TSH oscillations in young patients with type 1 diabetes may be due to glycemic variability.

PURPOSE: A relationship between thyroid dysfunction and diabetes mellitus has been described by several authors but the role of glycemic variability is still unclear. We planned the present study to evaluate the influence of glycemic variability on thyroid hormones and TSH concentrations in patients with type 1 diabetes mellitus (T1DM). METHODS: Seventy-seven young patients with T1DM were enrolled and evaluated for basal glucose concentrations, HbA1c, thyroid hormones and TSH concentrations. Glucose variability was investigated by considering the standard deviation of blood glucose readings and by calculating the mean amplitude of glycemic excursions and continuous overlapping net glycemic action (CONGA). The low (LBGI) and high (HBGI) blood glucose indices were also calculated. The correlations between TSH, thyroid hormones, glycemia and HbA1c were studied in patients and in controls, whereas those between TSH, thyroid hormones and indices of glucose variability only in patients. RESULTS: No correlations were observed in T1DM patients between free thyroid hormones and glycemic values, HbA1c and indices of glucose variability, while an inverse correlation was observed between TSH levels and glycemic values (r = -0.27; p = 0.01), CONGA index (r = -0.35; p = 0.001) and HBGI (r = -0.28; p = 0.01) but not with HbA1c (r = -0.1; p = 0.47). CONCLUSIONS: Our results suggest a direct action of glycemic excursions on TSH secretion, regardless of variations of thyroid hormone concentrations. Thus, the evaluation of thyroid function through the assay of TSH concentrations in these patients should be made, if possible, by multiple samples on patients in euglycemic state to avoid underestimation or overestimation of thyroid dysfunction due to a wrong diagnosis of euthyroidism or dysthyroidism with consequent inappropriate choice of therapeutic options.

Erectile dysfunction in young men with type 1 diabetes.

Erectile dysfunction (ED) is a common comorbidity of diabetes mellitus, but few studies investigated its prevalence in type 1 diabetes. The objective of this study was to evaluate the prevalence and correlates of ED in young men with type 1 diabetes treated with different intensive insulin regimens. The study population included 151 type 1 diabetic men, aged 18-35 years, and 60 healthy age-matched controls. Ninety-four men were treated with multiple daily injections of insulin (MDI), and the remaining 71 with continuous subcutaneous insulin infusion (CSII). All participants in the study completed the International Index of Erectile function (IIEF-5), and other validated multiple-choice questionnaires assessing quality of life, physical activity, depressive symptoms and diabetes-related problems. The overall prevalence of ED was higher in diabetic men (37%), as compared with controls (6%, P<0.001). ED prevalence rates were similar in both MDI (36%) and CSII (39%) groups (P=0.326); both were higher compared with controls (P<0.001 for both). More than half of diabetic men (58%) had mild ED. Compared with men without ED, diabetic men with ED showed lower weight, body mass index, fasting glucose, insulin dose and high-density lipoprotein cholesterol levels, and higher self-rating depression score (SRDS). In the multiple regression analysis only the SRDS (P=0.032) were independent predictors of IIEF-5 score in the overall diabetic men. Young men with type 1 diabetes treated with MDI or CSII show a higher prevalence of ED, as compared with healthy age-matched men. Depression was associated with ED in diabetic population.