Relation of Severity of injury with Testosterone profile & osteoporosis in spinal cord injured men

Principal Investigator: Cristina Sadowsky

Hypothesis: Higher spinal cord injury neurologic level correlates with decreased testosterone level and increased prevalence of secondary osteoporosis. 

Spinal cord injury is more common in young adult men. Because of better care, the life expectancy has increased making them more vulnerable to decreased bone mass. Androgen receptor gene expression is confirmed on osteoblast by RNA blot analysis (Colvard et al, Proc. Natl Acad Sci 86). Osteoporosis is one of the major causes for fractures in spinal cord injury population. Since Mechanisms of osteoporosis after spinal cord injury is not completely clear (Maimoun et al, spinal cord 44), different theories have been proposed. One of them is a hormonal theory (Sheng-Dan Jiang et al, Clinical Endocrinology 65). It is suggested that spinal cord injury causes suppression of hypothalamus-pituitary-gonad axis (Wang et al, AJPMR 71, Tsitouras et al, Hormone and metabolic research 27) which can affect the level of testosterone. Still the studies investigating the effects of spinal cord injury on the testosterone profile have shown conflicting results (Wheeler et al, Spinal Cord 34)(Brackett et al, J Urology 151)(Safarinejad, Urology 58)(Naftchi et al, Arch Phys Med Rehabil 61).

Our center, the International Center for Spinal Cord Injury, has been seeing a large number of adult male with spinal cord dysfunction over the past four years since opening. We intend to collect information including laboratory data of free and total testosterone level and radiological data for osteopenia/osteoporosis obtained by DEXA scan. We will also record age, ethnicity, the underlying disease process, as well as the severity of spinal cord injury based on American Spinal Injury Association (ASIA) classification. We plan to include adult male patient between the ages of 18-70 years that have been seen at our center since June 2004.