Ethnicity and nonalcoholic fatty liver disease : Hepatology (original) (raw)

Steatohepatitis/Metabolic Liver Disease

Bambha, Kiran1,†; Belt, Patricia2; Abraham, Maria2; Wilson, Laura A.2; Pabst, Mark3; Ferrell, Linda3; Unalp-Arida, Aynur2; Bass, Nathan3 for the Nonalcoholic Steatohepatitis Clinical Research Network Research Group

1 University of Colorado Denver, Aurora, CO

2 Johns Hopkins Bloomberg School of Public Health, Baltimore, MD

3 University of California San Francisco, San Francisco, CA

†Address reprint requests to: Division of Gastroenterology and Hepatology, University of Colorado Denver, 12631 East 17th Avenue, MS B-158, Aurora, CO 80045

Email:[email protected]

Received 15 July 2011; Accepted 22 September 2011

Potential conflict of interest: Nothing to report.

This work was supported by grants from the National Institutes of Health to the Nonalcoholic Steatohepatitis Clinical Research Network (U01DK61718, U01DK61728, U01DK61730, U01DK61731, U01DK61732, U01DK61734, U01DK61737, U01DK61738, and U01DK61713).

* Members of the Nonalcoholic Steatohepatitis Clinical Research Network Research Group are listed in the Supporting Information (see Appendix).

†fax: 303-724-1891

Abstract

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disorder in the United States; however, few data are available about racial and ethnic variation. We investigated relationships between ethnicity, NAFLD severity, metabolic derangements, and sociodemographic characteristics in a well-characterized cohort of adults with biopsy-proven NAFLD. Data were analyzed from 1,026 adults (≥18 years) in the Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) from 2004 to 2008, for whom liver histology data were available within 6 months of enrollment. Associations between ethnicity (i.e., Latino versus non-Latino white) and NAFLD severity (i.e., NASH versus non-NASH histology and mild versus advanced fibrosis) were explored with multiple logistic regression analysis. We also investigated effect modification of ethnicity on metabolic derangements for NAFLD severity. Within the NASH CRN, 77% (N = 785) were non-Latino white and 12% (N = 118) were Latino. Sixty-one percent (N = 628) had NASH histology and 28% (N = 291) had advanced fibrosis. Latinos with NASH were younger, performed less physical activity, and had higher carbohydrate intake, compared to non-Latino whites with NASH. Gender, diabetes, hypertension, hypertriglyceridemia, aspartate aminotransferase (AST), platelets, and the homeostasis model assessment of insulin resistance (HOMA-IR) were significantly associated with NASH. Age, gender, AST, alanine aminotransferase, alkaline phosphatase, platelets, total cholesterol, hypertension, and HOMA-IR, but not ethnicity, were significantly associated with advanced fibrosis. The effect of HOMA-IR on the risk of NASH was modified by ethnicity: HOMA-IR was not a significant risk factor for NASH among Latinos (odds ratio [OR] = 0.93; 95% confidence interval [CI]: 0.85-1.02), but was significant among non-Latino whites (OR, 1.06; 95% CI: 1.01-1.11).

Conclusion:

Metabolic risk factors and sociodemographic characteristics associated with NASH differ by ethnicity. Additional insights into NASH pathogenesis may come from further studies focused on understanding ethnic differences in this disease.

Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; BMI, body mass index; 95% CI, ninety-five percent confidence interval; DBP, diastolic blood pressure; GGT, gamma-glutamyl transferase; HDL, high-density lipoprotein; HS, high school; HOMA-IR, homeostasis model assessment of insulin resistance; LDL, low-densitylipoprotein; MET, metabolic equivalent; MRS, magnetic resonance spectroscopy; NAFLD, nonalcoholic fatty liver disease; NAS, Nonalcoholic Fatty Liver Disease Activity Score; NASH, nonalcoholic steatohepatitis; NASH CRN, Nonalcoholic Steatohepatitis Clinical Research Network; OR, odds ratio; PIVENS, Pioglitazone Versus Vitamin E Versus Placebo for Treatment of Non-Diabetic Patients With NASH trial; SBP, systolic blood pressure; WC, waist circumference.