The Prevalence and Clinical Correlates of Nonalcoholic Fatty Liver Disease (NAFLD) in African Americans: The Multiethnic Study of Atherosclerosis (MESA)

Abstract

Nonalcoholic fatty liver disease (NAFLD) is the number one cause of liver disease in the United States. The prevalence rates in African Americans (AA), while significantly lower than other ethnic groups with similar known risk factors, have been quoted as high as 24 %. We aim to determine if the presence of NAFLD in African Americans is associated with lower triglyceride and/or higher HDL-c levels and if NAFLD risk factors in African Americans differ from other ethnic groups. A total of 3,056 participants of the Multi Ethnic Study of Atherosclerosis were included in this study. We utilized the baseline serum, anthropometric and radiographic measurements obtained between 2000 and 2002. NAFLD was defined as liver spleen ratio <1 from CT measurements. The prevalence of NAFLD was and 11 % in AA. We found that age, education, triglyceride levels, HDL-c levels, waist circumference and HOMA-IR were independent correlates of NAFLD in this population. Among those with NAFLD, AA had significantly lower triglyceride levels than Hispanics [125 mg/dl (95 % CI 107-143) versus 192 mg/dl (95 % CI 169-215), p < 0.001] and Caucasians [185 mg/dl (95 % CI 161-209), p = 0.001]. Serum HDL-c was significantly higher in AA with NAFLD (47 mg/dl; 95 % CI 45-50) when compared to Hispanics (44 mg/dl; 95 % CI 43-66, p = 0.02) and Caucasians (44 mg/dl; 95 % CI 42-46, p = 0.02) with NAFLD. This study demonstrated that the clinical correlates of NAFLD in African Americans are similar to the correlates of NAFLD in other ethnic groups. Our data also suggests that when evaluating African Americans for NAFLD risk, lower cutoff values should be used to define abnormal triglyceride levels.