Grashow · JAMA neurology 2019 · cross-sectional study · n=3409

Association of Concussion Symptoms With Testosterone Levels and Erectile Dysfunction in Former Professional US-Style Football Players.

Cited 47 times in the scientific literature.

Level 4 - case-series / case-control

Cross-sectional survey study

PubMed 31449296 · doi:10.1001/jamaneurol.2019.2664 · record verified 2026-08-29

What was done

A cross-sectional survey was administered to former professional US-style football players between January 2015 and March 2017. Of 13,720 eligible players contacted, 3,506 responded (25.6% response rate), and 3,409 (mean age 52.5 years) were analyzed. Concussion symptom scores were calculated by summing the frequency of 10 self-reported symptoms at the time of past football-related head injuries. Outcomes were self-reported indicators of low testosterone levels and erectile dysfunction (ED), defined as receiving clinician recommendations or prescriptions for low testosterone or ED medications. Multivariable models adjusted for demographic characteristics, football exposures, and current health factors.

What was found

Among 3,409 former players, the prevalence of indicators of low testosterone levels and ED was 18.3% and 22.7%, respectively. Adjusted models demonstrated a significant monotonically increasing association between concussion symptom score and both outcomes: - Low testosterone indicator: highest vs lowest quartile OR = 2.39 (95% CI, 1.79-3.19; P < .001) - Erectile dysfunction indicator: highest vs lowest quartile OR = 1.72 (95% CI, 1.30-2.27; P < .001)

Why it matters

This study shows an association between sports-related concussion symptom burden and later self-reported neuroendocrine and sexual dysfunction, supporting further clinical screening in athletes with past head trauma.

Limits

The study used a cross-sectional design that cannot determine causality. Outcomes and head trauma histories relied entirely on retrospective self-report rather than direct serum hormone assays, clinical records, or medical examinations. The 25.6% response rate introduces potential self-selection and recall bias.

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