San Francisco, CA - Moderate alcohol intake raises plasma levels of adiponectin, a peptide that may curb inflammation and reduce CHD, researchers said at the American Heart Association 44th Annual Conference on Cardiovascular Disease Epidemiology and Prevention.

While moderate drinking and a higher intake of dietary fat were associated with increased adiponectin levels, a carbohydrate-rich diet with a high glycemic load was associated with lower levels of the cardioprotective peptide, Dr Tobias Pischon (Harvard School of Public Health, Boston, MA) and colleagues found.

Dietary habits play a decisive role in the development of CHD and type 2 diabetes, with moderate alcohol intake associated with a lower risk for CHD and a diet with a high intake of processed carbohydrates linked to a higher risk. However, the precise mechanisms underlying the relationship between diet and CHD risk have not yet been established.

Recent data from Pischon's group suggest that high levels of adiponectin, a newly discovered adipocyte-derived peptide involved in the development of atherosclerosis, are linked to a lower risk for CHD and diabetes. Obese patients and diabetics, on the other hand, have low plasma levels of adiponectin. In vitro experiments suggest the peptide improves insulin sensitivity and possesses anti-inflammatory and antiatherogenic effects. Based on these previous findings, the investigators assumed that adiponectin could mediate the relationship between dietary factors and CHD. In their study, aimed at exploring the influence of dietary factors on plasma adiponectin, they collected information on dietary habits, lifestyle, and anthropometric variables in 532 healthy men who were participating as controls in the Health Professionals Follow-up Study.

In multivariate models including age, smoking, history of hypertension and diabetes, physical activity, BMI, alcohol intake, and dietary intake, Pischon et al found moderate alcohol intake to be associated with the highest adiponectin levels.

In addition, participants with a high intake of dietary fat also showed high levels of adiponectin, whereas those who consumed a carbohydrate-rich diet with a high glycemic load had significantly decreased levels of the peptide (-1.3 mg/L per 1 SD increase in glycemic load).

"Our observations raise the hypothesis that adiponectin may be a mediator between dietary factors and coronary heart disease," says Pischon's group. Dietary factors and alcohol consumption, Pischon told heartwire, have been shown to affect insulin resistance. Adiponectin, in return, has been shown to improve insulin sensitivity. "It remains to be determined whether adiponectin is a causal mediator between diet, alcohol, and insulin sensitivity and what the mechanisms are," he said. Thus, the effect of dietary habits on plasma adiponectin levels now needs to be addressed and confirmed in interventional studies.