Exercise-induced reversal of insulin resistance in obese elderly is associated with reduced visceral fat

Abstract

Exercise improves glucose metabolism and delays the onset and/or reverses insulin resistance in the elderly by an unknown mechanism. In the present study, we examined the effects of exercise training on glucose metabolism, abdominal adiposity, and adipocytokines in obese elderly. Sixteen obese men and women (age = 63 +/- 1 yr, body mass index = 33.2 +/- 1.4 kg/m2) participated in a 12-wk supervised exercise program (5 days/wk, 60 min/day, treadmill/cycle ergometry at 85% of heart rate maximum). Visceral fat (VF), subcutaneous fat, and total abdominal fat were measured by computed tomography. Fat mass and fat-free mass were assessed by hydrostatic weighing. An oral glucose tolerance test was used to determine changes in insulin resistance. Exercise training increased maximal oxygen consumption (21.3 +/- 0.8 vs. 24.3 +/- 1.0 ml.kg(-1).min(-1), P < 0.0001), decreased body weight (P < 0.0001) and fat mass (P < 0.001), while fat-free mass was not altered (P > 0.05). VF (176 +/- 20 vs. 136 +/- 17 cm2, P < 0.0001), subcutaneous fat (351 +/- 34 vs. 305 +/- 28 cm2, P < 0.03), and total abdominal fat (525 +/- 40 vs. 443 +/- 34 cm2, P < 0.003) were reduced through training. Circulating leptin was lower (P < 0.003) after training, but total adiponectin and tumor necrosis factor-alpha remained unchanged. Insulin resistance was reversed by exercise (40.1 +/- 7.7 vs. 27.6 +/- 5.6 units, P < 0.01) and correlated with changes in VF (r = 0.66, P < 0.01) and maximal oxygen consumption (r = -0.48, P < 0.05) but not adipocytokines. VF loss after aerobic exercise training improves glucose metabolism and is associated with the reversal of insulin resistance in older obese men and women.

Exercise-induced adaptations to white and brown adipose tissue

“…Several studies have investigated the effect of exercise on adiponectin concentration in humans. Although some studies found that the concentration of circulating adiponectin increased after exercise (Lim et al, 2008;Kondo et al, 2006), in other studies, the concentration of circulating adiponectin was unchanged after exercise (Jürimäe et al, 2007;O'Leary et al, 2006;Klimcakova et al, 2006;Nassis et al, 2005;Hara et al, 2005). Likewise, some studies have reported that the concentration of circulating adiponectin in healthy and diabetic rodents increased after exercise (Zeng et al, 2007;Lee et al, 2011), whereas in other studies, the concentration of circulating adiponectin in healthy rodents was unchanged after exercise (Lee et al, 2011;Bhattacharya et al, 2005;Huang et al, 2007).…”

Influence of Exercise Intensity on Abdominal Fat and Adiponectin in Elderly Adults

“…et al demonstrated an exercise training-induced reduction in visceral fat, 9 abdominal subcutaneous fat, and total abdominal fat. In these studies, the volunteers exercised at ~70% of VO 2max , 5 days of week for 50-60 minutes and lost ~7 pounds over the course of the study.…”

“…8 In addition, O'Leary et al demonstrated a relationship between exercise training-induced reductions in visceral fat and improvements in glucose metabolism. 9 However, the optimal intensity of exercise necessary to promote the reduction of visceral fat has not been evaluated in elderly, obese adults.…”

β-Cell Dysfunction Is Associated with Metabolic Syndrome Severity in Adults

“…Total fat and fat free mass were measured using the intelligence dual X-ray absorptiometry system (iDXA; Lunar Prodigy, Madison, WI), and visceral adipose tissue mass was determined using computerized tomography (CT) as previously described. 15 In brief, subjects were placed in a supine position, and measurements were made at 120 kV with a slice thickness of 8 mm. Images were obtained manually without contrast at the fourth lumbar vertebra (L 4 ).…”