Moderate Alcohol Use and Insulin Action in Chronic Hepatitis C Infection

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 prospective cohort of Latino individuals with and without HCV.

METHODS

One hundred fifty-three nondiabetic Latino individuals (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 two-step, 240-min 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 (>moderate). Multivariable models including HCV status assessed associations of alcohol use with baseline SSPG, hepatic IR and IS, and 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 while 60.4% had 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 cohort of Latino individuals, lifetime and current heavy alcohol use influenced hepatic IR and its change over time. Strategies to decrease rates of heavy alcohol use or increase abstinence along with lifestyle modification and anti-HCV therapy to reduce metabolic risk are critical to prevent adverse liver and metabolic outcomes in Latino individuals.

Impact of Moderate Alcohol Discontinuation on Insulin Action and Secretion in Latinos With and Without Hepatitis C

BACKGROUND

Insulin resistance (IR) is associated with hepatitis C virus (HCV), and Latinos are both at risk of IR and are disproportionately affected by HCV. Moderate alcohol consumption improves insulin sensitivity and may modify HCV-associated IR. We investigated the impact of moderate alcohol discontinuation on insulin sensitivity and secretion in Latinos using direct measurements.

METHODS

Twenty-five nondiabetic, noncirrhotic Latino adults without (n = 17) or with (n = 8) HCV underwent 3-day metabolic assessment before and after prescription of 6 weeks of moderate alcohol discontinuation. Peripheral IR was measured via steady-state plasma glucose (SSPG) and hepatic IR using endogenous glucose production during a 2-step 240-minute insulin suppression test. Insulin secretion was measured using graded glucose infusion test.

RESULTS

Baseline mean age was 46 ± 11 years, 63% male, 29% had HCV, and mean body mass index was 27 ± 4 kg/m² . Compared to non-HCV, HCV patients had a higher median SSPG (132 vs. 98.8 mg/dl, p = 1.0), hepatic IR (13.5 vs. 11.3, p = 0.24), and insulin secretion rate (ISR-AUC, 1,290 vs. 1,250 pmol/min, p = 0.98). After confirmed alcohol discontinuation, hepatic IR was the only parameter that changed significantly (increased, mean change 2.6 ± 4.8, p = 0.02). Higher baseline alanine aminotransferase (ALT) was also associated with a greater change in hepatic IR (average 4.0 points/ALT doubling, p = 0.004), and HCV was associated with a lesser change (average -7.3 points, p = 0.002), independent of ALT.

CONCLUSIONS

Short-term moderate alcohol discontinuation adversely impacted hepatic IR in Latinos which was influenced by level of ALT at baseline independent of etiology. Although reduction in ALT through weight loss and HCV eradication remains a priority in improving IR, the observed nonharmful effect of moderate alcohol use represents a potentially confounding variable that warrants further study.