Effect of alcohol consumption on diabetes mellitus: a systematic review.

BACKGROUND: Both diabetes mellitus and alcohol consumption are prevalent in the United States, yet physicians are poorly informed about how alcohol use affects risk for or management of diabetes.
PURPOSE: To conduct a systematic review assessing the effect of alcohol use on the incidence, management, and complications of diabetes mellitus in adults. DATA SOURCES: English-language studies in persons 19 years of age or older that were identified by searching the MEDLINE database from 1966 to the third week of August 2003 and the reference lists of key articles. STUDY SELECTION: Two independent assessors reviewed 974 retrieved citations to identify all experimental, cohort, or case-control studies that assessed the effect of alcohol use on diabetes risk, control, self-management, adverse drug events, or complications. DATA EXTRACTION: Two independent reviewers extracted data and evaluated study quality on the basis of established criteria. DATA SYNTHESIS: Thirty-two studies that met inclusion criteria were reviewed. Compared with no alcohol use, moderate consumption (one to 3 drinks/d) is associated with a 33% to 56% lower incidence of diabetes and a 34% to 55% lower incidence of diabetes-related coronary heart disease. Compared with moderate consumption, heavy consumption (>3 drinks/d) may be associated with up to a 43% increased incidence of diabetes. Moderate alcohol consumption does not acutely impair glycemic control in persons with diabetes.
CONCLUSIONS: Moderate alcohol consumption is associated with a decreased incidence of diabetes mellitus and a decreased incidence of heart disease in persons with diabetes. Further studies are needed to assess the long-term effects of alcohol consumption on glycemic control and noncardiac complications in persons with diabetes.