnancy.
* Because of it's high quality and superior safety, Tums was chosen by the NIH's division of Child and Human Development as the calcium supplement for the Calcium for Pre-Eclampsia Prevention (CPEP) trial.
Source : http://www.kidsource.com
The most extensive summary of randomized controlled trials in this area to date, McMaster researchers reviewed the data from 14 trials involving nearly 2,500 pregnant women. The compelling results indicate that 1,500 to 2,000 mg daily of calcium supplementation can lower the risk of pregnancy-induced hypertension by 70% and the risk of pre-eclampsia by over 60%!
The analysis could identify no significant side-effects of increased calcium supplementation. The authors also noted that meeting calcium needs during pregnancy should reduce the incidence of related pre-term deliveries, low birth-weight babies and cesarean sections.
Experts Urge Pregnant Women: Get Your Calcium!
This point was supported in an accompanying editorial written by David A.McCarron, M.D., Co-Director of the Calcium Information Center, Co-Head of the Division of Nephrology, Hypertension and Clinical Pharmacology at the University of Dragon Health Sciences University and an accomplished hypertension researcher in his own right. 'There is a calcium crisis in this country," said Dr. McCarron. 'The most recent government survey shows that women of child-bearing age are consuming less than 600 mg of calcium a day, with many getting less than 400! The pre-natal vitamins most doctors prescribe just don't make up the difference -- they contain 200, maybe 300 mg of calcium. The bottom line is that pregnant and lactating women should increase their calcium intake to recommended levels through dietary means whenever possible, by including low-fat dairy products (such as milk, cheese, yogurt), certain dark green vegetables (such as broccoli and kale), and making up the difference by adding a reliable calcium supplement (like TUMS(R)). This simple, yet significant intervention could save thousands of lives and billions of dollars every year if employed by all women of child-bearing ago."
Dr. John Repke, Associate Professor of Obstetrics and Gynecology and Director of the Center for Labor and Birth at Harvard Medical School's Brigham and Women's Hospital in Boston concurred. "Demands of the growing fetus make pregnancy a time of high calcium demand. The mother's calcium intake must increase to protect against any short or long term complications. The McMaster study enhances our understanding of the life-long biological need for calcium and reemphasizes that every pregnant woman should meet the current NIH recommendations of 1,200 to 1,500 mg of calcium per day. I prescribe 2,000 mg of calcium supplementation daily for nearly all my pregnant patients." Dr. Repke also noted that the McMaster findings rest on an extensive body of earlier clinical and basic research which he and colleagues at Harvard and Johns Hopkins, among others, carried out over the past ten years.
BACKGROUND and STATISTICS
Pregnancy Induced Hypertension (PIH) and Pre-eclampsia
* There are 4 million pregnancies per year in the U.S.
* PIH, or high blood pressure, occurs in approximately 15% of all pregnancies.
* Pre-eclampsia occurs in approximately 5% of all pregnancies.
* Pre-eclampsia increases the risk of pre-term births, low birth weight babies and c-section.
* PIH can develop into pre-eclampsia any time, but usually occurs after 20 weeks of gestation.
* PIH occurs more frequently in first time pregnancies, in women over 35, and with twins.
* Women with pre-existing hypertensive disorders or family histories of hypertension are considered at increased risk for PIH and pre-eclampsia.
Society's cost
* The total cost of care for premature infants in this country is $20-$40 billion annually.
* Hospital care for a premature baby averages over $2,000 per day, adding up to as much as $125,000 or more per infants as many premature infants must remain hospitalized for weeks or months.
* Hospital care of a very low birth weight baby can be $7,000 per day, totaling as much as half million dollars per infant!
* Higher birth weight is associated with longer life expectancy and lower life-long risk of hypertension, hyperlipidemia (high cholesterol), heart disease, diabetes and osteoporosis.
* "Higher mortality among U.S. infants is in fact due entirely to a small excess of pre-term deliveries... The prevention of excess mortality among U.S. infants depends on the prevention of pre- term births...- Wilcox, at al; JAMA, March 1, 1995; Vol. 273, No. 9.
