Disentangling the impact of alcohol use and hepatitis C on insulin action in Latino individuals.

Background Alcohol, insulin resistance (IR), and hepatitis C (HCV) are all significant contributors to adverse outcomes of chronic liver disease. Latinos are disproportionately affected by these risk factors. We investigated the relationship between alcohol use and insulin action in a large prospective Latino cohort with and without HCV. Methods One hundred fifty-three non-diabetic Latinos (60 HCV+, 93 HCV-) underwent clinical evaluation and metabolic testing; 56 had repeat testing over a median follow-up of 1.5 years. Peripheral IR and hepatic IR were measured via steady-state plasma glucose (SSPG) and endogenous glucose production during a 2-step 240-minute insulin suppression test. Insulin secretion (IS) was measured using the graded glucose infusion test. Alcohol use was categorized as none, moderate (≤1 drink/day for women and ≤2 drinks/day for men), and heavy (not moderate). Multivariable models including HCV status assessed associations of alcohol use with baseline SSPG, hepatic IR and IS, and with changes in these parameters over time. Results Overall, the median age was 44 years, 63.4% were male, 66.7% overweight/obese, and 31.9% had heavy lifetime alcohol use (60.4% moderate lifetime alcohol use). SSPG and IS were similar by levels of alcohol use at baseline and alcohol use was not statistically significantly associated with change in these measures over time. However, lifetime daily heavy alcohol use (vs not heavy, coef 2.4 μU-mg/kg-min-ml, p=0.04) and HCV status (coef 4.4 μU-mg/kg-min-ml, p=0.0003) were independently associated with higher baseline hepatic IR, and current heavy alcohol use was associated with greater change in hepatic IR in follow-up (coef 5.8 μU-mg/kg-min-ml, p=0.03). Conclusions In this Latino cohort, lifetime and current heavy alcohol use influenced hepatic IR and its change over time. Strategies to improve rates of alcohol cessation along with lifestyle modification and anti-HCV therapy to reduce metabolic risk are critical to prevent adverse liver and metabolic outcomes in Latinos.