Eighteen-year alcohol consumption trajectories and their association with risk of type 2 diabetes and its related factors: the China Health and Nutrition Survey

Aims/hypothesis Alcohol consumption levels frequently fluctuate over the life course, but studies examining the association between alcohol consumption trajectories and type 2 diabetes are limited. This study aims to investigate the association of alcohol consumption trajectories with the risk of type 2 diabetes and its related factors. Methods Weighted longitudinal data were obtained for 12,186 adults who completed a questionnaire about alcohol consumption and diabetes status as part of the China Health and Nutrition Survey (1993-2011). Participants were designated into subgroups based on alcohol consumption trajectory, and subgroup analyses included 5436 individuals who were tested for specified diabetes-related factors. Light alcohol consumption was defined as fewer than seven standard drinks per week; moderate as 7-21 drinks per week; and heavy as more than 21 drinks per week. Latent class trajectory modelling was used to identify different alcohol consumption trajectories by sex. Multivariate Cox regression models and general linear regression models were used to assess association of trajectories with type 2 diabetes and its related factors. Results Compared with stable abstainers (individuals who never drank alcohol), two trajectories in men showing reduction to moderate or light levels after heavy alcohol consumption during early adulthood were significantly associated with increased risk of type 2 diabetes (HR 1.66 [95% CI 1.18, 2.33]; HR 1.93 [95% CI 1.01, 3.70]), while no significant association between trajectories and risk of type 2 diabetes was observed in women (p(for trend)=0.404). Triacylglycerol, HDL-cholesterol (HDL-C), uric acid and high sensitivity C-reactive protein were significantly higher in these two trajectories than other trajectories in men (all p<0.05), while only HDL-C showed significant increasing trends in women. Trajectories showing light-stable, or increase to moderate, levels were not associated with reduced risk of type 2 diabetes. Conclusions This study indicated that heavy alcohol consumption in early adulthood is significantly associated with increased risk of type 2 diabetes and higher levels of its biomarkers throughout adulthood in men. Gradually reducing alcohol consumption to moderate levels may not make a difference, which demonstrates the importance of alcohol intervention strategies in early adulthood. Although association between alcohol consumption and increased HDL-C levels has been observed, the results of this study did not support the hypothesis regarding the protective effect of moderate alcohol consumption on risk of type 2 diabetes in the Asian population.