The Safety Of Calcium Supplementation
* Calcium supplementation of 1,500 to 2,000 mg daily can lower the risk of PIH by 7O% and the risk of pre-eclampsia by over 60% - Guyati, at al; JAMA, April 10, 1996; Vol. 275, No. 14.
* Adequate calcium during pregnancy is also necessary for protection of the mothers bones and teeth and for development of healthy fetal bones and teeth.
* Studies show no significant negative side-effects of increasing calcium intake during pregnancy, including kidney stones. Daily calcium intakes of up to 2,500 mg have been recognized as safe and do not increase the risk of any adverse health conditions.
* Most pre-natal vitamins contain only 200-300 mg of calcium.
* Chewable calcium is an excellent form of calcium for pregnant women: It Is inexpensive (Tums, for instance, costs less than $60 a year) and offers the added benefit of safe relief of heartburn, which women need during pregnancy.
* Because of it's high quality and superior safety, Tums was chosen by the NIH's division of Child and Human Development as the calcium supplement for the Calcium for Pre-Eclampsia Prevention (CPEP) trial.
Source : http://www.kidsource.com
Calcium could reduce severity of preeclampsia in pregnant women
A new international level study has found that consuming enough amounts of calcium during pregnancy could help stave off a lethal condition called as preeclampsia, in which the blood pressure levels of the pregnant woman shoot up to dangerous levels.
But Dr. Jose Villar of the World Health Organization, who led this study, admitted that the extra calcium did not seem to reduce the number of women who suffered from this condition, but only reduced its severity. "Women under 20 are at particular risk of these complications and would benefit from consuming more calcium. All women should be sure that they have at least 1.2g of calcium during pregnancy," he said.
Reporting in the March issue of the American Journal of Obstetrics and Gynecology, the research team spread across the globe tracked the progress of 8300 women selected for the study. All these women had a low intake of dietary calcium to the tune of 600 milligrams a day. The women were randomly divided into two groups based on similar ages, demographic characteristics and blood pressure levels. One group was given 1.5 grams of calcium, while the other group received a placebo.
It was found that although calcium supplements did not significantly alter the incidence of preeclampsia, they did reduce the severity of it. Additionally, it was found that the high blood pressure was also controlled in the calcium group. These trials were held at centers of the WHO Maternal and Perinatal Research Network at "Rosario, Argentina; Assiut, Egypt; Nagpur and Vellore, India; Lima, Peru; East London and Johannesburg, South Africa; and Ho Chi Minh City, Vietnam."
But Dr. Marshall Lindheimer of the University of Chicago and a co-author of the report said they were disappointed since there was no conclusive evidence linking calcium intake to reduced incidence of preeclampsia. The exact mechanism of how calcium helped in preeclampsia was also not clear.
"It may affect the contractability of the blood vessels," he said. "Intracellular calcium is very important in muscle physiology. When you replenish the calcium, they [vessels] are in a more dilated state. It may be that effect which makes the disease less severe."
Preeclampsia affects about 9 percent of all pregnancies in the world with most cases being reported outside the United States where calcium deficiency is more marked. In extreme cases of preeclampsia, the woman can become affected by seizures, go into a coma or even die. It is recommended that pregnant women up their calcium intake to 1,200 milligrams per day through diet or supplements.
Refference : Darya Zarin (http://www.earthtimes.org)
But Dr. Jose Villar of the World Health Organization, who led this study, admitted that the extra calcium did not seem to reduce the number of women who suffered from this condition, but only reduced its severity. "Women under 20 are at particular risk of these complications and would benefit from consuming more calcium. All women should be sure that they have at least 1.2g of calcium during pregnancy," he said.
Reporting in the March issue of the American Journal of Obstetrics and Gynecology, the research team spread across the globe tracked the progress of 8300 women selected for the study. All these women had a low intake of dietary calcium to the tune of 600 milligrams a day. The women were randomly divided into two groups based on similar ages, demographic characteristics and blood pressure levels. One group was given 1.5 grams of calcium, while the other group received a placebo.
