Bril F, et al. - The physicians performed this study to examine the clinical and histologic characterization of nonalcoholic steatohepatitis (NASH) in African American patients. African Americans had lower intrahepatic triglyceride accumulation. However, once nonalcoholic fatty liver disease (NAFLD) developed, NASH occurred as frequently, and as severe, as in Caucasian patients. African Americans with NAFLD, thus, ought to be screened for NASH with the same degree of clinical resolve as in Caucasian patients.

Methods

• The physicians matched 67 African American patients to Caucasians (n = 134) in the ratio of 2:1, for age, sex, BMI, hemoglobin A_1c, and prevalence of type 2 diabetes mellitus (T2DM).
• Measurement of intrahepatic triglyceride content by proton MRS (¹H-MRS) was included in the screening for NASH, followed by a liver biopsy if patients had hepatic steatosis.
• They estimated insulin resistance during an oral glucose tolerance test using the Matsuda Index.

Results

• African American patients had a lower intrahepatic triglyceride content ([mean ± SD] 6.1 ± 6.8% vs. 9.4 ± 7.5%, P=0.007) and the presence of nonalcoholic fatty liver disease (NAFLD) was less common (25.0% vs 51.9%, P=0.003) as compared with Caucasians.
• However, in patients with NAFLD, prevalence of NASH was not different between ethnicities (57.1% vs. 73.3%, P=0.12).
• Furthermore, they revealed similar severity in each of the individual histological parameters (inflammation, ballooning, and fibrosis).
• Insulin resistance was similar between both ethnic groups among patients with NAFLD (Matsuda Index: 3.3 ± 1.8 vs. 3.1 ± 1.9, P=0.61; adipose tissue insulin resistance [Adipo-IR] index: 5.7 ± 4.6 vs 6.4 ± 4.7 mmol/L . μU/mL, P=0.53).
• However, insulin resistance appeared to be worse in African American vs Caucasian patients without NAFLD (Matsuda Index: 4.9 ± 3.6 vs. 7.0 ± 4.9 P=0.11; Adipo-IR: 3.9 ± 2.8 vs 2.7 ± 2.3 mmol/L . μU/mL, P=0.06).
• Moreover, African American patients had lower plasma triglycerides and higher HDL cholesterol, independent of the severity of intrahepatic triglyceride.