Prevalence of undiagnosed testosterone deficiency in aging athletes: does exercise training influence the symptoms of male hypogonadism?

INTRODUCTION

Worldwide many aging males practice sports. A high prevalence of late-onset male hypogonadism has been observed in general population. Sport-participation influences the neuroendocrine system and may decrease serum testosterone.

AIM

This preliminary study was designed to estimate the prevalence and the symptoms of undiagnosed testosterone deficiency in aging athletes.

METHODS

This observational survey was performed in 183 caucasian male athletes >50 years, in the setting of pre-participation screening. Pituitary-gonadal hormones and symptoms of hypogonadism were investigated. Serum total testosterone (TT), sex hormone binding globulin, luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL), free-T4, and thyroid stimulation hormone (TSH) were assayed, and free T, bioactive T, and the LH/TT ratio were calculated. The International Index of Erectile Dysfunction (IIEF-15) and the Center for Epidemiological Studies Depression Scale (CES-D) were administered. Hypogonadal athletes were compared with eugonadal athletes as controls.

MAIN OUTCOME MEASURES

Prevalence and clinical symptoms of severe (TT < 8 nmol/L) or mild (8 nmol/L <or= TT < 12 nmol/L) testosterone deficiency were investigated.

RESULTS

The mean sample age was 61.9 +/- 7.5 years (range 50-75). Severe or mild testosterone deficiency was observed in 12% and 18%, respectively, of overall athletes, with the highest prevalence in athletes >70 years (27.5% and 25.0%, respectively). TT did not correlate with age, training duration, or questionnaire scores. No differences were observed for nonspecific symptoms of hypogonadism, IIEF-15 and CES-D scores between eugonadal and severe hypogonadal athletes.

CONCLUSIONS

Independently of its etiology, a significant percentage of aging athletes had undiagnosed testosterone deficiency. In a relevant number of these cases, testosterone deficiency was not overtly symptomatic. Our results suggest that sport-participation per se can influence the symptoms of hypogonadism. The history of clinical symptoms may be inaccurate to diagnose testosterone deficiency in aging athletes. Future research should address the clinical relevance and the specific risks of testosterone deficiency in aging athletes, and the need of a systematic pre-participation serum testosterone evaluation.