Differential relationships of hepatic and epicardial fat to body composition in HIV. Issue 19 (16th October 2017)

• Record Type: Journal Article
• Authors: Fourman, Lindsay T.; Lu, Michael T.; Lee, Hang; Fitch, Kathleen V.; Hallett, Travis R.; Park, Jakob; Czerwonka, Natalia; Weiss, Julian; Stanley, Takara L.; Lo, Janet; Grinspoon, Steven K.
• Is Part Of: Physiological reports. Volume 5:Issue 19(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-10-16
• Subjects: Ectopic fat -- Epicardial fat -- Nonalcoholic fatty liver disease (NAFLD) -- Subcutaneous adipose tissue -- Visceral adipose tissue; Physiology -- Periodicals; 571
• DOI: 10.14814/phy2.13386
• Languages: English
• ISSNs: 2051-817X

Abstract

Abstract: HIV‐infected patients commonly experience changes in central and peripheral fat content as well as ectopic fat accumulation. However, whether hepatic and epicardial fat stores relate differentially to body composition or how these associations are modified by HIV status has not been well explored. A previously recruited sample of 124 HIV‐infected patients and 58 healthy controls had undergone dual energy X‐ray absorptiometry (DEXA) and computed tomography (CT) from which body composition measures, liver–spleen ratio, and epicardial fat volume were obtained. Unique to the HIV‐infected group, there was a parabolic association between abdominal subcutaneous adipose tissue (SAT) area and liver–spleen ratio ( P = 0.03, inflection point 324 cm 2 ) such that hepatic fat content was greatest at the extremes of low and high SAT. A quadratic model also closely described the relationship between mean leg fat and liver–spleen ratio among patients with HIV ( P = 0.02, inflection point 4.7 kg), again suggesting greater liver fat content with both low and high leg fat. Notably, an analogous relationship of epicardial fat with SAT was not evident among HIV‐infected individuals or healthy controls. In contrast, visceral adipose tissue (VAT) linearly related to both liver–spleen ratio in HIV and epicardial fat volume irrespective of HIV status in multivariable models. In conclusion, our analyses implicate both low and high SAT as risk factors for hepatic fat accumulation in HIV. These findings add to growing evidence of SAT dysfunction in the setting of HIV infection, and highlight key physiologic differences between hepatic and epicardial fat depots. Abstract : We show a parabolic association between subcutaneous adipose tissue (SAT) area and liver–spleen ratio among HIV‐infected patients, which demonstrates for the first time that hepatic fat content is increased at the extremes of low and high SAT in this population. In contrast, an analogous relationship between SAT and epicardial fat is not evident, which instead relates more strongly to visceral fat. Our findings underscore important physiologic differences between ectopic fat depots, and have unique implications for the care of HIV‐infected patients with low SAT whose heightened risk of nonalcoholic fatty liver disease previously has not been well recognized.