Progressive impairment of testicular endocrine function in ageing men: testosterone and dihydrotestosterone decrease, and luteinising hormone increases, in men transitioning from the 8th to 9th decades of life

Summary

Context

Sex hormone trajectories in ageing men and their health implications remain unclear. We examined longitudinal trajectories and associations of testosterone (T), dihydrotestosterone (DHT), estradiol (E2), luteinising hormone (LH) and sex hormone-binding globulin (SHBG) in oldest old men.

Design

Prospective cohort study.

Participants

We studied 1,025 community-dwelling men median age 75.1 years at baseline with 8.6 years follow-up.

Measurements

Baseline and follow-up T, DHT and E2 were assayed using mass spectrometry. Physical performance was assessed at follow-up. Correlations and covariate-adjusted P-values were determined.

Results

Longitudinal change in T was -2.0%/year, DHT -7.2%/year, LH +7.5%/year, SHBG +5.6%/year while E2 remained stable. Annualised increases in LH correlated with decreases in T and DHT (r=-0.20, P<0.0001 and r=-0.12, P=0.0035 respectively). Higher baseline T correlated with better physical performance at follow-up (e.g. Step test r=0.07, P=0.03), as did higher baseline DHT (e.g. Time to Sit-Stand [TSS] r=-0.07, P=0.01). Larger annualised increases in LH predicted poorer physical performance at follow-up (e.g. TSS r=0.14, P=0.001). Higher T at follow-up was associated with better physical performance (e.g. TSS r=-0.07, P=0.04), as were higher DHT and lower LH. At baseline 24 men (2.4%) had abnormally high LH (>16 IU/L); at follow-up 175 (17.4%) had high LH of whom 70 had low T (<6.4 nmol/L).

Conclusions

Annualised increases in LH are associated with declines in T and DHT, and predict poorer subsequent physical performance in oldest old men. Men transitioning from 8^th to 9^th decades exhibit biochemical evidence of progressively impaired testicular endocrine function, warranting further evaluation.

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