Alcohol and type 2 diabetes. A review.

AIMS: To describe a) the association between alcohol consumption and the risk of type 2 diabetes (T2D) and b) the impact of alcohol on the glycemic control with and without anti-diabetic drugs. DATA SYNTHESIS: We searched MEDLINE and the Cochrane Library data base with the key words "Diabetes Mellitus, type 2" and "Alcohol Drinking" in English-language studies in adults. For the first part of the review we selected meta-analyses, review articles and observational studies more recent than year 1990 including at least 1000 participants. For the second part of the review we included all articles more recent than year 1990. Most observational studies find a J-shaped association between alcohol intake and incidence of T2D. Interestingly, drinking pattern plays a role, i.e. binge drinking increases the risk of T2D. Opposing information exists about the influence of beverage type. In T2D the acute effects on plasma glucose, insulin, fatty acids and triglyceride vary, in part depending on concomitant intake of food. Acute alcohol intake does not induce hypoglycemia in diet treated T2D, but increases the risk of hypoglycemia in sulphonylurea treated patients. In most studies, long-term alcohol use is associated with improved glycemic control in T2D. CONCLUSIONS: Alcohol consumption reduces the incidence of T2D, however, binge drinking seems to increase the incidence. Acute intake of alcohol does not increase risk of hypoglycemia in diet treated subjects with T2D, only when sulphonylurea is co-administered. Long-term alcohol use seems to be associated with improved glycemic control in T2D probably due to improved insulin sensitivity.