Pituitary-Testis Relationships in Paraplegic Men

Testosterone levels among men with spinal cord injury: relationship between time since injury and laboratory values

OBJECTIVES

The objectives of the present study were to determine the prevalence of low testosterone among a sample of men with spinal cord injury and to examine the relationship among testosterone, time since injury, and select laboratory values.

DESIGN

Participants were 102 men with spinal cord injury participating in inpatient or outpatient rehabilitation. Data included total serum testosterone level, demographic and injury information, and laboratory values.

RESULTS

Sixty percent of men with spinal cord injury had low testosterone levels. The median testosterone level for the entire sample was 220 ng/dl (normal reference range = 241-827 ng/dl). Low testosterone was significantly associated with less time since injury, lower hemoglobin, and higher prolactin in the univariate analyses at P < 0.05.

CONCLUSIONS

The results indicate that men with spinal cord injury are at risk for low serum testosterone. Testosterone levels were also related to time since injury and hemoglobin and prolactin levels. These findings suggest the need for changes to occur in clinical practice. Guidelines are needed for when and how often testosterone monitoring should be conducted. Future research should address the pathophysiology of low testosterone and the outcomes of testosterone treatment.

Testosterone Levels Among Men with Spinal Cord Injury Admitted to Inpatient Rehabilitation

OBJECTIVE

Although previous research has shown an association between spinal cord injury (SCI) and testosterone production, these studies have yielded inconsistent results. The present study documented the prevalence of low testosterone among men with SCI.

DESIGN

Participants were 92 men with SCI participating in inpatient rehabilitation. Data included total serum testosterone level, demographic and injury information, neurologic level and degree of incomplete function, American Spinal Injury Association Impairment Scale grade, and additional laboratory values, including prealbumin, albumin, hematocrit, and aspartate aminotransferase.

RESULTS

The median testosterone level for men who sustained injuries <4 mos earlier was 160 ng/dl. Testosterone categories were significantly associated with age, time since injury, hematocrit, albumin level, and aspartate aminotransferase in the univariate analyses. Age, time since injury, and hematocrit levels were significant predictors of low testosterone in the multivariate analysis.

CONCLUSION

The prevalence of low testosterone among men with acute SCI seems to be high. The results suggest the need for routine screening for low testosterone among men with SCI and consideration given to testosterone replacement therapy. Future research is needed to investigate the etiology, pathogenesis, and potential avenues for treatment of low testosterone among men with SCI.

Endocrine profiles and semen quality in spinal cord injured men

PURPOSE

To evaluate the hypothalamic-pituitary-testis (HPT) axis, endocrine profiles and semen quality in men with spinal cord injury (SCI).

MATERIALS AND METHODS

Fifty-five men with SCI were studied. Serum levels of FSH, LH, testosterone, oestradiol and prolactin (PRL) were determined; the LH-releasing hormone (LHRH) stimulation test and a semen analysis were performed, and testicular volumes were measured. Thirty-six age-matched healthy male volunteers and 34 noninjured infertile men served as controls.

RESULTS

Eight SCI subjects had low basal LH, four had low basal FSH, and 16 had decreased basal serum levels of LH and FSH. Of subjects with lower serum levels of gonadotrophins (LH and/or FSH), nine had low serum testosterone and seven had hyperprolactinaemia. Serum levels of oestradiol were similar for all groups. There were increased LH and FSH responses to LHRH in SCI subjects compared to normal controls, but this difference was only statistically significant in SCI subjects with lower than normal serum levels of LH and/or FSH. There was no significant difference in testis volume between SCI subjects and controls. The mean semen volume in SCI subjects was lower than from controls, but the difference was not statistically significant. Sperm motility and percent normal sperm morphology were lower in SCI compared to normal controls but not to infertile control subjects. In total, 51% and 86% of SCI subjects had at least one hormonal or axis abnormality, respectively.

CONCLUSION

We conclude that hypogonadotropism in SCI subjects is likely to be secondary to altered neural or hormonal pathways between the hypothalamus and the pituitary gland, and that these endocrine abnormalities may be the mechanisms contributing to impairment of semen quality.

Level of injury and hormone profiles in spinal cord-injured men

OBJECTIVES

To evaluate the level of injury and endocrine profiles in men with spinal cord injury (SCI).

