Abstract and Introduction
It is well known that alcohol consumption is associated with type 2 diabetes mellitus. However, the association of age at initiation of alcohol consumption and duration of alcohol drinking with type 2 diabetes mellitus among Chinese adults is not fully understood. This study was based on data from the China Kadoorie Biobank, which included 512,712 participants aged 30–79 years who were living in China in 2004–2008. A Cox proportional hazards model was used to estimate the association of AAI and drinking duration with type 2 diabetes. After adjustment for potential covariates, ages at alcohol initiation (AAIs) of 18.1–29.0 years, 29.1–39.0 years, and >39.0 years were associated with 22% (95% confidence interval (CI): 14, 30), 25% (95% CI: 17, 33), and 32% (95% CI: 24, 39) lower hazards of type 2 diabetes compared with abstaining, respectively. Drinking durations of <10.1 years, 10.1–20.0 years, and 20.1–30.0 years were associated with a lower risk of type 2 diabetes, compared with abstaining. Among current (weekly) drinkers, AAI <18.1 years and drinking duration >30.0 years were associated with 18% (95% CI: 4, 33) and 20% (95% CI: 3, 40) higher hazards of type 2 diabetes, compared with AAI 18.1–29.0 years and drinking duration <10.1 years, respectively. In conclusion, late AAI and a short drinking duration were associated with a lower risk of type 2 diabetes in this large prospective cohort study of Chinese adults, but early AAI and long drinking duration were not.
Alcohol, one of the most popular drinks in the world, has been shown to contribute to serious disease burden. Globally, 5.1% of the global burden of disease and injury are attributable to alcohol consumption. Previous studies found that high intake of alcohol was directly or indirectly associated with type 2 diabetes mellitus, while moderate drinking might decrease the risk of type 2 diabetes.[3–5] In animal experiments, it was found that chronic alcohol consumption was associated with damage to the pancreas and development of diabetes, owing to pancreatic β-cell dysfunction and apoptosis.[6–8]
Some previous studies showed that early age at initiation of alcohol consumption, defined as age at alcohol initiation (AAI) less than 18 years, and long duration of alcohol drinking increased the risk of alcohol-use disorders, heavy drinking, and alcohol dependence.[9,10] In the United States, the National Epidemiologic Survey on Alcohol and Related Conditions found that the incidence of alcohol dependence for AAI less than 15 years was 1.38 times higher than that for AAI greater than 18 years. Alcohol dependence was associated with higher body mass index (BMI), more cigarette smoking, and a lower level of physical activity, which are associated with higher risk of metabolic diseases in Western populations.[11–13] However, the direct association of AAI and drinking duration with type 2 diabetes in China is largely unclear.
Therefore, in the present study, we tested our hypothesis that AAI and drinking duration contribute to the risk of developing type 2 diabetes, independent of daily alcohol consumption, among 0.5 million participants in a prospective Chinese cohort study, the China Kadoorie Biobank (CKB).
Am J Epidemiol. 2020;189(12):1478-1491. © 2020 Oxford University Press