Field Notes

High-Dose Vitamin D Linked With Increased Fracture Risk Among Older Women

Women aged 70 and older who received a single annual high dose of vitamin D experienced a higher rate of falls and fractures compared with women who received a placebo, according to a study in The Journal of the American Medical Association.

The results of studies investigating the effects of cholecalciferol (vitamin D) supplementation on falls and fractures have been inconsistent, with some meta-analyses indicating a reduced fracture risk, while others have concluded that vitamin D supplementation is ineffective or may increase the risk of fracture. For individuals attempting to modify their risk of falls or fractures via vitamin D, adherence to daily supplementation is typically poor, according to the article.

Kerrie M. Sanders, PhD, of the University of Melbourne in Australia, and colleagues conducted a study to examine whether high-dose cholecalciferol (500,000 IU) given orally once per year to older women would reduce falls and fractures. The vitamin D was given in a single, high dose to address low adherence and to be a practical intervention easily translated to clinical practice. The trial included 2,256 community-dwelling women aged 70 and older considered to be at high risk of fracture who were recruited from June 2003 to June 2005 and were randomly assigned to receive 500,000 IU of cholecalciferol or placebo each autumn to winter for three to five years.

The trial participants had a total of 5,404 falls over the study period, with 74% of 837 women in the vitamin D group and 68% of 769 women in the placebo group having at least one fall. Analysis indicated that women in the annual high-dose vitamin D group experienced 15% more falls. Women in the vitamin D group had 171 fractures vs. 135 in the placebo group, with 26% more fractures for participants in the vitamin D group, who also had a 31% higher incidence of falls in the first three months following dosing.

“This is the first study to demonstrate increased risk of falls associated with any vitamin D intervention and the second study to demonstrate an increased fracture risk associated with annual high-dose vitamin D therapy in elderly women. Our study used the largest total annual dose of vitamin D (500,000 IU) reported in any large randomized controlled trial, raising the possibility that the adverse outcome is dose-related. The opposing outcomes of 2 studies that used the same total annual dose (300,000 IU intramuscularly) suggest that the dosing regimen (ie, 4 monthly vs. annually) rather than the total dose might determine the outcome,” the authors wrote.

— Source: American Medical Association

 

China Faces Public Health Crisis With Projected Increase in Cardiovascular Disease by 2030

Annual heart disease and stroke rates in China will rise by up to 73% by 2030, given an aging population and other increased risk factors, without policies and prevention efforts aimed at controlling blood pressure and smoking, according to research from Columbia University Medical Center published in Circulation: Cardiovascular Quality and Outcomes.

“China’s standard of living and life expectancy have improved for many, but aging, dietary changes, and reduced physical activity are leading to more heart disease and stroke,” says lead author Andrew Moran, MD, MPH, an assistant professor of medicine at Columbia University Medical Center and an attending physician in general internal medicine at NewYork-Presbysterian Hospital. “Our study used a computer model to forecast future cardiovascular disease [CVD] in Chinese adults and is the first to project the individual and combined effects of major risk factor trends on a national scale.”

Moran and colleagues reviewed risk-factor surveys of Chinese adults aged 35 to 84 since economic reforms in the 1980s and used them to project future trends in blood pressure, cholesterol, smoking, diabetes, and body weight. Although smoking prevalence has declined in men by more than 10% since the mid-1980s, 62% of Chinese men still smoke and 49% of nonsmokers, mostly women, are exposed to passive smoke, researchers say.

Moran and his colleagues projected that annual rates of CVD in China will increase by more than 50% due to aging and population growth alone between 2010 and 2030. And projected trends of increased blood pressure, cholesterol, and diabetes cases may result in an additional 23% increase in cardiac events. The risk factor trends alone may translate into 21.3 million more CVD events and 7.7 million related deaths between 2010 and 2030, researchers say.

Reducing smoking to 20% of the male population by 2020 and 10% by 2030 or lowering average systolic blood pressure by four points in men and women would significantly counteract adverse trends in other risk factors and prevent between 2.9 and 5.7 million deaths by 2030, according to the study. Aggressive antitobacco policies and preventive efforts aimed at controlling elevated blood pressure are two promising areas that need to be studied in more detail, Moran says.

— Source: Columbia University Medical Center