METHODS

Seventy-six men with SCI at different levels were studied, using uninjured normal and infertile subjects as controls.

RESULTS

Compared with normal controls, the subjects with SCI (50%) had lower serum levels of luteinizing hormone, follicle-stimulating hormone, and testosterone. Subjects with T8-T11 and T12-L5 injury had the highest and lowest incidence of hormonal abnormalities, respectively. All subjects with hyperprolactinemia (n = 5) had T8-T11 injuries.

CONCLUSIONS

The results of our study indicate that subjects with SCI have an altered central neurotransmitter tone, and the likelihood of these abnormalities (hypogonadotropism) are higher in men with low thoracic SCI.

Sexual function in spinal cord lesioned men

STUDY DESIGN

Review of literature.

OBJECTIVE

To review the physical aspects related to penile erection, ejaculatory dysfunction, semen characteristics, and techniques for enhancement of fertility in spinal cord lesioned (SCL) men.

SETTING

Worldwide: individuals with traumatic as well as non-traumatic SCL.

RESULTS

Recommendations for management of erectile dysfunction in SCL men: If it is possible to obtain a satisfactory erection but of insufficient duration, then try to use a venous constrictor band to find out if this is sufficient to maintain the erection. Otherwise we recommend Sildenafil. If Sildenafil is not satisfactory then use intracavernous injection with prostaglandin E(1) (some SCL men may prefer cutaneous or intraurethral application). We discourage the implantation of penile prosthesis for the sole purpose of erection. Recommendations for management of ejaculatory dysfunction in SCL men: Penile vibratory stimulation (PVS) to induce ejaculation is recommended as first treatment choice. If PVS fails, SCL men should be referred for electroejaculation (EEJ). Semen characteristics: Impaired semen profiles with low motility rates are seen in the majority of SCL men. Recently reported data gives evidence of a decline in spermatogenesis and motility of ejaculated spermatozoa shortly after (few weeks) an acute SCL. It is suggested that some factors in the seminal plasma and/or disordered storage of spermatozoa in the seminal vesicles are mainly responsible for the impaired semen profiles in men with chronic SCL. Fertility: Home insemination with semen obtained by PVS and introduced intravaginally in order to achieve successful pregnancies may be an option for some SCL men and their partners. The majority of SCL men will further enhance their fertility potential when using either PVS or EEJ combined with assisted reproduction techniques such as intrauterine insemination or in vitro fertilization with or without intracytoplasmic sperm injection.

The hypothalamus-pituitary-ovary and hypothalamus-pituitary-thyroid axes in spinal cord-injured women

Sixteen women with spinal cord injury (SCI) underwent studies of the hypothalamus-pituitary-ovary (HPO) and hypothalamus-pituitary-thyroid (HPT) axes with luteinizing hormone (LH) releasing hormone (LHRH) and thyrotropin (TSH) releasing hormone (TRH) stimulation tests during the early follicular phase. The mean interval from injury to participation in this study was 7.5 years (range, 1.5 to 13.1). All subjects were menstruating regularly. Five (35.7%) SCI subjects who were menstruating before injury had postinjury amenorrhea for 1 to 12 months, and the other nine (64.3%) SCI subjects had no interruption of menstruation after injury. Two SCI subjects whose injury occurred in preadolescence proceeded to menarche without any delay. The amount of menstrual flow was noted to be reduced in nine (64.3%) SCI subjects. Two and three SCI subjects had elevated follicle-stimulating hormone (FSH) and prolactin (PRL) levels, respectively. LH responses to LHRH were significantly higher in the SCI group (P < .001). Ten (62.6%) SCI subjects had enhanced LH responses to LHRH. The mean TSH, PRL, and FSH responses to TRH and LHRH of the SCI group were not significantly different from those of age-matched controls. However, five (31.2%), four (25.0%), and five (31.2%) SCI subjects had enhanced TSH, PRL, and FSH responses to TRH and LHRH, respectively. Six (37.5%) SCI subjects had a delayed FSH response to LHRH. In total, 13 (81.2%) SCI subjects had at least one axis abnormality. These findings are consistent with the hypothesis that changes of central neurotransmitters may occur after SCI.

