title: Weight loss reduces abdominal fat and improves insulin action in middle-aged and older men with impaired glucose tolerance.
abstract: Aging is associated with an increased accumulation of abdominal fat, glucose intolerance, and insulin resistance. We tested the hypothesis that diet-induced weight loss would reduce the abdominal distribution of fat and improve glucose tolerance and insulin action in a group of obese middle-aged and older men with normal or impaired glucose tolerance (IGT). Oral glucose tolerance tests (OGTTs) were performed at baseline and after 9 months of diet-induced weight loss in 35 men (mean age, 60 +/- 8 years). Fifteen men of comparable age and degree of obesity who did not participate in the weight loss intervention served as controls. Subjects lost 9.0 +/- 2.0 kg (mean +/- SD) body weight (P < .001), resulting in a 19% reduction in percent body fat (30.0 +/- 4.0% to 24.0% +/- 4.0%, P < .001), an 8% reduction in waist circumference (104.0 +/- 7.0 to 96.0 +/- 7.0 cm, P < .001), and a 2% reduction in waist to hip ratio [WHR] (0.97 +/- 0.06 to 0.95 +/- 0.06, P < .01). Weight loss improved glucose tolerance: nine men with IGT at baseline reverted to normal glucose tolerance following the intervention. Glucose area during the OGTT was significantly reduced after weight loss (-22.0%, P < .001), while it increased in control subjects (+32%, P < .004). In multiple regression analysis, the improvement in glucose area following weight loss in these 35 men was attributed to the reduction in waist circumference (P < .01) and baseline glucose area (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000005:Abdomen; D000273:Adipose Tissue / Q000378:metabolism*; D000368:Aged; D000375:Aging / Q000378:metabolism / Q000502:physiology; D001786:Blood Glucose / Q000032:analysis; D001823:Body Composition / Q000502:physiology*; D001824:Body Constitution; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000503:physiopathology; D005947:Glucose / Q000378:metabolism* / Q000494:pharmacology; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood / Q000494:pharmacology*; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015431:Weight Loss / Q000502:physiology*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D005947:Glucose