Association of change in alcohol consumption on fasting serum glucose, insulin resistance, and beta cell function among Korean men.

We aimed to determine the association between alcohol consumption change on fasting serum glucose, insulin resistance, and beta cell function. The study population consisted of 55,858 men from the Kangbuk Samsung Health Study. Participants were divided into non-, light, moderate, and heavy drinkers for each of the first and second health examinations based on a self-reported questionnaire on alcohol consumption. The adjusted mean values for change in fasting serum glucose (FSG), homeostatic model assessment of insulin resistance (HOMA-IR), and beta cell function (HOMA-β) levels were determined according to alcohol consumption change by linear regression. Compared to sustained initial drinkers, those who increased alcohol intake to moderate (p < 0.001) and heavy (p < 0.001) levels had increased FSG levels. In contrast, reduction in alcohol intake to light levels among initial heavy drinkers was associated with reduced change in FSG levels (p = 0.007) compared to sustained heavy drinkers. No significant associations were observed between changes in alcohol intake with HOMA-IR levels. Compared to sustained light drinkers, those who increased alcohol intake to moderate (p < 0.001) and heavy (p = 0.009) levels had lower increases in HOMA-β levels. Finally, compared to sustained heavy drinkers, those who reduced alcohol consumption to light levels had greater increases in HOMA-β levels (p = 0.002). Increases in alcohol consumption were associated with higher blood glucose levels and worsened beta cell function. Heavy drinkers who reduce alcohol intake could benefit from improved blood glucose control via improved beta cell function.