Patients with nonalcoholic fatty liver disease who consumed modest quantities of alcohol had significantly less improvement in steatosis and significantly lower odds of resolution of nonalcoholic steatohepatitis, compared with nondrinkers, according to the results of a longitudinal cohort study published in the Clinical Gastroenterology and Hepatology.
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Modest drinkers also had significantly less improvement in their AST levels, compared with nondrinkers, said Veeral Ajmera, MD, of the University of California, San Diego, and his associates. “Importantly, our results suggest that cessation of alcohol use may mitigate these changes,” they wrote. Clinicians should consider the spectrum of nonalcoholic fatty liver disease (NAFLD), and especially nonalcoholic steatohepatitis (NASH), when making recommendations about alcohol use. “More advanced NAFLD severity may warrant counseling against [even] modest alcohol use.”
More than one in three adults in the United States has NAFLD and about two-thirds drink alcohol, almost always in moderation, the researchers noted. Modest alcohol use has been linked to decreased cardiovascular risk, which is particularly relevant because patients with NAFLD tend to have risk factors for cardiovascular disease. Results from at least two cross-sectional studies also suggest modest drinkers with NAFLD have less severe histology, including less NASH and fibrosis. However, modest drinkers tend to be more physically active, with lower body mass indices, higher physical activity levels, and less obesity, which are potential confounders. To better understand the effects of modest alcohol consumption on NAFLD, the researchers studied adults with NAFLD who participated in studies conducted by the multicenter NASH Clinical Research Network.
The 285 participants were typically aged in their late 40s, female, white, and obese, with an average body mass index of 34.7 kg/m2. In all, 168 participants (59%) reported consuming up to two drinks per day, while 41% abstained from alcohol use. During an average of 47 months between biopsies (standard deviation, 26 months), nondrinkers averaged a 0.49 reduction in steatosis grade, significantly more than that of modest drinkers (reduction, 0.30; P = .04). Nondrinkers also had a greater decrease in mean AST level (7 U/L), compared with drinkers (2 U/L; P = .04).
A total of 64% of patients were classified as having definite NASH, 19% had NAFLD without NASH, and 17% had borderline NASH. At baseline, 23% of patients did not have fibrosis, 32% had stage 1 fibrosis, 21% had stage 2, 21% had stage 3, and 3% had stage 4. Modest drinkers were more likely to be white and were less likely to be diagnosed with definitive NASH at baseline. After controlling for these potential confounders, modest drinkers had significantly lower odds of NASH resolution, compared with nondrinkers (adjusted odds ratio, 0.32; 95% confidence interval, 0.11-0.92; P = .04).
“[The] presence of NASH has consistently been shown to predict increased risk for fibrosis progression, and therefore, our finding of less NASH resolution among consistent modest drinkers is clinically relevant,” the investigators wrote. “Although we were unable to assess the association between modest alcohol consumption and cardiovascular risk, we did not see any significant changes in measured metabolic risk factors with known associations with cardiovascular disease including low-density lipoprotein and high-density lipoprotein cholesterol and insulin resistance.”
Funders of the study included the National Institute of Diabetes and Digestive and Kidney Diseases, the National Center for Advancing Translational Sciences, the Advanced/Transplant Hepatology Fellowship, the American Association for the Study of Liver Diseases Foundation, and the Intramural Research Program of the National Institutes of Health.
SOURCE: Ajmera V et al. Clin Gastroenterol Hepatol. 2018 Mar 14. doi: 10.1016/j.cgh.2018.01.026.