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.