Nonalcoholic fatty liver disease across ethno-racial groups: Do Asian-American adults represent a new at-risk population?

Background and Aim: Nonalcoholic fatty liver disease (NAFLD) is increasingly common worldwide. We explored clinical, laboratory, and histological features of NAFLD as well as risk factors for histologically advanced disease among under-represented ethno-racial groups. Methods: Patient records from one NAFLD clinic in California from 1998-2008 were reviewed. Biopsies were graded using Brunt criteria by a hepatopathologist blinded to clinical data. We used multivariate logistic regression to assess associations between ethno-racial group and histological severity of NAFLD, while controlling for other factors. Results: We identified 90 biopsy-proven cases of NAFLD. Mean age was 49years (standard deviation [SD]=11.6), and half were female. 52% of patients were Caucasian, 20% Latino-American, 18% Asian-American, and 10% Middle Eastern-American. There were significant differences among groups with respect to age, weight, body mass index (BMI), and grade of hepatic steatosis (all P<0.05). In multivariate analysis, older age was associated with severe (Brunt≥2) inflammation (odds ratio [OR] 1.1, P=0.002) and severe (Brunt≥3) fibrosis (OR 1.2, P=0.001), diabetes was associated with severe inflammation (OR 3.18, P=0.07) and severe fibrosis (OR 8.81, P=0.002), and increased BMI was associated with severe fibrosis (OR 2.43, P=0.07). Additionally, compared to Caucasians, Asian-Americans showed a trend toward an association with severe (Brunt>2) steatosis (OR 3.83, P=0.08) and severe inflammation (OR 5.42, P=0.06). Conclusions: The findings from this ethno-racially diverse clinic-based cohort are consistent with prior studies and also suggest that Asian-Americans may be at risk for advanced NAFLD. This may have implications for the prevention, evaluation, and treatment of patients with NAFLD that merit further study.