Fitness, adiposopathy, and adiposity are independent predictors of insulin sensitivity in middle-aged men without diabetes.

Adiposopathy, or sick fat, refers to adipose tissue dysfunction that can lead to several complications such as dyslipidemia, insulin resistance, and hyperglycemia. The relative contribution of adiposopathy in predicting insulin resistance remains unclear. We investigated the relationship between adiposopathy, as assessed as a low plasma adiponectin/leptin ratio, with anthropometry, body composition (hydrostatic weighing), insulin sensitivity (hyperinsulinemic-euglycemic clamp), inflammation, and fitness level (ergocycle VO2max, mL/kgFFM/min) in 53 men (aged 34-53 years) from four groups: sedentary controls without obesity (body mass index [BMI] <25 kg/m(2)), sedentary with obesity (BMI > 30 kg/m(2)), sedentary with obesity and glucose intolerance, and endurance trained active without obesity. The adiponectin/leptin ratio was the highest in trained men (4.75 ± 0.82) and the lowest in glucose intolerant subjects with obesity (0.27 ± 0.06; ANOVA p < 0.0001) indicating increased adiposopathy in those with obesity. The ratio was negatively associated with adiposity (e.g., waist circumference, r = -0.59, p < 0.01) and positively associated with VO2max (r = 0.67, p < 0.01) and insulin sensitivity (M/I, r = 0.73, p < 0.01). Multiple regression analysis revealed fitness as the strongest independent predictor of insulin sensitivity (partial R (2) = 0.61). While adiposopathy was also an independent and significant contributor (partial R (2) = 0.10), waist circumference added little power to the model (partial R (2) = 0.024). All three variables remained significant independent predictors when trained subjects were excluded from the model. Plasma lipids were not retained in the model. We conclude that low fitness, adiposopathy, as well as adiposity (and in particular abdominal obesity) are independent contributors to insulin resistance in men without diabetes.

Mid-thigh subcutaneous adipose tissue and glucose tolerance in the Quebec family study.

OBJECTIVE: To clarify the relationship between the amount of mid-thigh subcutaneous adipose tissue (SCAT) and glucose tolerance in men and women. METHODS: Midthigh and abdominal computed tomography (CT) scans were obtained from 63 men and 110 women from the Quebec Family Study. Areas and attenuations of adipose tissue compartments and skeletal muscle measured from CT scans were related to glycemia and insulinemia values from an oral glucose tolerance test (OGTT). RESULTS: Adjusted for age and fat mass or age and percent fat, negative relationships (all p < 0.05) between the surface area of mid-thigh SCAT and OGTT data (glucose and insulin area under the curve, glycemia and insulin at 120 min) were seen in men (r range -0.22 to -0.37) and women (r range -0.20 to -0.30). Similar but weaker tendencies were observed when correcting for visceral adiposity. Correlations of OGTT variables with ratios of midthigh SCAT to abdominal visceral adipose tissue and to fat mass revealed significant negative relationships in both genders. Tertile analyses showed better glucose handling in subjects with a higher content of mid-thigh SCAT. CONCLUSION: These data suggest that the preferential deposition of adipose tissue as mid-thigh SCAT is a strategy to prevent glucose intolerance.