Table 2.
Published study findings for the relationship between physical activity and nonalcoholic fatty liver disease (2010-2015)
| Ref. | Population | Type of activity | Weight loss | Insulin resistance | Inflammation and | Liver | Liver fat | Liver | Conclusions |
| intervention | (% Δ) | and lipids | oxidative stress | enzymes | by imaging | histology | |||
| Hallsworth et al[26] | NAFLD | Activity monitor | NA | NA | NA | NA | NA | NA | NAFLD = more sedentary time, less energy expenditure, and greater prevalence of DM than healthy controls |
| Gerber et al[14] | NAFLD, NAFLD + DM | Activity monitor | NA | NA | NA | NA | NA | NA | NAFLD = less PA time than non-NAFLD NAFLD + DM = lowest quartile of average PA as well as moderate-vigorous PA |
| Oh et al[33] | NAFLD | Acceleration | -1.9% | NA | ↓ TNF-α, IL-6, leptin, IMCL ↑ adiponectin | Improved | Improved (US) | NA | Acceleration training results in significant improvement in IR, inflammation, liver enzymes, steatosis and quality of life |
| Kawaguchi et al[32] | NAFLD | Hybrid | -0.9% | ↓ Insulin HOMA-IR | ↓ IL-6 | Improved | Improved (US) | NA | Hybrid training results in significant improvement in IR, inflammation, liver enzymes and steatosis |
| Kistler et al[34] | NASH, NAFLD | None (self-report) | NA | ↓ Insulin and glucose (vigorous PA vs inactive) | No effect | No effect | NA | Vigorous PA = ↓ odds of NASH and fibrosis | Vigorous but not moderate or total exercise is associated with the severity of NAFLD |
| Haus et al[36] | NAFLD | Aerobic | 0 | ↓ Glucose HOMA-IR | ↑ Lipid PUI, adiponectin | NA | NA | Improved steatosis | Short-term aerobic exercise favorably alters hepatic lipid composition by increasing polyunsaturated lipids |
| Promrat et al[38] | NASH | Aerobic | -9.3% | ↓ Glucose, insulin, HbA1C HOMA-IR (NS) | NA | Improved | NA | Improved NAS. No change in fibrosis | > 7% weight loss resulted in improvement in overall NAS, ballooning, steatosis, inflammation |
| Pugh et al[39] | NAFLD | Aerobic | 0 | No effect | No effect | Improved | No effect | NA | Aerobic exercise improves NO-mediated vasodilation in NAFLD |
| Pugh et al[40] | NAFLD | Aerobic | 0 | ↓ Glucose | No effect | No effect | No effect | NA | Aerobic exercise improves flow mediated dilation in NAFLD |
| Sullivan et al[27] | NAFLD | Aerobic | 0 | No effect | No effect | Improved | Improved (H-MRS) | NA | Aerobic exercise without weight loss results in significant reduction in intrahepatic triglyceride content |
| Jin et al[23] | NAFLD | Aerobic | -3.9% | ↓ Total cholesterol | NA | Improved | NA | Improved steatosis | Aerobic exercise results in decreased steatosis among living donors even in the absence of significant weight loss |
| Oh et al[28] | NAFLD | Aerobic | -13.3% | ↓ HbA1C HOMA-IR, LDL, TG ↑ insulin, HDL | ↓ TNF-α, IL-6, leptin, hsCRP, ferritin, TBARS ↑ adiponectin | Improved | Improved (US and Fibroscan) | NA | Diet with exercise exceeds diet alone in reducing steatosis, inflammation, insulin resistance |
| Sun et al[24] | NAFLD | Aerobic | -11.6% | ↓ HOMA-IR, total cholesterol | No effect | Improved | NA | NA | Aerobic exercise results in decrease in ALT, insulin resistance, and the metabolic syndrome |
| Zelber-Sagi et al[30] | NAFLD | Resistance | -0.75% | ↓ Total cholesterol | ↓ Ferritin | No effect | Improved (US) | NA | Resistance exercise results in reduction in steatosis, abdominal adiposity, inflammation, cholesterol |
| Hallsworth et al[29] | NAFLD | Resistance | 0 | ↓ HOMA-IR (NS) | ↑ Fat oxidation | No effect | Improved (H-MRS) | NA | Resistance exercise results in a 13% relative reduction in intrahepatic lipids |
| Bacchi et al[43] | NAFLD + DM | Resistance vs aerobic | No | ↓ HDL, TG, HbA1c ↑ clamp-measured insulin sensitivity | No effect | No effect | Improved (MRI) | NA | Both resistance and aerobic exercise result in improved steatosis, abdominal, and visceral fat content |
| Eckard et al[21] | NAFLD, NASH (88%) | Resistance and aerobic | -1.3%1 | No effect | No effect | Improved | NA | Improved NAS in all groups | Lifestyle modification, even without weight loss, improves NAS |
| Oh et al[35] | NAFLD | Aerobic | 10.4%2 | ↓ HOMA-IR, LDL, TG ↑ HDL | ↓ TNF-α, IL-6, leptin, hsCRP, ferritin, TBARS ↑ adiponectin | Improved | Improved (US, fibroscan) | NA | Moderate to vigorous PA (> 250 min weekly) significantly reduces markers of IR, oxidative stress and fatty acid metabolism independent of weight reduction |
Weight lost in the diet plus exercise arms, mild weight gain was seen in the moderate exercise alone arm;
Average weight lost across all groups (range 6.4%-12.4%). ALT: Alanine aminotransferase; DM: Diabetes mellitus; H-MRS: Hydrogen-magnetic resonance spectroscopy; HbA1C: Glycosylated hemoglobin; HDL: High-density lipoprotein cholesterol; HOMA-IR: Insulin resistance by homeostasis model assessment; hsCRP: High sensitivity c-reactive protein; IL-6: Interleukin-6; IMCL: Intramyocellular lipids; LDL: Low-density lipoprotein cholesterol; NA: Not assessed; NAFLD: Nonalcoholic fatty liver disease; NASH: Nonalcoholic steatohepatitis; NO: Nitric oxide; NS: Not statistically significant; PA: Physical activity; PUI: Lipid polyunsaturated index; TBARS: Thiobarbituric acid reactive substances; TG: Triglycerides; TNF-α: Tumor necrosis factor alpha; US: Ultrasound.