It was found that although calcium supplements did not significantly alter the incidence of preeclampsia, they did reduce the severity of it. Additionally, it was found that the high blood pressure was also controlled in the calcium group. These trials were held at centers of the WHO Maternal and Perinatal Research Network at "Rosario, Argentina; Assiut, Egypt; Nagpur and Vellore, India; Lima, Peru; East London and Johannesburg, South Africa; and Ho Chi Minh City, Vietnam."
But Dr. Marshall Lindheimer of the University of Chicago and a co-author of the report said they were disappointed since there was no conclusive evidence linking calcium intake to reduced incidence of preeclampsia. The exact mechanism of how calcium helped in preeclampsia was also not clear.
"It may affect the contractability of the blood vessels," he said. "Intracellular calcium is very important in muscle physiology. When you replenish the calcium, they [vessels] are in a more dilated state. It may be that effect which makes the disease less severe."
Preeclampsia affects about 9 percent of all pregnancies in the world with most cases being reported outside the United States where calcium deficiency is more marked. In extreme cases of preeclampsia, the woman can become affected by seizures, go into a coma or even die. It is recommended that pregnant women up their calcium intake to 1,200 milligrams per day through diet or supplements.
Refference : Darya Zarin (http://www.earthtimes.org)
Extra Calcium May Prevent Hypertension Problems in Pregnant Women
By Joel R. Cooper, Contributing Writer
Health Behavior News Service
Expectant mothers may be able to prevent potentially serious medical problems in themselves and their babies simply by boosting their daily calcium intake, says a new systematic review. Not only that, but pregnant women at greatest risk for these problems may benefit most from the extra calcium.
The problems are gestational hypertension — or high blood pressure associated with pregnancy — and preeclampsia, a medical disorder of pregnant women characterized by high blood pressure and protein in the urine.
If untreated, both conditions can lead to potentially life-threatening medical problems for the mother and complications of preterm birth for the baby, including low birth weight and size, respiratory distress, long-term neurological deficits and even death.
“Pregnant women from communities with low dietary calcium who received at least 1.5 grams of calcium by mouth [daily] during the second half of pregnancy had a lower risk of hypertension and preeclampsia, and of severe complications including death, than women who received placebo treatment,” said lead review author Dr. G.J. Hofmeyr.
The results were less dramatic for women with opportunities for better prenatal nutrition: “Women from communities with adequate dietary calcium had a small (10 percent) reduction in the risk of hypertension, but no significant reduction in the risk of preeclampsia or other adverse outcomes,” said Hofmeyr, head of the obstetrics and gynecology department, East London Hospital Complex in South Africa.
The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.
The authors looked at 12 randomized controlled studies, one involving more than 4,000 expectant moms in North America. The most recent and largest of the studies — conducted by the World Health Organization — involved more than 8,000 pregnant women internationally.
Preterm birth, or birth before 37 weeks, often stems from high blood pressure and is the leading cause of newborn deaths, particularly in low-income countries. A newly released report from the Institute of Medicine found that 12.5 percent of U.S. births are preterm and cost society an estimated $26 billion a year.
The Cochrane review found that calcium supplementation during pregnancy is a safe and relatively inexpensive way to reduce the risk of high blood pressure in women more likely to develop it, as well as in women from communities where consumption of dietary calcium is low.
“Calcium supplementation may be of some benefit in reducing the morbidity associated with preeclampsia, and it does no harm,” said Dr. John T. Repke, chairman of obstetrics and gynecology at Penn State University College of Medicine.
“There is really almost nothing to lose from trying this approach, and based on this Cochrane Review, potentially something to be gained,” added Repke, who has been conducting research on preeclampsia and related disorders for nearly 30 years.
In January 2002, the American College of Obstetricians and Gynecologists issued the following statement: “Daily calcium supplementation has not been shown to prevent preeclampsia and, therefore, is not recommended.”
But the review may change the minds — and clinical recommendations — of some physicians because it is based on data not available in 2002. “The review is likely to convince health providers of the need to ensure that pregnant women have adequate calcium intake,” Hofmeyr said.
