Is NASH underdiagnosed among African Americans?

Abstract

Objective: Obesity and type 2 diabetes mellitus are considered risk factors for nonalcoholic steatohepatitis (NASH) and cryptogenic cirrhosis. Because obesity and type 2 diabetes are prevalent among African American females by the 5th and 6th decades, one would expect an increased number of African Americans among patients with NASH and cryptogenic cirrhosis.

Methods: We determined the percentage of patients of African American and European American descent among all of the patients in our liver disease registry and those with NASH and cryptogenic cirrhosis. We also assessed the ethnicity of patients in our registry with other common liver diseases including hepatitis C, and we determined the ethnicity of patients seen at our center with type 2 diabetes and a primary diagnosis of obesity over a 4-yr period. Using census data, we compared these results to our local and regional ethnic demographics.

Results: Overall, 199 of 2,253 patients (9%) in the registry were of African American descent, whereas 1,906 were of European American descent (85%). This distribution is similar to the ethnic mix in central Virginia (12% African American, 86% European American) and Albemarle County (12% African American, 83% European American). The prevalence of African American patients among individuals seen at our center for either type 2 diabetes or a primary diagnosis of obesity was over two times the prevalence of African Americans in the county or regional population. In contrast, of 159 NASH patients only one (0.6%) was of African American descent and 154 (97%) were of European American descent (p < 0.001 compared to the total registry, county, or region). Among 206 cryptogenic cirrhosis patients, only two (1%) were of African American descent, whereas 195 (95%) were of European American descent (p < 0.001 compared to the total registry). With regard to other liver diseases, African American patients were slightly overrepresented among hepatitis C patients and markedly overrepresented among patients with hepatic sarcoidosis, similar to previously reported national figures.

Conclusion: Although there is overrepresentation of African Americans among patients with major risk factors for NASH, individuals of primarily African American descent are infrequently represented among our patients with NASH or cryptogenic cirrhosis. This could result from underrecognition, underreferral, or a true lower prevalence of these disorders among African Americans.