Optimal vitamin D status decreases the increase in systolic blood pressure seen with aging in white Americans
There is a prevalence of both hypertension and a lack of vitamin D in residents of the United States. Recent clinical trials and animal studies have suggested that vitamin D insufficiency is likely associated with elevated blood pressure.
Scientists at Emory University School of Medicine, Atlanta, GA used cross-sectional data to determine whether vitamin D concentrations were related to systolic blood pressure (SBP) in the third National Health and Nutrition Examination Survey.
Blood pressure was classified into 5 categories with a sixth category added to distinguish participants with normal SBP (<110 mm Hg) from those with high-normal SBP (110–119 mm Hg). The level of serum 25 hydroxyvitamin vitamin D was estimated. The researchers used linear regression to explore the association between vitamin D, blood pressure, and age.
Lower serum levels of Vitamin D were associated with a higher blood pressure category in whites. However, when controlling for age, the association was no longer significant. But on the other hand having the most optimal level of Vitamin D greater than 80 nmol/L decreased the age-related increase in SBP by 20% compared with participants having concentrations less than 50 nmol/L. Only 8% of blacks had Vitamin D levels greater than 80 nmol/L. The study is published in the January 2008 issue of the American Journal of Clinical Nutrition.
Cholesterol Drug Zetia Doesn't Cut Heart Attack Risk
The long-awaited results of a trial of Zetia, a cholesterol-lowering drug prescribed to about a million Americans, shows the drug confers no medical benefit to users.
In fact, the pace at which artery-clogging plaques formed within vessels almost doubled in patients taking Zetia along with another cholesterol-lowering drug, Zocor, compared to those taking Zocor alone, the study found.
The two medications are also marketed together in one prescription pill, called Vytorin. About 60 percent of U.S. patients who are taking Zetia now receive the drug as part of Vytorin. These results might also pertain to Vytorin, which contains Zetia, experts say
But the new two-year trial of 720 patients sheds doubt on whether it makes any sense for people battling cholesterol to take Vytorin instead of Zocor alone, experts said. The study was funded by the two companies that make Zetia, Merck and Schering-Plough.
No one is disputing that Zetia can lower levels of LDL "bad" cholesterol by 15 percent to 20 percent -- that had been shown in previous trials. However, whether that reduction led to any greater lowering of heart attack or stroke risk had remained unclear.
The new ENHANCE trial -- which involved patients with a genetic condition that causes abnormally high levels of blood cholesterol -- found no such added benefit. According to a statement released by the two drug companies Monday, researchers found no statistically significant difference in heart attacks or stroke among trial participants who took Zetia plus Zocor, a widely used cholesterol-lower drug, versus those who got Zocor alone.
The study also noted that the speed at which arteries thickened with plaque almost doubled among those on the two-drug regimen compared to those taking Zocor alone.