This article is more than 5 years old. Information may no longer be current.

Ethnicity affects propensity for intra-abdominal, hepatic fat storage

Propensity to store fat intra-abdominally varies significantly by ethnicity and race, with higher rates seen in Japanese Americans and lower rates seen in African Americans compared with other groups, according to data published in Gastroenterology.

The extensive heterogeneity across ethnicity to store fat should be highlighted as nonalcoholic fatty liver disease and nonalcoholic steatohepatitis rates continue to rise, according to Unhee Lim, PhD, from the University of Hawaii, and colleagues.

“Ethnicity, along with male sex and older age, are among the few known determinants of body fat deposition in ectopic abdominal regions, rather than as subcutaneous adipose tissue,” Lim and colleagues wrote. “These findings ... implicate body fat distribution as a cause of metabolic disease risk beyond what is explained by overall adiposity, especially in Asian Americans and Native Hawaiian women.”

The Multiethnic Cohort Study comprised 1,794 adults aged 45 years to 75 years from five ethnic groups including Japanese Americans, Native Hawaiians, Caucasians, African Americans and Latinos.

The researchers observed the highest mean trunk, visceral and liver fat measurements in Japanese Americans and the lowest measurements in African Americans with intermediate results in the other three groups (P < .0001).

The prevalence for NAFLD also differed significantly between Japanese Americans (57% in men, 72% in women) and African Americans (12% in men, 19% in women), although the prevalence was lower after adjusted analysis for Japanese Americans (38% for men, 46% for women).

Regarding adult weight change from age 21 years, Japanese Americans also had the highest rates of visceral and liver fat increases while African Americans had the lowest.

Mediation analysis showed that African Americans had a lower likelihood for metabolic syndrome compared with Caucasians, in part mediated through their lower relative intra-abdominal adiposity. The researchers observed the opposite prevalence in Japanese Americans and Native Hawaiian women.

Lim and colleagues noted that while genetic and specific lifestyle factors may account for ethnic and racial variation in body fat distribution, their results are independent of the PNPLA3 rs783409 genetic variant (associated with hepatic adiposity), age, menopause, smoking and alcohol intake. – by Talitha Bennett

Disclosure: Lim reports no relevant financial disclosures. Please see the full study for the other authors’ relevant financial disclosures.