By David Douglas
NEW YORK (Reuters Health) – Elevated levels of leptin in plasma may be an independent risk factor for the development of cardiovascular disease, according to researchers in Scotland.
In fact, Dr. Naveed Sattar of Glasgow Royal Infirmary, told Reuters Health that "leptin appears to be as strong a predictor as some well-recognized risk factors such as systolic blood pressure or high-density lipoprotein (HDL) cholesterol." This, he added, is "probably because it is such a good marker of the amount of fat tissue in the body."
Using samples from a large-scale study begun in 1989, Dr. Sattar and colleagues measured baseline plasma leptin levels in 377 men who had had a coronary event during 5 years of follow-up. They were matched for age and smoking history with 783 controls who had had no such event during the follow-up period. The findings appear in the December 18th issue of Circulation: Journal of the American Heart Association.
Leptin levels were significantly higher in cases than controls (5.87 ng/mL versus 5.04 ng/mL). Furthermore, for each standard deviation of increase in leptin, the relative risk of a coronary event increased by 1.25. Correcting for factors, including body mass index and systolic blood pressure, led to "minimal change" in the risk ratio.
Leptin and C-reactive protein (CRP) levels were correlated, but even allowing for this, leptin was still a significant predictor of coronary events. Furthermore, "the addition of leptin into the model resulted in CRP's loss as an independent predictor."
"This is the first evidence that leptin may be an independent risk factor for the development of coronary heart disease," Dr. Sattar continued. However, "the results must be confirmed by other researchers before we consider using leptin in the prediction of heart disease risk."
Nevertheless, he also pointed out that "regular exercise can have immediate effects on leptin levels because it reduces the body's fat content, even in the absence of weight loss".