The relationship between alcohol and glycohemoglobin 

With the rising prevalence of type 2 diabetes mellitus (T2DM), there is debate regarding biological and psychosocial risk factors. While it is well established that alcohol lowers glycohemoglobin (HbA1c) levels, it is less clear whether alcohol consumption is protective of T2DM. It is also unclear how gender and ethnicity influence the utility of HbA1c screening as a tool for T2DM diagnosis, particularly in the context of alcohol use.
A cross-sectional study utilised the National Health and Nutrition Examination Survey 2013-2014 dataset and was restricted to adults 20 years and older, nonpregnant, and not on antihypertensive medication (n = 4299) to evaluate the relationship between alcohol use and HbA1c. A multilinear regression model controlled for gender, ethnicity,
education level, body mass index, and age.
After controlling for covariates, both moderate (β = -0.073; p = 0.033) and heavy drinking (β = -0.167; p < 0.001) are associated with reduced HbA1c levels. Additionally, female gender is a significant negative predictor of HbA1c (β = -0.052; p = 0.024) and all ethnic groups have higher levels of HbA1c compared with non-Hispanic whites.
The clinical utility of HbA1c as a screening tool for T2DM without considering alcohol use, gender, and ethnicity may lead to diagnostic errors. Individualised approaches and focused efforts toward health equity are needed to address rising rates of T2DM.
Source: The Relationship Between Alcohol and Glycohemoglobin: A Biopsychosocial Perspective. Wiss DA. Biores Open Access. 2019 Oct 3;8(1):146-154.