TUESDAY, Feb. 16, 2010 (HealthDay News) -- The use of cholesterol-lowering statin drugs increases the chance of developing diabetes by 9 percent, but the absolute risk is low, especially when compared with how much statins reduce the threat of heart disease and heart attack, new research shows.
The researchers analyzed data from 13 clinical trials of statins conducted between 1994 and 2009. The trials included a total of 91,140 people. Of those, 2,226 participants taking statins and 2,052 people in control groups developed diabetes over an average of four years.
Overall, statin therapy was associated with a 9 percent increased risk of developing diabetes, but the risk was higher in older patients. Neither body mass index nor changes in LDL (bad) cholesterol levels appeared to affect the statin-associated risk of developing diabetes.
There's no evidence that statin therapy raises diabetes risk through a direct molecular mechanism, but this may be a possibility, said study authors Naveed Satar and David Preiss, of the University of Glasgow's Cardiovascular Research Center, and colleagues.
The researchers noted that slightly improved survival among patients taking statins doesn't explain the increased risk of developing diabetes. They added that while it's highly unlikely, the increased risk of diabetes among people taking statins could be a chance finding.
To put their findings in context, the study authors pointed out that if 255 patients took statins for four years, there would be only one extra case of diabetes. However, for each millimole per liter reduction in LDL cholesterol achieved by taking statins, the same 255 patients would experience five fewer major coronary events, such as coronary heart disease death or non-fatal heart attack.
"In view of the overwhelming benefit of statins for reduction of cardiovascular events, the small absolute risk for development of diabetes is outweighed by cardiovascular benefit in the short and medium term in individuals for whom statin therapy is recommended," the researchers wrote in a news release.
"We therefore suggest that clinical practice for statin therapy does not need to change for patients with moderate or high cardiovascular risk or existing cardiovascular disease. However, the potentially raised diabetes risk should be taken into account if statin therapy is considered for patients at low cardiovascular risk or patient groups in which cardiovascular benefit has not been proven," they concluded.
The study authors also recommended monitoring of older people taking statins, since they have a higher risk of developing diabetes.
The findings were published online Feb. 16 and will appear in an upcoming print issue of The Lancet.
The benefit of taking statins to reduce cardiovascular risk greatly outweighs the risk of developing diabetes by a ratio of about 9:1, Dr. Christopher P. Cannon, of the cardiovascular division at Brigham and Women's Hospital and Harvard Medical School in Boston, wrote in an accompanying comment article.
"Nonetheless, this newly identified risk does warrant monitoring, and as such, in addition to periodic monitoring of liver-function tests and creatine kinase, it seems reasonable to add glucose to the list of tests to monitor in older patients on statins," Cannon said.
The U.S. Food and Drug Administration has more about statins.