Influence of duration of obesity on the insulin resistance of obese non-diabetic patients

Abstract

OBJECTIVE: To investigate whether duration of obesity has an independent impact on insulin resistance. DESIGN: Case-control study. SUBJECTS: 30 non-diabetic obese subjects (age, 34 AE 2 y, body mass index (BMI), 33.5 AE 0.8 kg Á m 72 ) with a range (1±35 y) of self-reported duration of obesity, and 12 age-and gender-matched non-obese controls (BMI, 22.1 AE 0.6 kg Á m 72 ). MEASUREMENTS: Oral glucose tolerance (40 g Á m 72 ), insulin sensitivity (by the euglycaemic insulin clamp technique), and insulin secretion (as the product of post-hepatic insulin clearance and plasma insulin concentration). RESULTS: The obese group presented hyperinsulinaemia in the basal state and after glucose loading (insulin area 58 AE 5 vs 33 AE 3 nmol Á l 71 Á 2 h, P 0.005), insulin resistance (M value 37.4 AE 4.8 vs 50.6 AE 2.6 m mmol Á min 71 Á kg FFM 71 , P 0.002), and insulin hypersecretion (61.9 AE 6.0 vs 33.9 AE 4.0 nmol Á 2 h, P 0.007); endogenous glucose production was similar in the two groups. In the whole dataset, insulin resistance was directly related to BMI, the waist-to-hip ratio (WHR), endogenous glucose production, insulin secretion, and fasting serum triglycerides and uric acid concentrations. When the obese subjects were strati®ed by duration of obesity, insulin resistance was progressively lower with longer obesity duration (P 0.04). When simultaneously adjusting by age, gender and BMI, obesity duration was independently associated with greater insulin sensitivity (P 0.003), lower plasma insulin response to oral glucose (P 0.001), and lower fasting and glucose-stimulated insulin release (P 0.01 for both). CONCLUSIONS: In obese subjects with preserved glucose tolerance, duration of obesity is associated with better insulin sensitivity irrespective of the degree of overweight.

Open questions about metabolically normal obesity

“…In contrast with these findings, it has been reported that an early onset of obesity is associated with higher insulin sensitivity. 5,43 No well-defined adaptative mechanisms have been evoked to explain this surprising result, which, differently from the study by Janssens et al, 42 has been obtained in a very small sample (17 subjects in the study by Brochu et al 5 and 30 in the study by Muscelli et al…”

The Effect of Obesity in Adolescence on Adult Health Status

“…Although most studies of obesity duration point to greater cardiovascular risks for those with longer-standing obesity, including higher risks of dyslipidemia, others have found an equivocal 20 or, as suggested by our data, a negative association 21 between obesity in younger years and hyperlipidemia later in life. This finding of a possible protective effect of adolescent obesity on development of high level of LDL cholesterol later in life is enigmatic at present.…”

Serum Uric Acid Predicts Both Current and Future Components of the Metabolic Syndrome

“…19 In a comparison of obese individuals with lean individuals, insulin action was inversely associated with serum UA. 18 A large Italian study also reported a negative correlation between hyperuricemia and insulin action. 17 The relationship between UA and an increased risk for development of T2DM has also been found in larger studies.…”

“…[17][18][19] In one study, serum triglycerides and insulin action together explained 50% of the variation in serum UA level in a group of 37 subjects. 19 In a comparison of obese individuals with lean individuals, insulin action was inversely associated with serum UA.…”