Effect of orlistat on periostin, adiponectin, inflammatory markers and ultrasound grades of fatty liver in obese NAFLD patients

Orlistat is recommended in the treatment of obesity, which is an independent risk factor for nonalcoholic fatty liver disease (NAFLD). The reported findings of orlistat in NAFLD are divisive. Recently, periostin is identified as an important regulatory molecule in the pathogenesis of obesity-induced fatty liver. Therefore, this study aimed to evaluate the potential effects of orlistat in the treatment of NAFLD. A 16-week prospective observational study was conducted, with obese NAFLD patient (n=77) receiving orlistat (120 mg capsules, three times a day) with hypocaloric diet or hypocaloric diet only. Grades of fatty liver were determined using ultrasound (US) echogenicity of liver; serum levels of periostin, adiponectin, tumor necrosis factor (TNF)-α and interleukin-6 were determined using ELISA kits at 0 and 16 weeks. Correlations of US grades of fatty liver with these biomarkers were also determined. Orlistat significantly reversed the US grades of fatty liver (P=0.016), decreased serum levels of periostin (P=0.030) and TNF-α (P=0.040), and increased serum adiponectin levels (P<0.001) when compared with hypocaloric diet only. Serum interleukin-6 levels were not found to be significantly different in both groups after the treatment. In the orlistat group, the degree of reduction in grades of fatty liver was found to be positively correlated with the changes in serum levels of periostin (r(s)=0.306, P=0.041) and adiponectin (r(s)=0.314, P=0.036), whereas the associations were insignificant with the change in serum levels of TNF-α (r(s)=0.053, P=0.729). Mild gastrointestinal side effects (20%) were reported in the orlistat group. In conclusion, orlistat is effective in the treatment of NAFLD patients without fibrosis. This study demonstrated a positive association between the reduction of fatty infiltration in the liver and the changes in serum levels of periostin and adiponectin in obese NAFLD patients.