EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, April 26, 2004
To contact Gary C. Curhan, M.D., Sc.D., call Amy Dayton at 617/534-1600.

DIETARY CALCIUM ASSOCIATED WITH REDUCED RISK OF KIDNEY STONES IN YOUNGER WOMEN

CHICAGO—Including more calcium in the diet may help to reduce the risk of kidney stone formation in younger women, according to an article in the April 26 issue of the Archives of Internal Medicine, one of the JAMA/Archives journals.

According to information in the article, diet plays an important role in the development of kidney stones. In older men and women, higher levels of dietary calcium, sodium, animal protein, and sucrose (sugar) may be associated with a reduced risk of developing kidney stones, the article states. A compound called phytate (found in plants and cereal grains) may also play a role and might inhibit the formation of kidney stones by preventing tiny crystals of calcium oxalate (which is a component of kidney stones) from forming.

Gary C. Curhan, M.D., Sc.D., of Brigham and Women's Hospital, Boston, and colleagues examined the association between diet and risk of developing kidney stones among 96,245 female participants aged 27 to 44 years in the Nurses' Health Study II. Participants had no history of kidney stones and completed questionnaires on types and quantities of foods they ate in 1991 and 1995.

The researchers documented 1,223 new kidney stones over the eight years of the study. They found that higher dietary calcium was associated with a reduced risk of kidney stones. Women who consumed the most calcium (top 20 percent of calcium intake) had a 27 percent lower risk of developing kidney stones compared to women who reported consuming the least amount of calcium (lowest 20 percent of calcium intake). Calcium supplement use was not associated with risk of kidney stone formation. The researchers found that phytate consumption was also associated with a reduced risk of stone formation. Women who consumed the most phytate (top 20 percent of phytate intake) in the study group had a 37 percent lower risk of developing kidney stones compared to women who consumed the least amount of phytate (lowest 20 percent of phytate intake).

"In summary, our findings indicate that a higher intake of dietary calcium decreases the risk of kidney stone formation in younger women," the authors write. "The lack of an increased risk with greater intake of calcium and the potential to increase the risk with calcium restriction reinforce that the routine restriction of dietary calcium in patients who have had a kidney stone is no longer justified."

EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, April 26, 2004
To contact Ian R. Reid. M.D., e-mail:i.reid{at}auckland.ac.nz .

RESEARCHERS COMPARE DRUGS USED TO PREVENT OSTEOPOROSIS

CHICAGO—Raloxifene, a drug used to prevent osteoporosis in postmenopausal women, and conjugated equine estrogen (CEE, a hormone therapy) help increase bone density, although CEE seems to be more effective, according to an article in the April 26 issue of the Archives of Internal Medicine, one of the JAMA/Archives journals.

According to information in the article, raloxifene helps prevent bone loss and increases bone mineral density, and CEE has also been used to help prevent osteoporosis. However, there is little information comparing the two drugs.

Ian R. Reid, M.D., of The University of Auckland, New Zealand, and colleagues compared the effects of CEE and different dosages of raloxifene on bone mineral density in 619 postmenopausal women (average age, 53 years) with prior hysterectomy at 38 medical centers in Europe, North America, Australasia and South Africa.

In this randomized, placebo-controlled trial, women were randomly assigned to take either 60 milligrams per day of raloxifene, 150 milligrams per day of raloxifene, 0.625 milligrams per day of CEE, or placebo. Bone mineral density was measured in the spine and in the femur (a large bone in the leg). The study lasted three years.

The researchers found that bone density declined by two percent in the placebo group, was stable in the two raloxifene groups, and increased by 4.6 percent in the CEE group. At three years, total cholesterol levels were not different compared to the beginning of the study for the placebo group and the CEE group, however, triglyceride concentrations (certain types of fats in the blood) increased by 24.6 percent in the CEE group at three years, a significantly greater change than in the raloxifene groups, which were 4.9 percent and 8.0 percent above levels at the beginning of the study. The researchers also found that raloxifene did not affect high-density lipoprotein (HDL) cholesterol (the "good" cholesterol), but CEE increased it by 13.4 percent compared with placebo.