Hypertensive disease occurs in approximately 12 percent to 22 percent of pregnancies and is directly responsible for 17.6 percent of maternal deaths in the United States alone, according to ACOG. An estimated 40,000 women around the world die each year due to gestational hypertension and its complications.
Preeclampsia affects an estimated 5 percent to 6 percent of first-time moms, and 2 percent to 3 percent of them develop severe forms of the disease.
Because preeclampsia is frequently a “silent” disease that may occur without any symptoms, women are encouraged to have their blood pressure checked regularly during pregnancy, even when they feel well, said Hofmeyr. When symptoms do occur, they may include swelling, headache, blurred vision and upper abdominal pain. Severe disease can result in seizures, and the disease is then called “eclampsia.”
The exact cause of preeclampsia has yet to be identified. The only cure for the disease is delivery.
The review did not specify how much calcium in pregnancy is enough, but the authors said 1.5 grams (or 1,500 milligrams) per day was effective. They said more research was needed to find out if a lower dose would be effective in preventing gestational hypertension and preeclampsia.
Daily calcium supplements are thought to be safe by most doctors, and many women are already taking calcium as an added preventive safeguard against osteoporosis. One possible side effect associated with daily use of calcium supplements is stones of the kidney and urinary tract, but this remains controversial. Most pregnant women in the United States are advised by their doctors to take prenatal vitamins daily, but the most common brands contain 500 milligrams of calcium or less, according to Repke.
Health Behavior News Service
Expectant mothers may be able to prevent potentially serious medical problems in themselves and their babies simply by boosting their daily calcium intake, says a new systematic review. Not only that, but pregnant women at greatest risk for these problems may benefit most from the extra calcium.
The problems are gestational hypertension — or high blood pressure associated with pregnancy — and preeclampsia, a medical disorder of pregnant women characterized by high blood pressure and protein in the urine.
If untreated, both conditions can lead to potentially life-threatening medical problems for the mother and complications of preterm birth for the baby, including low birth weight and size, respiratory distress, long-term neurological deficits and even death.
“Pregnant women from communities with low dietary calcium who received at least 1.5 grams of calcium by mouth [daily] during the second half of pregnancy had a lower risk of hypertension and preeclampsia, and of severe complications including death, than women who received placebo treatment,” said lead review author Dr. G.J. Hofmeyr.
The results were less dramatic for women with opportunities for better prenatal nutrition: “Women from communities with adequate dietary calcium had a small (10 percent) reduction in the risk of hypertension, but no significant reduction in the risk of preeclampsia or other adverse outcomes,” said Hofmeyr, head of the obstetrics and gynecology department, East London Hospital Complex in South Africa.
The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.
The authors looked at 12 randomized controlled studies, one involving more than 4,000 expectant moms in North America. The most recent and largest of the studies — conducted by the World Health Organization — involved more than 8,000 pregnant women internationally.
Preterm birth, or birth before 37 weeks, often stems from high blood pressure and is the leading cause of newborn deaths, particularly in low-income countries. A newly released report from the Institute of Medicine found that 12.5 percent of U.S. births are preterm and cost society an estimated $26 billion a year.
The Cochrane review found that calcium supplementation during pregnancy is a safe and relatively inexpensive way to reduce the risk of high blood pressure in women more likely to develop it, as well as in women from communities where consumption of dietary calcium is low.
“Calcium supplementation may be of some benefit in reducing the morbidity associated with preeclampsia, and it does no harm,” said Dr. John T. Repke, chairman of obstetrics and gynecology at Penn State University College of Medicine.
“There is really almost nothing to lose from trying this approach, and based on this Cochrane Review, potentially something to be gained,” added Repke, who has been conducting research on preeclampsia and related disorders for nearly 30 years.
In January 2002, the American College of Obstetricians and Gynecologists issued the following statement: “Daily calcium supplementation has not been shown to prevent preeclampsia and, therefore, is not recommended.”
But the review may change the minds — and clinical recommendations — of some physicians because it is based on data not available in 2002. “The review is likely to convince health providers of the need to ensure that pregnant women have adequate calcium intake,” Hofmeyr said.
