Prevalence of Low Testosterone and Predisposing Risk Factors in Men With Type 1 Diabetes Mellitus: Findings From the DCCT/EDIC

Context: Previous studies have demonstrated lower testosterone concentrations in men with type 2 diabetes mellitus. Data in men with type 1 diabetes mellitus (T1DM) are limited. Objective: Our objective was to determine the prevalence of low testosterone in men with T1DM and identify predisposing factors. Design, Setting, and Participants: This was a cross-sectional study of men with T1DM participating in UroEDIC (n = 641), an ancillary study of urologic complications in the Epidemiology of Diabetes Interventions and Complications (EDIC). Main Outcome Measures: Total serum testosterone levels were measured using mass spectrometry, and SHBG levels were measured using sandwich immunoassay on samples from EDIC year 17/18. Calculated free testosterone was determined using an algorithm incorporating binding constants for albumin and SHBG. Low testosterone was defined as total testosterone <300 mg/dL. Multivariate regression models were used to compare age, body mass index, factors related to diabetes treatment and control, and diabetic complications with testosterone levels. Results: Mean age was 51 years. Sixty-one men (9.5%) had testosterone <300 mg/dL. Decreased testosterone was significantly associated with obesity (P < .01), older age (P < .01) and decreased SHBG (P < .001). Insulin dose was inversely associated with calculated free testosterone (P = .02). Hypertension retained a significant adjusted association with lower testosterone (P = .05). There was no observed significant relationship between lower testosterone and nephropathy, peripheral neuropathy, and autonomic neuropathy measures. Conclusion: The men with T1DM in the EDIC cohort do not appear to have a high prevalence of androgen deficiency. Risk factors associated with low testosterone levels in this population are similar to the general population.