"Raloxifene and CEE have beneficial effects on bone density and bone turnover, although effects of CEE are more marked," write the researchers.

EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, April 26, 2004
To contact Ira S. Ockene, M.D., call Michael Cohen at 508/856-2000.

CHOLESTEROL LEVELS FLUCTUATE WITH THE SEASONS

CHICAGO—Cholesterol levels vary with the seasons, reaching their highest levels in the winter months, according to an article in the April 26 issue of the Archives of Internal Medicine, one of the JAMA/Archives journals.

According to the article, a variety of studies have suggested that cholesterol levels are higher in the fall and winter than they are in the spring and summer. Although the mechanism for this phenomenon is not clear, such variation could result in larger numbers of people being diagnosed as having high cholesterol in the winter, the article states.

Ira S. Ockene, M.D., of the University of Massachusetts Medical Center, Worcester, and colleagues investigated the seasonal variation in cholesterol among 517 healthy volunteers from a health maintenance organization serving central Massachusetts. Data were collected quarterly over a twelve-month period on diet, physical activity, exposure to light, general behavioral information, and cholesterol levels were also measured.

The researchers found that the average cholesterol level was 222 mg/dL (milligrams per deciliter of blood) in men and 213 mg/dL in women. According to the U.S. National Cholesterol Education Program guidelines, 240 mg/dL is the threshold level for hyperlipidemia (high cholesterol). Cholesterol levels were increased by 3.9 mg/dL in men, with a peak in December, and by 5.4 mg/dL in women, with a peak in January. The researchers found that the increases were greater in participants who had high cholesterol levels to begin with. Overall, 22 percent more participants had total cholesterol levels of 240 mg/dL or greater (high cholesterol) in the winter than in the summer. The researchers write that seasonal changes in plasma volume (a component of blood) explained a substantial proportion of the observed increase in cholesterol levels in the winter. The authors also report that there were no statistically significant seasonal changes in dietary and caloric intake.

"In conclusion, this study demonstrates seasonal variation in blood lipid levels, with a peak in the winter and a trough in the summer. Our findings suggest that there is greater amplitude in seasonal variability in women and in people with hypercholesterolemia [high cholesterol]," the authors write. "However, changes in relative plasma volume seem to explain a substantial proportion of the observed seasonal difference in blood lipid levels. Changes in temperature and/or physical activity in winter and summer seem to be related to concomitant changes in relative plasma volume."

EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, April 26, 2004
To contact Anne M. McCaffrey, M.D., call John Lacey at 617/432-0442.

MANY AMERICANS USE PRAYER FOR HEALTH CONCERNS

CHICAGO—An estimated one-third of adults use prayer, in addition to conventional medical care and complementary and alternative therapies, for health concerns, according to an article in the April 26 issue of the Archives of Internal Medicine, one of the JAMA/Archives journals.

According to information in the article, many Americans believe in the healing power of prayer. While there is no proven therapeutic efficacy of prayer, associations between spirituality and better health outcomes have been described, the article states.

Anne M. McCaffrey, M.D., of Harvard Medical School, Boston, and colleagues investigated the prevalence and patterns of the use of prayer for health concerns.

The researchers conducted a national survey of 2,055 people (age 18 or older) between October 1997 and February 1998 on the use of prayer. Data were also collected on sociodemographics, use of conventional medicine, and use of complementary and alternative medical therapies.

The researchers found that 35 percent of respondents used prayer for health concerns, and that 75 percent of these people prayed for wellness, and 22 percent prayed for specific medical conditions. Of those praying for specific medical conditions, 69 percent found prayer very helpful. Participants who were older than 33 years, female, attained an education beyond high school, had depression, chronic headaches, back and/or neck pain, digestive problems or allergies were all more likely to use prayer.