Hypertensive disease occurs in approximately 12 percent to 22 percent of pregnancies and is directly responsible for 17.6 percent of maternal deaths in the United States alone, according to ACOG. An estimated 40,000 women around the world die each year due to gestational hypertension and its complications.
Preeclampsia affects an estimated 5 percent to 6 percent of first-time moms, and 2 percent to 3 percent of them develop severe forms of the disease.
Because preeclampsia is frequently a “silent” disease that may occur without any symptoms, women are encouraged to have their blood pressure checked regularly during pregnancy, even when they feel well, said Hofmeyr. When symptoms do occur, they may include swelling, headache, blurred vision and upper abdominal pain. Severe disease can result in seizures, and the disease is then called “eclampsia.”
The exact cause of preeclampsia has yet to be identified. The only cure for the disease is delivery.
The review did not specify how much calcium in pregnancy is enough, but the authors said 1.5 grams (or 1,500 milligrams) per day was effective. They said more research was needed to find out if a lower dose would be effective in preventing gestational hypertension and preeclampsia.
Daily calcium supplements are thought to be safe by most doctors, and many women are already taking calcium as an added preventive safeguard against osteoporosis. One possible side effect associated with daily use of calcium supplements is stones of the kidney and urinary tract, but this remains controversial. Most pregnant women in the United States are advised by their doctors to take prenatal vitamins daily, but the most common brands contain 500 milligrams of calcium or less, according to Repke.
Pregnant Women With Calcium Deficiency Release Lead Faster From Bones
Pregnant women who don't consume enough calcium in their diets or through supplements show greater increases in lead in their bloodstreams than pregnant women with normal calcium levels, according to a new University of North Carolina at Chapel Hill study.
Bone tissue contains 95% of the body's lead. In pregnant women who get less calcium, the bone tissue turns over, or "demineralizes," more rapidly than bone in other pregnant women and releases locked-up lead into the blood, researchers found.
Lead emerges from bone during the second half of pregnancy and might hurt both mothers and their babies, their work showed. The study, which was published in the November issue of the Journal of Epidemiology, also offers new evidence that calcium consumption can minimize bone demineralization in pregnant women.
"Past research has linked lead to many adverse conditions, including nervous system and possible cardiovascular problems," said Dr. Irva Hertz-Picciotto, professor of epidemiology at the University of North Carolina–Chapel Hill School of Public Health and lead author. "In this study, in which lead levels were very low overall, we saw that the same characteristics that predict greater lead at high exposures also predict a greater lead level even at a much lower range. That means there may be virtually no 'natural' background of blood lead for which man-made sources can't be identified."
The study involved 195 women who entered prenatal care at Magee-Women's Hospital in Pittsburgh between 1992 and 1995. Using a technique called atomic absorption spectrophotometry, researchers analyzed up to 5 blood samples from each woman for lead during her pregnancy and took extensive patient histories.
"We found not only that calcium intake at the recommended daily allowance level protected somewhat against lead, but also that higher calcium levels corresponded with even less lead," Hertz-Picciotto said. "The protective effect of calcium became stronger as pregnancy progressed."
The variables that correspond with more lead include smoking, less education, being black, and low calcium intake, she said. Variables associated with a reduced lead level include history of breast-feeding and higher calcium intake. "We are still trying to determine whether there are health effects from these low levels," Hertz-Picciotto said.
The blood lead levels of older mothers increased more during pregnancy compared with younger mothers. The researchers suggested that was because older mothers had accumulated more lead in their bones, particularly in the 1960s and 1970s when leaded gasoline was still used in automobiles.
Age and calcium had combined effects. From week 20 to week 40, for example, blood lead levels in pregnant women with low calcium intakes increased 25% for patients aged 18 years, 37% for patients aged 23 years, 65% for patients aged 33 years, and 99% at age 43, she said.
Pregnancy and the first 4 years after menopause are periods when women's bones are most likely to undergo turnover, including demineralization, the scientist said.
The new findings mirror those of a study published in 1994 of about 200 women in Mexico City whose blood lead levels were significantly higher because of pollution and greater exposure on average to lead at work and home.
