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Diet and Exercise Interventions Reduce Intrahepatic Fat Content and Improve Insulin Sensitivity in Obese Older Adults
Author(s) -
Shah Krupa,
Stufflebam Abby,
Hilton Tiffany N.,
Sinacore David R.,
Klein Samuel,
Villareal Dennis T.
Publication year - 2009
Publication title -
obesity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.438
H-Index - 199
eISSN - 1930-739X
pISSN - 1930-7381
DOI - 10.1038/oby.2009.126
Subject(s) - medicine , endocrinology , insulin resistance , triglyceride , insulin , body mass index , obesity , nonalcoholic fatty liver disease , blood pressure , insulin sensitivity , cholesterol , fatty liver , disease
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 ≥30 kg/m 2 ) older (≥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 2peak 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 2peak , 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.