Physical activity support or weight loss counseling for nonalcoholic fatty liver disease?

Abstract

AIM: To determine the clinical effectiveness of intense psychological support to physical activity (PA) in nonalcoholic fatty liver disease (NAFLD), compared with cognitive-behavioral treatment (CBT).

METHODS: Twenty-two NAFLD cases received support to exercise, tailored to their motivational needs (PA group). The effects on body weight, physical fitness [6-min walk test, VO₂max and the PA-rating (PA-R) questionnaire] and body fat (fatty liver indices and visceral adiposity index) were compared with data obtained in 44 NAFLD subjects enrolled in a CBT program for weight loss, after adjustment for propensity score, calculated on baseline data. Measurements were performed at baseline, at 4-mo and one-year follow-up. Changes in anthropometric, biochemical and PA parameters were tested by repeated measurement ANOVA. Outcome results were tested by logistic regression analysis.

RESULTS: At the end of the intensive program, BMI was less significantly reduced in the PA group (-1.09 ± 1.68 kg/m²vs -2.04 ± 1.42 kg/m² in the CBT group, P = 0.019) and the difference was maintained at 1-year follow-up (-0.73 ± 1.63 vs -1.95 ± 1.88, P = 0.012) (ANOVA, P = 0.005). PA-R was similar at baseline, when only 14% of cases in PA and 36% in CBT (P = 0.120) recorded values ≥ 3. At 4 mo, a PA-R ≥ 3 was registered in 91% of PA and 46% of CBT, respectively (P < 0.001) and PA-R ≥ 5 (up to 3 h/wk of moderate-to-heavy intensity physical activity) was registered in 41% of PA and only 9% of CBT group (P < 0.007). The 6-min walk test increased by 139 ± 26 m in PA and by only 43 ± 38 m in CBT (P < 0.001) and VO₂max by 8.2 ± 3.8 mL/kg per minute and 3.3 ± 2.7 mL/kg per minute, respectively (P < 0.002). After adjustment for propensity, weight loss > 7% was significantly associated with CBT group at one year (OR = 6.21; 95%CI: 1.23-31.30), whereas PA-R > 3 was associated with PA group (10.31; 2.02-52.63). Liver enzymes decreased to values within normal limits in 36% of PA cases and 61% of CBT (P < 0.070). Estimated liver fat (Kotronen index) fell below the fatty liver threshold in 36% of PA and 34% and CBT cases at one-year (not different). Also the fatty liver index and the visceral adiposity index improved to a similar extent.

CONCLUSION: Intensive psychological counseling for PA produces hepatic effects not different from standard CBT, improving physical fitness and liver fat independent of weight loss. Strategies promoting exercise are worth and effective in motivated patients, particularly in lean NAFLD patients where large weight loss cannot be systematically pursued.

Keywords: Nonalcoholic fatty liver disease, Behavior treatment, Physical activity, Physical fitness, Weight loss liver fat, Liver enzymes

Core tip: The adherence to healthy diet is usually considered as part of effective treatment by patients with nonalcoholic fatty liver disease (NAFLD), whereas motivation to habitual physical activity is more difficult to pursue. We recently developed a specific psychological support program to regular physical activity to be proposed to NAFLD patients, particularly to those who failed or refused the classical weight loss approach. In a clinical audit, we compared the preliminary results obtained by the physical activity program with the data achieved in a group treated by the standard nutritional counseling, after adjusting for propensity score. The results indicate that physical activity may be implemented in motivated patients, with good results on physical fitness, liver enzymes and liver fat.