Insulin Sensitivity In Young Men Research Articles

Family history of hypertension and serum triglycerides predict future insulin sensitivity: a 17-year follow-up study of young men.

Low insulin sensitivity is closely related to both cardiovascular diseases and diabetes development. Still, correlates of insulin sensitivity have mainly been examined in cross-sectional studies. As far as we are aware, the longitudinal stability of insulin sensitivity in young men is largely unknown. We aimed for the first time to examine both the stability (tracking) and longitudinal predictors of future insulin sensitivity in healthy young men with and without a family history of diabetes or hypertension. We performed a 17-year follow-up study of a cohort of 100 healthy young men. Cardiovascular risk markers, including insulin sensitivity measured by the gold standard method--hyperinsulinaemic isoglycaemic glucose clamp--were examined both at baseline and at follow-up. Baseline insulin sensitivity showed no significant correlation with insulin sensitivity at follow-up, whereas all other measured cardiovascular risk markers had significant correlation (tracking coefficients 0.4-0.7). In multiple regression analyses, family history of hypertension and baseline triglycerides remained the negative predictors of future insulin sensitivity. This was driven by the strong correlations in men with family history of diabetes. Our data suggest that clamp-derived insulin sensitivity is not a stable feature in young men, and that family history of hypertension and baseline triglycerides were associated with future insulin sensitivity, especially in men with a family history of diabetes, and irrespective of blood pressure status 17 years earlier. These findings provide further insight into the development of insulin sensitivity and related diseases.

Testosterone concentration and insulin sensitivity in young men with type 1 and type 2 diabetes.

Reduced testosterone, a recognized comorbidity of reduced insulin sensitivity (IS) and type 2 diabetes (T2D), has also been reported in adult males with type 1 diabetes (T1D). However, there are limited data on how early reduced testosterone occurs, and whether it is related to the reduced IS in T1D. Leptin, a modulator of the HPG-axis, may also influence testosterone in T1D. We hypothesized that IS and leptin would be associated with total testosterone (TT), and free androgen index (FAI) in adolescent males with T1D. T1D (n = 35), T2D (n = 13), lean (n = 13) and obese (n = 9) adolescent males had IS measured by hyperinsulinemic-euglycemic clamps (glucose infusion rate [GIR]), in addition to leptin, sex hormone binding globulin (SHBG), TT, and FAI. The cohort was stratified into those with T1D (n = 35) and those without (n = 35). TT and SHBG were lower in T2D boys vs. lean controls, and GIR and leptin correlated with FAI and TT in non-T1D participants. However, despite being insulin resistant, adolescent males with T1D had normal TT and FAI, unrelated to GIR. In T1D, leptin was inversely associated with TT (p = 0.005) and FAI (p = 0.01), independent of puberty, hemoglobin A1c (HbA1c), diabetes duration, body mass index (BMI) z-score and GIR. Leptin accounted for a significant proportion of the variability of testosterone in T1D. However, despite reduced IS, there was no association between IS and testosterone in T1D adolescents. These observations suggest that the mechanisms affecting testosterone may differ between adolescent males with and without T1D.

Response to Comment on: Aeberli et al. Moderate Amounts of Fructose Consumption Impair Insulin Sensitivity in Healthy Young Men: A Randomized Controlled Trial. Diabetes Care 2013;36:150–156

We appreciate the interest in our recent article on the effects of fructose consumption on insulin sensitivity in young men (1), even though we do not agree with White’s (2) view that our data do not support our conclusion. However, considering his affiliations in the sugar-sweetened beverages (SSBs) industry, his critique is neither new nor surprising. Let us first clarify the study design. Subjects received 40 g (medium fructose [MF]) and 80 g (high fructose [HF]) of fructose per day. Assuming an energy intake of a sedentary study population around 2,400–2,500 kcal/day, this represents 6–7% and 13–14% of total energy intake. Dietary intake was assessed to exclude significant …

Diminished Insulin-Mediated Forearm Blood Flow and Muscle Glucose Uptake in Young Men with Low Birth Weight

Background: Low birth weight (LBW) is associated with increased risk of type 2 diabetes and cardiovascular disease. We studied endothelial function and insulin sensitivity in young men with LBW (n = 22) and controls (n = 22). Methods: Insulin sensitivity and endothelial function was studied with venous occlusion plethysmography and intra-arterial infusions of adenosine and acetylcholine, before and during a hyperinsulinemic isoglycemic clamp. Results: Forearm blood flow response to systemic hyperinsulinemia was diminished in LBW compared to controls (p < 0.05). Fractional arteriovenous glucose extraction was similar, and consequently insulin-stimulated forearm glucose clearance was diminished in LBW compared with controls (0.8 ± 0.09 vs. 1.4 ± 0.36 ml·100 ml^–1·min^–1, respectively, p < 0.05). Forearm blood flow response to adenosine and acetylcholine with or without insulin stimulation did not differ between groups. Whole-body glucose uptake was lower in LBW than controls (8.7 ± 0.5 and 9.1 ± 0.6 mg·min^–1·kg^–1 lean body mass); however, this was not significant. Conclusions: Forearm blood flow response to insulin is impaired in LBW, whereas the response to adenosine and acetylcholine is preserved. The impaired insulin-mediated increase in bulk flow in LBW may be due to an impairment of insulin-mediated capillary recruitment independent of – or preceding – whole-body insulin resistance in LBW subjects.

The SstI polymorphism of the apo C-III gene is associated with insulin sensitivity in young men.

Insulin resistance is considered to be a risk factor for diabetes and coronary heart disease and is determined by the interaction between genetic and environmental factors. The SstI polymorphism in the apolipoprotein C-III gene has been related to the presence of different features of the insulin resistance syndrome. We investigate if this mutation influences the peripheral effect of insulin in healthy young subjects (30 men and 29 women) eating a westernised diet. We investigated peripheral insulin sensitivity with the insulin suppression test after a 28-day westernised high-saturated fat diet (38% total fat and 18% saturated fat with 115 mg of cholesterol per 1000 Ju). Steady state plasma glucose values were lower in S1-S1 compared with S1-S2 men (p=0.018 by ANOVA), but not in women (p=0.723). There was no difference between carriers and non-carriers of the S2 allele in relation to incidence and sensitivity; although on subgroup analysis there was an effect in men but not in women.