Diet and Exercise Interventions Reduce Intrahepatic Fat Content and Improve Insulin Sensitivity in Obese Older Adults

Abstract

Both obesity and aging increase intrahepatic fat (IHF) content, which leads to non-alcoholic fatty liver disease 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. Secondary outcomes included insulin sensitivity (assessed by oral glucose tolerance), body composition (assessed by DXA), physical function (VO 2peak and strength), glucose, lipids, and blood pressure. 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 (r= −0.52; p<0.05). Improvements in VO 2peak, strength, plasma triglyceride and HDL-cholesterol concentration, and diastolic blood pressure 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.

Long-term maintenance of weight loss after lifestyle intervention in frail, obese older adults

“…1;2 There is mounting evidence that obese older adults can successfully lose weight during intensive lifestyle interventions, and weight loss improves health outcomes such as physical function, insulin sensitivity, and coronary heart disease. [3][4][5][6][7][8] Despite these positive findings, the debate remains whether the benefits of weight loss interventions outweigh their risks in older adults. 9;10 The challenge in addressing this question is the lack of long-term follow up studies.…”

Impact of current treatments on liver disease, glucose metabolism and cardiovascular risk in non-alcoholic fatty liver disease (NAFLD): a systematic review and meta-analysis of randomised trials

“…Eight RCTs (373 participants, 39% diabetic; six RCTs with a low risk of bias, four RCTs with post-treatment histology) assessed the effect of lifestyle-or drug-induced weight loss in NAFLD [6][7][8][9][10][11][12][13] (ESM Table 1). …”

Recurrence of non-viral liver disease after orthotopic liver transplantation

“…As such, optimal medical management is imperative so to prevent recurrence of disease. Patients should be encouraged to participate in weight loss and exercise programmes (74)(75)(76)(77)(78).…”