Association between Sarcopenic Obesity Status and Nonalcoholic Fatty Liver Disease and Fibrosis

Abstract

Background/Aims: There are no data regarding the association between sarcopenic obesity status and nonalcoholic fatty liver disease (NAFLD) and NAFLD-associated liver fibrosis. Therefore, we aimed to investigate the relationship between sarcopenic obesity status (sarcopenia only, obesity only, and sarcopenic obesity) and NAFLD and liver fibrosis in Korean adults.Methods: In total, 2,191 subjects completed a health checkup program, including abdominal ultrasonography and FibroScan. Subjects were classified into the following four categories: optimal body composition (nonobese and nonsarcopenic), sarcopenia only (nonobese), obesity only (nonsarcopenic), and sarcopenic obesity. Sarcopenic obesity was stratified by the skeletal muscle mass index and body fat using bioelectrical impedance analysis. NAFLD was diagnosed by ultrasonography, and liver fibrosis was assessed using transient elastography in subjects with NAFLD. Results:The prevalence of NAFLD and liver fibrosis significantly increased according to the sarcopenic obesity status. In the logistic regression analysis, after adjusting for multiple risk factors, the odds ratio (OR) for the risk of NAFLD was largest in the sarcopenic obesity group (OR, 3.68; 95% confidence interval [CI], 2.94 to 4.60), followed by the obesity only (OR, 2.25; 95% CI, 1.67 to 3.03) and sarcopenia only (OR, 1.92; 95% CI, 1.30 to 2.84) groups, when compared with the optimal group. Additionally, liver fibrosis was independently associated with sarcopenic obesity status (OR 4.69, 95% CI 1.95 to 11.29; OR 4.17, 95% CI 1.56 to 11.17; OR 3.80, 95% CI 0.86 to 16.75, respectively). Conclusions:These results demonstrated that sarcopenic obesity was independently associated with NAFLD and liver fibrosis and increased the risk of NAFLD and liver fibrosis more than obesity or sarcopenia alone.

Sarcopenic Obesity, the Possible Culprit for Nonalcoholic Fatty Liver Disease or Fibrosis

“… 2 For instance, NAFLD can lead to sarcopenia by activating myostatin, and low skeletal muscle mass can induce liver damage by activating the myostatin receptor in hepatic stellate cells. 9 Although Song et al 4 provided important evidence for this association, a cause-effect relationship cannot be accurately assessed in this study of cross-sectional observational design. In this regard, Sinn et al 10 recently conducted a longitudinal analysis to assess the impact of NAFLD on the loss of skeletal muscle mass in 52,815 participants who underwent at least two health check-up examinations with BIA.…”

“…Previously, Park et al 5 have shown that the fibrotic burden was increased according to the number of metabolic risk abnormalities and/or diabetes in the participants in the health check-up cohort. Although Song et al 4 has adjusted for several metabolic components, but it would be worthwhile to adjust for the other components of the metabolic risk abnormalities (e.g. waist circumference, triglycerides, high-density lipoprotein) or the presence of metabolic syndrome as a whole.…”

“…2 This leads to the development of "sarcopenia obesity, " characterized by a lean body mass with preserved or increased fat mass. 3 In this issue of Gut and Liver, Song et al 4 investigated the relationship between the sarcopenic obesity status (sarcopenia alone, obesity alone, and sarcopenic obesity) and NAFLD or liver fibrosis in 2,191 participants included in a health check-up program. This study demonstrated that sarcopenic obesity was the risk factor for presence of NAFLD.…”