The Relation of Light-to-Moderate Alcohol Consumption to Glucose Metabolism and Insulin Resistance in Nondiabetic Adults: the Moderating Effects of Depressive Symptom Severity, Adiposity, and Sex

Abstract

Purpose: We examined the relation of alcohol consumption to glucose metabolism and insulin resistance (IR) as a function of depressive symptoms, adiposity, and sex.

Method: Healthy adults (aged 18-65 years) provided fasting blood samples and information on lifestyle factors. Alcohol intake was categorized as never, infrequent (1-3 drinks/month), occasional (1-7 drinks/week), and regular (≥2 drinks/day) drinkers. The Beck Depression Inventory (BDI) was used to assess symptom severity. Primary outcomes were fasting insulin, glucose, and IR assessed by the homeostasis model assessment (HOMA).

Results: In univariate analysis, alcohol consumption was negatively associated with HOMA-IR (p = 0.03), insulin (p = 0.007), and body mass index (BMI) (p = 0.04), but not with glucose or BDI. Adjusting for potential confounders including BMI, alcohol consumption was associated with HOMA-IR (p = 0.01) and insulin (p = 0.009) as a function of BDI and sex. For women with minimal depressive symptoms, light-to-moderate alcohol consumption was associated with lower HOMA-IR and insulin. Alcohol consumption was not associated with metabolic markers in women with higher depressive symptoms and in men. In analysis using BMI as a continuous moderator, alcohol consumption was only associated with insulin (p = 0.004). Post-hoc comparisons between BMI groups (<25 vs ≥25 kg/m²⁾ revealed that light-to-moderate alcohol consumption was associated with lower insulin but only in subjects with BMI ≥ 25 kg/m².

Conclusions: The benefits of light-to-moderate alcohol consumption on fasting insulin and IR are sex dimorphic and appear to be independently moderated by adiposity and depressive symptom severity.

Keywords: Adiposity; Alcohol consumption; Depressive symptom severity; Insulin resistance.

Fig. 1a, b

Log(HOMA-IR) according to category of alcohol intake (a never vs infrequent; b never vs occasional/regular) and depressive symptom severity in women. The statistical interaction between alcohol intake and depressive symptom severity is plotted at 0.5 SD above (high) and below (low) the total mean of the sample on the Beck Depression Inventory. Regression lines were generated using a model that adjusted for age, BMI, race, education, and physical activity