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/m(2) vs -2.04 ± 1.42 kg/m(2) 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: Behavior treatment; Liver enzymes; Nonalcoholic fatty liver disease; Physical activity; Physical fitness; Weight loss liver fat.

Figure 1

Anthropometric and liver enzyme levels at baseline and follow-up in subjects treated either by intensive psychological counseling on physical activity (open bars) or by cognitive-behavior treatment for weight loss (closed bars). A: Body mass index (BMI); B: Waist circumference; C: Alanine aminotransferase (ALT) levels. Data are presented as mean and 95%CI.

Figure 2

Physical fitness and quantitative physical activity at baseline and follow-up in subjects treated either by the intensive psychological counseling on physical activity (open bars) or the classical cognitive-behavior treatment for weight loss (closed bars). A: Maximum oxygen consumption at runrace; B: Distance at 6-min walk test; C: Physical Activity-Rating (PA-R) questionnaire. Data are presented as mean and 95%CI.

Figure 3

Indices of liver and visceral adiposity at baseline and follow-up in subjects treated either by the intensive psychological counseling on physical activity (open bars) or the classical cognitive-behavior treatment for weight loss (closed bars). A: Kotronen Index; B: Fatty liver index; C: Visceral adiposity index. Data are presented as mean and 95%CI.