To assess differences in characteristics and disease progression in lean (BMI <25) compared to obese (BMI >30) patients with NASH/NAFLD.
US EMR data were limited to adults with NASH/NAFLD (ICD10 K76, 75.81) with BMI <25 or ≥30 but without viral hepatitis, advanced liver disease or evidence of alcohol abuse. Baseline date was the first calculable FIB4 between July 2015 - Jun 2017 with >1 year history and >2 years follow-up or death. Definition of advanced liver disease (ALD): cirrhosis (compensated/decompensated), hepatocellular carcinoma, liver transplant. Observed incidence rates were cases per 1000 person-years to event, death, or end of observation (Jun 2019); differences between groups assessed by log-rank. Propensity score matching (PSM) adjusted for age, race, gender, baseline FIB4, comorbidities, and use of GLP-1 receptor agonists, SGLT-2 inhibitors and statins.
Of 6806 patients, 1232 (18%) were lean and 5574 (82%) obese with median follow-up of 2.6 and 2.9 years respectively. Obese had lower proportions of age ≥75 (5% vs 11%, p<0.001), females (60% vs 70%, p<0.001), and FIB4 ≥2.67 (6% vs. 12%, p<0.001) and higher proportions of diabetes (41% vs. 20%, p<0.001), hypertension (52% vs 37%, p<0.001), hyperlipidemia (65% vs 40%, p<0.001), and statin use (43% vs 28%, p<0.001). PSM yielded 1184 pairs. Incidence [CI] of ALD was significantly higher in lean vs obese in full (115.37 [103.02-128.8] v. 65.94 [61.86-70.21], p<0.001) and matched cohort comparisons (115.95 [103.32-129.7] v. 71.96 [62.76-82.12], p<0.001). Incidence rates increased with increasing FIB4 score and significant differences between lean and obese group rates were limited to patients with less severe fibrosis (FIB4 <2.67).
Lean NASH/NAFLD patients were more likely to develop ALD compared to obese. However, in patients with severe fibrosis (FIB4 ≥2.67), which had the highest incidence rates of ALD, rates were not statistically different between lean and obese groups.
© 2020 Published by Elsevier Inc.