Association between Cardiorespiratory Fitness, Relative Grip Strength with Non-Alcoholic Fatty Liver Disease.

BACKGROUND Non-alcoholic fatty liver disease (NAFLD) is a common clinical syndrome with no medications for long-term management. At present, diet control and weight loss are 2 major lifestyle components to reduce the risk of NAFLD. However, other lifestyle components such as cardiorespiratory fitness (CRF) and grip strength (GS) have been neglected in research. This study was to investigate the correlation between CRF, relative GS (RGS), and NAFLD among a male study population. MATERIAL AND METHODS We screened 1126 men who underwent comprehensive health checks. The participants were divided into an NAFLD group (n=224) and a non-NAFLD group (n=902). The clinical data analyzed included anthropometry, biochemical examination, CRF measurement, and GS calculation were recorded, and the dose-response association between maximal oxygen uptake (VO₂max), RGS, and NAFLD. Stepwise logistic regression analysis was conducted to establish a predictive model of NAFLD. RESULTS VO₂max <30 mL/kg⁻¹·min⁻¹ was not associated with the risk of NAFLD (P>0.05). When VO₂max was >30 mL/kg⁻¹·min⁻¹, the risk of NAFLD decreased obviously (P=0.007), suggesting a dose-response relationship between VO₂max and NAFLD risk. With the increase of RGS, the risk of NAFLD decreased prominently (P<0.001), which indicated a dose-response relationship between RGS and NAFLD risk. We also found that body fat percentage, body mass index, systolic blood pressure, diastolic blood pressure, total cholesterol and triglycerides were risk factors, whereas VO₂max >30 mL/kg⁻¹·min⁻¹, RGS, and high-density lipoprotein cholesterol were protective factors for NAFLD. The area under the curve (AUC) of the predictive model of NAFLD was 0.819 (95% confidence interval [CI]: 0.790-0.847, P=0.174). The sensitivity and specificity were 80.4% and 67.8%, respectively. CONCLUSIONS In the male study population, VO₂max and RGS were negatively correlated with the risk of NAFLD, thus, the risk of NAFLD could thus be reduced by improving VO₂max and RGS in this population.