The impact of visceral fat in nonalcoholic fatty liver disease: cross-sectional and longitudinal studies

Background. Nonalcoholic fatty liver disease is increasing worldwide, and attention is being paid to its association with obesity and metabolic syndrome. The aim of this study was to elucidate the role of visceral fat accumulation in hepatic steatosis by cross-sectional and longitudinal studies. Methods. We enrolled 125 patients in a cross-sectional study and 28 patients in a longitudinal study and examined visceral and subcutaneous fat thickness, hepatic steatosis score, and biochemical parameters. In the longitudinal study, the influence of weight change on fat distribution and hepatic steatosis was investigated. Results. In the cross-sectional study, the severity of hepatic steatosis showed a significant positive correlation with body mass index, visceral fat thickness, serum albumin, alanine aminotransferase (ALT), cholinesterase, fasting insulin, and the homeostasis model assessment of insulin resistance. ALT, visceral fat thickness, and serum albumin were independent factors for hepatic steatosis. In the longitudinal study, visceral fat thickness fluctuated closely with changes in body weight, and had the strongest relationship with the change of hepatic steatosis by multivariate analysis. Conclusions. Visceral fat was the most important factor for the development of hepatic steatosis. Visceral fat thickness can be measured by sonography easily, noninvasively, and repeatedly for assessment of central obesity and monitoring of the efficacy of treatment of nonalcoholic fatty liver disease.