Hormone changes in men with spinal cord injuries

The steady state profiles of 63 men with traumatic spinal cord injuries (24 quadriplegics and 39 paraplegics; average age of 31.2 +/- 6.8 yr; 18-44 yr) were studied. The average length of post-traumatic period was 6.2 +/- 5.0 yr, ranging from 8 months to 20 yr. It was found that all the subjects had normal serum thyroxine, thyrotropin, cortisol, growth hormone and plasma adrenocorticotropic hormone. Seven cases (11.1%) had low serum triiodothyronine and eight cases (12.7%) had low serum testosterone. On the other hand, 17 cases (27.0%) had hyperprolactinemia; 9 cases (14.3%) had elevated serum testosterone level; 6 cases (9.5%) had elevated serum follicle-stimulating hormone; and 4 cases (6.3%) had elevated serum luteinizing hormone. The level of spinal cord injury, injury period and patient age had no correlation with other serum hormone changes except that quadriplegic subjects had lower serum triiodothyronine than the paraplegic, with a mean of 1.42 +/- 0.30 v 1.70 +/- 0.36 nmol/liter (P < 0.005). Of the eight subjects who had low serum testosterone, none had elevated gonadotropin. There were also eight subjects with elevated follicle-stimulating hormone and/or luteinizing hormone, six of them had normal serum testosterone and two had elevated serum testosterone. This suggested their hypogonadism did not result primarily from classic primary gonadal failure. It could be speculated that other testicular paracrine factors and/or alteration of hypothalamus-pituitary-testicular axis are involved in the pathogenesis of hypogonadism. Further studies in this field will provide information regarding male reproductive physiology and may have impact on fertility enhancement options for men with spinal cord injuries.