Source: http://www.medscape.com/viewarticle/412237
Bone tissue contains 95% of the body's lead. In pregnant women who get less calcium, the bone tissue turns over, or "demineralizes," more rapidly than bone in other pregnant women and releases locked-up lead into the blood, researchers found.
Lead emerges from bone during the second half of pregnancy and might hurt both mothers and their babies, their work showed. The study, which was published in the November issue of the Journal of Epidemiology, also offers new evidence that calcium consumption can minimize bone demineralization in pregnant women.
"Past research has linked lead to many adverse conditions, including nervous system and possible cardiovascular problems," said Dr. Irva Hertz-Picciotto, professor of epidemiology at the University of North Carolina–Chapel Hill School of Public Health and lead author. "In this study, in which lead levels were very low overall, we saw that the same characteristics that predict greater lead at high exposures also predict a greater lead level even at a much lower range. That means there may be virtually no 'natural' background of blood lead for which man-made sources can't be identified."
The study involved 195 women who entered prenatal care at Magee-Women's Hospital in Pittsburgh between 1992 and 1995. Using a technique called atomic absorption spectrophotometry, researchers analyzed up to 5 blood samples from each woman for lead during her pregnancy and took extensive patient histories.
"We found not only that calcium intake at the recommended daily allowance level protected somewhat against lead, but also that higher calcium levels corresponded with even less lead," Hertz-Picciotto said. "The protective effect of calcium became stronger as pregnancy progressed."
The variables that correspond with more lead include smoking, less education, being black, and low calcium intake, she said. Variables associated with a reduced lead level include history of breast-feeding and higher calcium intake. "We are still trying to determine whether there are health effects from these low levels," Hertz-Picciotto said.
The blood lead levels of older mothers increased more during pregnancy compared with younger mothers. The researchers suggested that was because older mothers had accumulated more lead in their bones, particularly in the 1960s and 1970s when leaded gasoline was still used in automobiles.
Age and calcium had combined effects. From week 20 to week 40, for example, blood lead levels in pregnant women with low calcium intakes increased 25% for patients aged 18 years, 37% for patients aged 23 years, 65% for patients aged 33 years, and 99% at age 43, she said.
Pregnancy and the first 4 years after menopause are periods when women's bones are most likely to undergo turnover, including demineralization, the scientist said.
The new findings mirror those of a study published in 1994 of about 200 women in Mexico City whose blood lead levels were significantly higher because of pollution and greater exposure on average to lead at work and home.
Source: http://www.medscape.com/viewarticle/412237
Low Calcium May Equal High Lead Levels in Pregnant Women
Most pregnant women pay close attention to nutrition. But one thing they may not be aware of is the link between calcium intake and lead. New research suggests that not getting enough calcium during this critical time can drive up levels of lead in the blood, which could be harmful to a developing baby.
Lead in a mother's blood may affect the development of various organs of the fetus, including the brain. In children, lead exposure has been linked to learning and intelligence problems.
During pregnancy, when the body's demand for calcium is high, not getting enough of the crucial mineral speeds up the production of new bone to replace old, dying bone. Because nearly all of the body's lead is stored away in bone, the lead "leaks" into the bloodstream when the bone turns over. It's a process that calcium can help prevent.
A study in the November issue of the American Journal of Epidemiology finds that women with the lowest levels of calcium -- gotten from either food or supplements -- also had the highest levels of lead in the blood. Although the study did not show any direct health impact on the fetus, the researchers say it's reasonable to assume that any amount of lead in the body would be potentially dangerous.
The study involved almost 200 pregnant women who had their blood drawn and tested for lead up to five times during their pregnancy. The women also reported on the amount of calcium in their diet from foods including milk, yogurt, cheese, ice cream, eggs, pizza, and fish.
"Definitely, the women who were getting very little calcium were at risk for higher blood lead levels," says lead author Irva Hertz-Picciotto, MD, of the University of North Carolina at Chapel Hill. She says most of the women in the study reported getting the bulk of their daily calcium from milk and cheese pizza. Other common sources included vitamins and antacids.
