The relationship between alcohol consumption, BMI, and type 2 diabetes: a systematic review and dose-response meta-analysis

Background

Moderate alcohol use may be associated with lower risk of type 2 diabetes mellitus (T2DM). Previous reviews have reached mixed conclusions.

Purpose

To quantify the dose-response relationship between alcohol consumption and T2DM, accounting for differential effects by sex and BMI.

Data Sources

Medline, Embase, Web of Science, and one secondary data source.

Study Selection

Cohort studies on the relationship between alcohol use and T2DM.

Data Extraction

Fifty-five studies, and one secondary data source, were included with a combined sample size of 1,363,355 men and 1,290,628 women, with 89,983 and 57,974 individuals, respectively, diagnosed with T2DM.

Data Synthesis

Multivariate dose-response meta-analytic random-effect models were used. For women, a J-shaped relationship was found with a maximum risk reduction of 31% (relative risk [RR] 0.69, 95% CI 0.64–0.74) at an intake of 16 g of pure alcohol per day compared with lifetime abstainers. The protective association ceased above 49 g per day (RR 0.82, 95% CI 0.68–0.99). For men, no statistically significant relationship was identified. When results were stratified by BMI, the protective association was only found in overweight and obese women.

Limitations

Our analysis relied on aggregate data. We included some articles that determined exposure and cases via self-report, and the studies did not account for temporal variations in alcohol use.

Conclusions

The observed reduced risk seems to be specific to women in general and women with a BMI ≥25 kg/m2. Our findings allow for a more precise prediction of the sex-specific relationship between T2DM and alcohol use, as our results differ from those of previous studies.