Diet and exercise interventions reduce intrahepatic fat content and improve insulin sensitivity in obese older adults.

Journal Article

Both obesity and aging increase intrahepatic fat (IHF) content, which leads to nonalcoholic fatty liver disease (NAFLD) and metabolic abnormalities such as insulin resistance. We evaluated the effects of diet and diet in conjunction with exercise on IHF content and associated metabolic abnormalities in obese older adults. Eighteen obese (BMI >or=30 kg/m(2)) older (>or=65 years old) adults completed a 6-month clinical trial. Participants were randomized to diet (D group; n = 9) or diet + exercise (D+E group; n = 9). Primary outcome was IHF quantified by magnetic resonance spectroscopy (MRS). Secondary outcomes included insulin sensitivity (assessed by oral glucose tolerance), body composition (assessed by dual-energy X-ray absorptiometry), physical function (VO(2 peak) and strength), glucose, lipids, and blood pressure (BP). Body weight (D: -9 +/- 1%, D+E: -10 +/- 2%, both P < 0.05) and fat mass (D: -13 +/- 3%, D+E -16 +/- 3%, both P < 0.05) decreased in both groups but there was no difference between groups. IHF decreased to a similar extent in both groups (D: -46 +/- 11%, D+E: -45 +/- 8%, both P < 0.05), which was accompanied by comparable improvements in insulin sensitivity (D: 66 +/- 25%, D+E: 68 +/- 28%, both P < 0.05). The relative decreases in IHF correlated directly with relative increases in insulin sensitivity index (ISI) (r = -0.52; P < 0.05). Improvements in VO(2 peak), strength, plasma triglyceride (TG), and low-density lipoprotein-cholesterol concentration, and diastolic BP occurred in the D+E group (all P < 0.05) but not in the D group. Diet with or without exercise results in significant decreases in IHF content accompanied by considerable improvements in insulin sensitivity in obese older adults. The addition of exercise to diet therapy improves physical function and other obesity- and aging-related metabolic abnormalities.

Full Text

Duke Authors

Cited Authors

  • Shah, K; Stufflebam, A; Hilton, TN; Sinacore, DR; Klein, S; Villareal, DT

Published Date

  • December 2009

Published In

Volume / Issue

  • 17 / 12

Start / End Page

  • 2162 - 2168

PubMed ID

  • 19390517

Electronic International Standard Serial Number (EISSN)

  • 1930-739X

International Standard Serial Number (ISSN)

  • 1930-7381

Digital Object Identifier (DOI)

  • 10.1038/oby.2009.126

Language

  • eng