In addition, black women had lower calcium intake and higher blood lead levels than white women, and smokers had lower calcium and higher lead than nonsmokers.
Hertz-Picciotto says the study suggests that women need to be getting above and beyond the recommended daily allowance of calcium during pregnancy to avoid rising lead levels. She says pregnant women should aim for a minimum of 2,000 mg of calcium per day, which is about 800 mg higher than current government recommendations.
Furthermore, women who get little calcium early in pregnancy may benefit from calcium supplements in addition to bulking up their diet with extra glasses of milk and other calcium-rich foods.
In the study, lead increased with each trimester due to the increasing demands on the body for calcium during pregnancy. Lead levels also increased with age.
A researcher who studies lead tells WebMD that the study is a practical reminder for women to pay particular attention to calcium when they're pregnant and make sure that they are meeting -- and exceeding -- the recommended amounts.
In addition, Howard Hu, MD, MPH, ScD, says women who think they have had lead exposures from work or other environmental sources like lead paint should consider seeing a specialist and have their blood lead levels tested.
But Hu, an associate professor of occupational medicine at the Harvard School of Public Health in Boston, says that much more research is needed to determine how much of a problem low calcium and increased lead in the blood may be. To answer that question, his research group is planning to give calcium supplements to pregnant women to see if it makes a difference in their blood lead levels.
source: This article is from the WebMD
Lead in a mother's blood may affect the development of various organs of the fetus, including the brain. In children, lead exposure has been linked to learning and intelligence problems.
During pregnancy, when the body's demand for calcium is high, not getting enough of the crucial mineral speeds up the production of new bone to replace old, dying bone. Because nearly all of the body's lead is stored away in bone, the lead "leaks" into the bloodstream when the bone turns over. It's a process that calcium can help prevent.
A study in the November issue of the American Journal of Epidemiology finds that women with the lowest levels of calcium -- gotten from either food or supplements -- also had the highest levels of lead in the blood. Although the study did not show any direct health impact on the fetus, the researchers say it's reasonable to assume that any amount of lead in the body would be potentially dangerous.
The study involved almost 200 pregnant women who had their blood drawn and tested for lead up to five times during their pregnancy. The women also reported on the amount of calcium in their diet from foods including milk, yogurt, cheese, ice cream, eggs, pizza, and fish.
"Definitely, the women who were getting very little calcium were at risk for higher blood lead levels," says lead author Irva Hertz-Picciotto, MD, of the University of North Carolina at Chapel Hill. She says most of the women in the study reported getting the bulk of their daily calcium from milk and cheese pizza. Other common sources included vitamins and antacids.
In addition, black women had lower calcium intake and higher blood lead levels than white women, and smokers had lower calcium and higher lead than nonsmokers.
Hertz-Picciotto says the study suggests that women need to be getting above and beyond the recommended daily allowance of calcium during pregnancy to avoid rising lead levels. She says pregnant women should aim for a minimum of 2,000 mg of calcium per day, which is about 800 mg higher than current government recommendations.
Furthermore, women who get little calcium early in pregnancy may benefit from calcium supplements in addition to bulking up their diet with extra glasses of milk and other calcium-rich foods.
In the study, lead increased with each trimester due to the increasing demands on the body for calcium during pregnancy. Lead levels also increased with age.
A researcher who studies lead tells WebMD that the study is a practical reminder for women to pay particular attention to calcium when they're pregnant and make sure that they are meeting -- and exceeding -- the recommended amounts.
In addition, Howard Hu, MD, MPH, ScD, says women who think they have had lead exposures from work or other environmental sources like lead paint should consider seeing a specialist and have their blood lead levels tested.
But Hu, an associate professor of occupational medicine at the Harvard School of Public Health in Boston, says that much more research is needed to determine how much of a problem low calcium and increased lead in the blood may be. To answer that question, his research group is planning to give calcium supplements to pregnant women to see if it makes a difference in their blood lead levels.
source: This article is from the WebMD
Subscribe to:
Posts (Atom)
Posts
