F-35 Free Communication/Poster - Nutrition and Chronic Disease Friday, June 3, 2016, 1:00 PM - 6:00 PM Room: Exhibit Hall A/B
Exercise training is commonly prescribed for individuals diagnosed with nonalcoholic fatty liver disease (NAFLD); however, consensus is lacking regarding the volume and intensity of exercise for optimal benefits.
PURPOSE: Here, we sought to determine if high intensity interval exercise (HIIE) differentially impacted intrahepatic lipid (IHL) content and hepatic inflammatory biomarkers compared with continuous moderate exercise (CME) in obese adults with hepatic steatosis.
METHODS: Sixteen obese adults (BMI, 37.0±1.4 kg/m2; age, 43.7±3.0 yr; IHL, 16.9±2.3%) were randomized to either 4 wk x 4x/wk of HIIE (4 min 80% VO2peak/3 min 50% VO2peak) or CME (55% VO2peak, 50-75 min), matched for energy expenditure (~400 kcal/session). Baseline and post-training IHL were measured by 1H-MRS and frequent blood samples were analyzed for glucose, insulin, c-peptide, fetuin A, cytokeratin 18 (CK18), and NEFA levels during a meal test (180 min) as incremental area under curve (iAUC).
RESULTS: Baseline IHL and fasting glucose concentrations were greater in CME and HIIE compared to controls (P0.05). Body weight, body mass index, fat mass and fasting insulin concentrations were greater in CME vs HIIE (P<0.05); whereas, HIIE had greater VO2peak and insulin sensitivity (P0.05). Both HIIE and CME lowered IHL [HIIE, -37.0±12.4%; CME, -20.1±6.6%, P<0.05], with no differences noted between exercise intensities (P=0.40). Fetuin A and CK18 levels were not different between CME and HIIE, however, CK18 tended to decrease in the HIIE group (P=0.09). Exercise training decreased postprandial insulin, c-peptide levels, and insulin secretion rate (iAUC, P<0.05), yet no between group differences in CME vs HIIE were observed. Baseline postprandial insulin clearance and c-peptide iAUC were predictors of the ΔIHL after controlling for body mass, fat mass, percent body fat, and fasting/postprandial glucose, insulin, and NEFA levels.
CONCLUSIONS: Four weeks of both high intensity interval and moderate intensity continuous exercise training effectively lowered IHL content in sedentary obese individuals with hepatic steatosis. Larger cohort studies examining different exercise intensities and durations are warranted.