Suppression of the hypothalamus-pituitary somatotrope axis in men with spinal cord injuries

Thirty-two men with spinal cord injury (SCI) were studied for evaluation of the hypothalamus-pituitary somatotrope axis, using growth hormone-(GH)-releasing hormone (GHRH) and insulin-induced hypoglycemia. Twenty-six age-matched normal male volunteers served as controls. Six SCI subjects (18.7%) had elevated basal follicle-stimulating hormone (FSH) levels, eight (25.0%) had hyperprolactinemia, and 11 (34.4%) had reduced serum insulin-like growth factor-1 (IGF-1) levels. Twenty SCI subjects (62.5%) had reduced and/or delayed GH responses to GHRH, and eight (25.8%) had reduced GH response to insulin-induced hypoglycemia. Seven of eight hyperprolactinemic SCI subjects showed reduced GH response to GHRH and/or insulin-induced hypoglycemia. These findings are consistent with the notion that SCI subjects have a reduced central dopaminergic tone.

Endocrine profiles and semen quality of spinal cord injured men

We characterized endocrine profiles and semen quality in spinal cord injury subjects using noninjured normal and infertile subjects as controls. Compared to normal controls, spinal cord injury subjects had lower serum levels of luteinizing hormone and follicle-stimulating hormone. Subjects with spinal cord injuries between the T8 and T10 levels had a higher incidence of hormone outliers compared to subjects with injuries at other levels. Sperm motility and per cent normal sperm morphology were lower in spinal cord injury subjects compared to normal controls but not to infertile control subjects. Spinal cord injury subjects with elevated follicle-stimulating hormone levels were azoospermic. We conclude that endocrine abnormalities are likely to accompany spinal cord injury but may not be the sole mechanism contributing to impairments in semen quality.

Pituitary-testicular and pituitary-thyroid axes in spinal cord-injured males

Thirty spinal cord-injured (SCI) males were studied for evaluation of their pituitary-testicular and pituitary-thyroid axes using combined luteinizing hormone-releasing hormone (LHRH) and thyrotropin-releasing hormone (TRH) tests and electroejaculated semen analyses. Thirty age-matched normal male volunteers served as controls. There were four subjects with low serum triiodothyronine (T3) levels, one with elevated serum follicle-stimulating hormone (FSH) level, eight with elevated serum testosterone levels, and 11 with elevated serum prolactin levels. There were significantly elevated luteinizing hormone (LH) responses to LHRH in SCI subjects when compared with normal controls. There were 16 (53.3%) SCI subjects who had exaggerated and/or prolonged LH responses. Among them, six subjects also had elevated FSH responses. There were eight and four subjects whose thyrotropin (TSH) and prolactin responses to TRH were exaggerated, respectively. Marked impaired motility was observed in 56 electroejaculated semen samples from 16 SCI subjects. There was a significant correlation between LH and total sperm count. Our data suggest that there is a reduced central dopaminergic tone in SCI subjects.

Assisted fertility in complete paraplegia: case report

A 34-year-old paraplegic man with a spinal cord injury complete below the 6th thoracic segment fathered a child by artificial insemination using semen obtained by electro-ejaculation. A long fertility programme culminated in the delivery of a healthy male child weighing 3665 g in April 1987. Guidelines for a comprehensive fertility programme are discussed briefly.

Infertility in spinal-cord injured male

Sterility in spinal-cord injured (SCI) men is believed to be caused by ejaculatory dysfunction, genital ductal blockage secondary to infection, and/or impaired spermatogenesis. Semen from SCI men demonstrates diminished numbers of motile, morphologically normal sperm. Testicular biopsies demonstrate impaired spermatogenesis. Leydig and Sertoli cells appear to be normal. Endocrine evaluations reveal normal testosterone levels with an adequate Leydig cell reserve. Luteinizing hormone (LD) and follicle-stimulating hormone (FSH) levels are normal or high with normal or exaggerated stimulation responses. Acute depressions in testosterone, FSH, and LH levels can be seen following SCI, most markedly in quadriplegics. A normal hypothalamic-pituitary-testicular axis is implied by these findings, indicating a primary hypogonadism. Causes of impaired spermatogenesis may include local testicular temperature elevations, nondrainage of the reproductive tract, antisperm antibodies, and recurrent genitourinary infections. Treatment of infertility involves removal of these offending factors, and research is needed to correlate the impaired spermatogenesis with these factors.