Long-term effect of exercise on improving fatty liver and cardiovascular risk factors in obese adults: A 1-year follow-up study.

Exercise training can reduce hepatic fat accumulation and cardiovascular risk among patients with non-alcoholic fatty liver disease (NAFLD), but how long these benefits extend beyond the period of active intervention is unclear. Intrahepatic triglyceride (IHTG) content, measured by proton magnetic resonance spectroscopy, and metabolic risk factors among 220 obese people with NAFLD, who were randomly assigned to vigorous/moderate exercise, moderate exercise or no exercise (control), were assessed at 1 year after the 12-month exercise intervention. IHTG content was significantly reduced in the 2 exercise groups compared with the control group over the 12-month active intervention. It was significantly lower (by -2.39%) in the vigorous/moderate exercise group compared with the control group at the 1-year follow-up (95% confidence interval -4.72 to -0.05%; P = .045). Waist circumference and blood pressure remained significantly lower in the vigorous/moderate exercise group and the moderate exercise group compared with the control group at the 1-year follow-up. Visceral adipose fat remained significantly reduced, but with no differences among 3 groups. These findings suggest 12-month exercise intervention induced reductions in hepatic fat accumulation, abdominal obesity and blood pressure for up to 1 year after the active intervention, with some attenuation of the benefits.

Serum alanine aminotransferase independently correlates with intrahepatic triglyceride contents in obese subjects.

BACKGROUND AND AIM: Liver enzymes including serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT) are well recognized as surrogate makers reflecting non-alcoholic fatty liver disease (NAFLD). However, the associations of serum ALT, AST and GGT with hepatic lipid contents are not well established. The aim of this study was to investigate the relationship between liver enzymes and intrahepatic triglyceride (IHTG) contents, and explore the feasibility in using liver enzymes to reflect accumulation of IHTG in obese subjects. METHODS: A cross-sectional analysis was conducted in 475 obese adults aged 40-65 years. Anthropometric parameters and blood biochemical indexes including liver enzymes, glucose and lipid profiles were measured. The liver triglyceride contents of subjects were determined by (1)H-MRS. RESULTS: Serum ALT, AST and GGT were positively correlated with IHTG contents (p < 0.01). Serum ALT, AST and GGT levels at the highest quartile of IHTG contents were significantly elevated as compared with those in the lowest quartile (p < 0.01). Multivariate linear regression analysis demonstrated that serum ALT, but not AST or GGT was independently associated with IHTG contents. By logistic regression analysis, the odds ratio for higher IHTG contents was increased by 1.464 times/1 SD increase in serum ALT level after adjusting for multiple confounding factors [OR (95% CI) 2.464 (1.584-3.834)]. However, these relationships could not be observed between serum AST or GGT with IHTG contents. CONCLUSIONS: Serum ALT level is independently correlated with the hepatic triglyceride contents in obese subjects and more appropriate to be used as a predictor for the degree of NAFLD rather than AST and GGT.

Intrahepatic triglyceride content is independently associated with chronic kidney disease in obese adults: A cross-sectional study.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) are associated with some common critical cardio-metabolic risk factors. The aim of this study was to explore the association between intrahepatic triglyceride (IHTG) content and CKD in obese subjects. METHODS: A total of 1068 obese participants received anthropometric, biochemical measurements and hepatic ultrasonography. Of those, 485 participants received magnetic resonance spectroscopy ((1)H-MRS) for the determination of IHTG content. CKD was defined as a urinary albumin:creatinine ratio (UACR)≥30 mg/g and/or estimated glomerular filtration rate (eGFR)<60 mL/min per 1.73 m(2). RESULTS: The prevalence of CKD was significantly higher in NAFLD subjects compared to subjects without NAFLD, while the prevalence of CKD was gradually increased as the IHTG content increased by quartiles (P for trend<0.001). After adjustment for multivariate metabolic factors, the risk of abnormal albuminuria and CKD was increased by 68% [OR (95% CI): 1.68 (1.21-2.33), P<0.01] and 54% [OR (95% CI): 1.54 (1.14-2.07), P<0.01] respectively per one standard deviation (SD) increase in IHTG content. The association between IHTG content and CKD was not changed by conventional risk factors, including age, BMI and hypertension (all P<0.05). CONCLUSION: IHTG content is independently associated with CKD in obese adults.