Magnetic Resonance Spectroscopy of Hepatic Lipid Content and Associated Risk Factors in HIV Infection

Abstract

Liver-related illness is increasingly recognized as a source of morbidity in HIV-infected patients. Fatty infiltration of the liver is potentially an important consequence of HIV and treatment with antiretroviral (ARV) therapy. The aim of the present study was to evaluate HIV-infected men and women for hepatic steatosis using noninvasive magnetic resonance spectroscopy (MRS) and to assess the relationship between liver fat content, insulin resistance, and other associated risk factors. We examined 33 consecutively recruited HIV-infected adults without specific referral for liver disease. Subjects with alcohol abuse within 3 years or end-stage liver disease were excluded. The primary clinical measures were hepatic fat content measured by MRS, homeostasis model for assessment of insulin resistance (HOMA-IR), and body fat distribution assessed by cross-sectional computed tomography. We identified hepatic steatosis (liver fat content > or =5%) in 42% of subjects. Hepatic fat content was significantly correlated with HOMA-IR (r = 0.68, P < 0.0001) and increased visceral adiposity (r = 0.60, P < 0.001). Subjects with steatosis had significantly increased body mass index and alanine aminotransferase and triglyceride levels, with lower muscle attenuation (ie, increased intramuscular fat) compared to subjects without steatosis. However, steatosis was not related to duration of HIV, ARV exposure, or HCV coinfection. These data suggest that hepatic steatosis may be very common in HIV, not limited to those with HCV coinfection, and may play an important role in the metabolic profile among HIV-infected men and women.