Characterization of prostate size, PSA and endocrine profiles in patients with spinal cord injuries

Aims of this study: From cross-sectional and longitudinal population based studies as well as from autopsy studies it is well documented that total prostate volume increases with advancing age. However, it is not well known (1) which factors are ultimately responsible for this growth phenomenon; or (2) at what time in a persons life the growth tends to occur. At present at least a permissive role for testicular androgens is assumed to be involved in growth regulation. Other factors such as growth factors, epithelial-mesenchymal interaction, and the role of intact neural pathways are still poorly understood. We aimed to study a group of men with spinal cord injuries to determine whether the pattern of prostate enlargement would be different in men with partially or completely interrupted innervation of the pelvis and the prostate gland. Materials and methods: Forty-three men from the Spinal Cord Injury (SCI) Service at the VA North Texas Health Care System ranging in age from 27-73 y (mean 51 y) were recruited to participate in this study. Time since SCI ranged from 2-47 (mean 19 y). All patients underwent standardized questionnaire, physical examination, transrectal ultrasonography (TRUS) measurements of total and transition zone volume of the prostate, serum PSA, testosterone (T), dihydrotestosterone (DHT), FSH and LH measurements, some had TRUS guided biopsies taken. Results: By all the measured criteria there were no abnormalities regarding the pituitary-gonadal axis observed in these men. Testicular volume, serum T, DHT and LH were within normal ranges, and when the patients were stratified by age, no differences were identified. There was an age related increase in FSH which has been described in neurologically intact men. Serum PSA increased slightly with advancing age. While total (TPV) and transition zone (TZV) prostate volume increased with age, the groupwise differences by decades of life were not significant. Moreover, when compared to a group of community dwelling men without known prostatic diseases and a clinic cohort of men with BPH, TPV was substantially lower for each decade of life except for men in their 40s, while TZV was substantially lower for men in their 60s. Conclusions: We observed normal age related changes regarding serum PSA and serum FSH without significant changes in other hormonal parameters. All parameters behaved consistent with changes described in neurologically intact populations. However, we did not observe the typical increase in TPV and TZV of the prostate as seen in population, autopsy and clinic patient studies. This interesting finding indicates that factors other than an intact pituitary-gonadal axis and male steroid hormones may be responsible for the normal age related growth of the prostate. Further studies in larger cohorts are needed to corroborate our findings.