IntroductionThe prevalence of hypogonadotropic hypogonadism (HH) in patients with type 2 diabetes mellitus is higher than in the general population and leads to detrimental effects on metabolic control, lipid profile, and body composition. Few studies have examined its role in type 1 diabetes mellitus. AimTo determine the prevalence of HH in patients with type 1 diabetes and associated risk factors. Main Outcome MeasuresClinical and biochemical parameters were gathered on initial evaluation. An HH score creating different experimental models was devised to calculate the risk of HH for an individual with type 1 diabetes. MethodsCross-sectional study of 181 male patients with type 1 diabetes consecutively admitted to the Diabetes outpatient clinics of three urban hospitals. All participants were Caucasians aged18 years with type 1 diabetes duration of more than 6 months. ResultsOne hundred and eighty-one male patients with a mean age of 44.213.2 years and a type 1 diabetes duration of 18.9 +/- 12.7 years were included. Fifteen patients had HH, representing a prevalence of 8.3% (95% confidence interval [CI]: 4.3-12.3%). Age (odds ratio [OR] 1.066 [95% CI: 1.002-1.134]), waist circumference (OR 1.112 [95% CI: 1028-1203]), and insulin requirements ([IU/Kg] x10 [OR 1.486 {95% CI: 1052-2.098}]) were independently associated with the presence of HH. The model that best predicted HH generated this formula: HH-score=(1.060xage)+(1.084xwaist circumference)+(14.00xinsulin requirements)+triglycerides, where age was expressed in years, waist circumference in cm, insulin requirements in IU/kg/d, and triglycerides in mg/dL. An HH score>242.4 showed 100% sensitivity and 53.2% specificity for HH diagnosis; positive and negative predictive values were 17.0 % and 100%, respectively. ConclusionsOne in 10 men with type 1 diabetes presents HH. This condition is associated with age, waist circumference, and insulin requirements. A simple formula based on clinical parameters can rule out its presence. Chillaron JJ, Fernandez-Miro M, Albareda M, Vila L, Colom C, Fontsere S, Pedro-Botet J, Flores-Le Roux JA, and TEST-DM1 Study Group. Age, insulin requirements, waist circumference, and triglycerides predict hypogonadotropic hypogonadism in patients with type 1 diabetes. J Sex Med 2015;12:76-82.