In a clinical trial, patients with nonalcoholic fatty liver disease who underwent resistance training had improved hepatic fat over time, indicating this type of exercise could be used as a complement to treating the disease, according to study data.
Researchers randomly assigned 82 patients with NAFLD to undergo 40 minutes of resistance training (RT; n = 44) three times a week or home stretching (n = 38) for 3 months. RT included leg press, chest press, seated rowing, latissimus pull down etc. with 8 to 12 repetitions and 3 sets for each exercise. Overall, 36 patients in the RT group and 33 in the stretching group completed the 3 month follow-up period and were included in the final analysis.
“[We assessed] hepatic ultrasound, fasting blood tests, anthropometrics and body composition by dual energy X-ray absorptiometry,” the researchers wrote. “At baseline and follow-up, patients filled out a detailed semi-quantitative food frequency questionnaire reporting their habitual nutritional intake. [In addition], steatosis was quantified by the hepatorenal-ultrasound index representing the ratio between the brightness level of the liver and the right kidney.”
Analyses showed hepatorenal ultrasound index (HRI) score was greatly reduced in the RT group compared with the stretching group (– 0.25 ± 0.37 vs. – 0.05 ± 0.28; P = .017). The patients in the RT group had an overall greater reduction in total, trunk and android fat with increase in lean body mass.
No correlation between the reduction in HRI in the RT group and weight change during the study was found, according to the research, but the reduction was positively correlated with the change in trunk fat (r = 0.37, P = .048). In contrast, the change in HRI among patients in the stretching group was positively correlated with weight change (r = 0.35, P = .055) and BMI change (r = 0.36, P = .049).
Patients in the RT group had reduced serum ferritin level and total cholesterol. No differences between the groups in terms of dietary changes were observed during the study in total calories, carbohydrates, protein, fat and different types of fat (P ≥ .114 for all comparisons). No correlation between the reduction in HRI in the RT group and change in dietary intake of total calories and different dietary components was observed (P ≥ .42 for all correlations).
There were also no significant differences in reduction of liver enzymes between the groups. RT had no influence on serum glucose, insulin, glycosylated hemoglobin and triglycerides, according to the research.
“This relatively large randomized clinical trial demonstrated a significant reduction in steatosis, as assessed by HRI, during 3 months RT accompanied by favorable changes in body composition and reduction of serum ferritin,” the researchers concluded. – by Melinda Stevens