Moderate-intensity aerobic training and resistance training with dietary modification are equally effective for reducing intrahepatic fat and improving underlying insulin resistance in patients with nonalcoholic fatty liver disease (NAFLD), researchers reported in Clinical and Translational Gastroenterology.
All patients with NAFLD were medical personnel and were randomly assigned (1:1) to 12 weeks of a supervised training program of moderate-intensity aerobic or resistance exercise with dietary intervention that included monthly nutritional counseling by a dietician. The analysis included 18 participants in the aerobic group (mean age, 37.4 ± 1.9 years; 13 women; mean body mass index [BMI], 26.8 ± 0.7 kg/m2) and 17 in the resistance group (mean age, 38.2 ± 2.2 years; 14 women; mean BMI, 27.3 ± 0.9 kg/m2).
Aerobic group participants completed an average of 3.35 ± 0.30 exercise sessions per week, and the resistance group completed 3.39 ± 0.28 sessions per week. The 2 exercise regimens resulted in significant and similar reductions in liver fat content. The mean relative reduction from baseline to study completion was –10.3% (95% CI, –18.2 to –2.40) in the aerobic group and –12.6% (–20.5 to –4.69) in the resistance group.
Hepatic steatosis, which was defined as controlled attenuation parameter (CAP) >248 dB/m, was not present in 9 participants (50%) in the aerobic group and in 9 participants (53%) in the resistance group (P =.862) at the end of the training period.
Aerobic group participants had a mean relative reduction in body weight from baseline of –4.8% (95% CI, –7.4 to –2.1), and resistance group members had a reduction of –4.2% (–6.9 to –1.5). The 2 groups showed significant improvement in the homeostatic model assessment of insulin resistance, the muscle insulin sensitivity index (MISI), and the homeostasis model assessment of beta-cell function from baseline to week 12 (P <.05).
Univariate correlation analysis in all participants showed that the absolute reduction in hepatic fat content after training was positively associated with changes in body weight (r = 0.51; P =.002), waist circumference (r = 0.48; P =.004), body fat mass (r = 0.52; P =.001), visceral fat rating (r = 0.61; P <.001), and muscle mass (r = 0.42; P =.012), but was inversely associated with MISI changes (r = –0.45; P =.007).
The investigators also found a significant association between the number of exercise sessions per week and the absolute reduction in hepatic fat content (r = 0.52; P =.001). At the end of the training period, hepatic steatosis was no longer present in 15 of 21 participants (71%) who exercised ≥3 times weekly and in 3 of 14 participants (21%) who exercised <3 times weekly (P =.004).
This study has some limitations, according to the researchers, as they quantified intrahepatic fat with an elastographic technique instead of a magnetic resonance-based one. Additionally, all participants were medical personnel who may be highly motivated to participate in the exercise program, and only 35 patients were included in the analysis in total.
“Diet and exercise prescriptions for NAFLD should be tailored to a patient’s preference, physical fitness, and comorbidities to facilitate sustained adherence to lifestyle changes,” the study authors advised.
Charatcharoenwitthaya P, Kuljiratitikal K, Aksornchanya O, et al. Moderate-intensity aerobic vs resistance exercise and dietary modification in patients with nonalcoholic fatty liver disease: a randomized clinical trial. Clin Transl Gastroenterol. 2021;12(3):e00316. doi: 10.14309/ctg.0000000000000316