Role of ethnicity in overweight and obese subjects with nonalcoholic steatohepatitis (NASH)†

Steatohepatitis and Metabolic Liver Disease


Romina Lomonaco1,5, Carolina Ortiz-Lopez1,5, Beverly Orsak1, Joan Finch1,5, Amy Webb2,5, Fernando Bril1, Christopher Louden3, Fermin Tio4,5, Kenneth Cusi1,5,*,‡DOI: 10.1002/hep.24483

Abstract


The role of ethnicity in determining disease severity in NASH remains unclear. To better understand this, we recruited 152 subjects with biopsy-proven NASH (Hispanics: 63%; Caucasians: 37%). Both groups were well matched for age, gender and total body fat.
We measured:
1) liver fat (LFAT) by magnetic resonance imaging and spectroscopy (MRS);
2) fasting glucose, insulin (FPI) and free fatty acid (FFA) levels;
3) total body fat (TBF) by dual energy x-ray absorptiometry (DXA);
4) liver and muscle (Rd) insulin sensitivity (insulin clamp with 3-[3H] glucose);
5) insulin resistance at the level of the liver (fasting endogenous glucose production derived from 3-[3H] glucose infusion x FPI) and adipose tissue (fasting FFA x FPI).
LFAT was slightly, but not significantly, higher in Hispanics vs. Caucasians (27±2% vs. 24±2%, p=0.16). However, this trend did not translate into worse liver histology (stetaosis, necroinflammation or fibrosis, all NS). Patients with NASH had severe hepatic, adipose tissue and muscle insulin resistance vs. subjects without NAFLD (p<0.01-p<0.0001), but there were no differences between both ethnic groups on these parameters. However, Hispanics vs. Caucasians with T2DM had a trend for worse hepatic/adipose tissue insulin resistance and fibrosis (p=0.052).

Conclusion:

when Hispanics and Caucasians with NASH are well matched for clinical parameters, in particular for adiposity, the slightly higher LFAT content is not associated with worse hepatic insulin resistance or more severe NASH on histology. Hispanic ethnicity does not appear to be a major determinant of disease severity in NASH, although those with diabetes may be at greater risk of fibrosis. Given the higher risk of T2DM in Hispanics, long-term studies are needed to define their risk of disease progression.
(HEPATOLOGY 2011.)