Background and aims: Low serum 25-hydroxyvitamin D (25(OH)D) is associated with higher nonalcoholic fatty liver disease (NAFLD) risk in studies of mainly white participants. Significant racial/ethnic differences exist in serum 25(OH)D and NAFLD prevalence questioning extending this association to other racial/ethnic groups. We tested whether the association between serum 25(OH)D and NAFLD vary by race/ethnicity.
Methods and results: This was a cross-sectional analysis from the Multi-Ethnic Study of Atherosclerosis (MESA) that included 3484 participants (44% male; 38.4% Whites, 27.8% African-Americans, 23.5% Hispanics, and 10.3% Chinese-Americans) who had serum 25(OH)D and upper abdominal CT images available at baseline. Serum 25(OH)D was measured by high-performance liquid chromatography-tandem mass spectrometry. NAFLD was identified if liver-to-spleen Hounsfield-Unit ratio was <1. Whites had the highest 25(OH)D level and African-Americans had the lowest level (mean ± SD: 29.5 ± 10.4 vs.19.9 ± 9.1, respectively). Six hundred and eleven (17.5%) participants had NAFLD; Hispanics had the highest prevalence (26.2%) followed by Chinese-Americans (19.8%), Whites (15.8%) and African-Americans (11.7%), P < 0.0001. In adjusted model, the association of 25(OH)D with NAFLD differed by race/ethnicity (P < 0.0001). Negative association was only evident in Causations (OR (95% CI):1.23 (1.03, 1.47) per 1 SD lower serum 25(OH)D). For other racial/ethnic groups, BMI, triglycerides, diabetic status and/or smoking, but not serum 25(OH)D, were common independent risk factors for NAFLD.
Conclusions: The negative association between serum 25(OH)D and NAFLD in Whites may not be broadly generalizable to other racial/ethnic groups. Modifiable risk factors including BMI, triglycerides, diabetic status and/or smoking associate with NAFLD risk in non-white racial/ethnic groups beyond 25(OH)D.
Keywords: Nonalcoholic fatty liver disease; Race/ethnic groups; Risk factors; Serum 25-hydroxyvitamin-D.
Copyright © 2019 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.