Acute serum androgen levels and post-rehabilitation functioning in spinal cord injury: findings from SwiSCI.

Abstract

Background: Spinal cord injury (SCI) is associated with long-term limitations in daily functioning and secondary complications, including hormonal dysregulation.

Aim: The aim of this paper was to investigate the association between serum androgen levels within 30 days post-SCI and functioning during initial inpatient rehabilitation.

Design: Prospective cohort study.

Setting: Four specialized SCI rehabilitation centers in Switzerland.

Population: Individuals with newly diagnosed traumatic or non-traumatic SCI, undergoing specialized initial inpatient rehabilitation in Switzerland.

Methods: Nested in the prospective Swiss Spinal Cord Injury Cohort Study (SwiSCI), functioning metrics and serum androgen levels (total testosterone [TT], free testosterone [FT], sex hormone-binding globulin, dehydroepiandrosterone [DHEA], and DHEA sulfate [DHEAS]) were measured at baseline and followed-up until discharge from initial inpatient rehabilitation. Functioning was operationalized with the interval-based Spinal Cord Independence Measure version III (SCIM-III). Multivariable time-varying regression analyses were performed, adjusting for confounders. Missing data were handled by multiple imputations.

Results: Participants (N.=80; 15 (19%) female) had a median follow-up of 167 days (IQR:128-224). In males, lower baseline FT was associated with a significantly lower rate of functioning improvement in all models, from baseline to three months after the SCI (e.g., univariable model=-35.9 [95% CI:-79 to -3], P value=0.03) and also from baseline to discharge from inpatient rehabilitation (e.g., in males and age-adjusted model=-49.2 [95% CI:-118 to -2 ], P value=0.04). Similarly, baseline FT levels were positively associated with functioning at discharge (e.g., in the fully-adjusted model, one SD increase in FT was associated with a 26.9% increase in functioning [95% CI: 9 to 42, P=0.01]). Similar trends were observed for TT. DHEA and DHEAS were negatively associated with the improvement in functioning and results were significant only in subgroup analyses. All results for females were null.

Conclusions: Our results suggest that low testosterone levels in the acute phase of SCI reduce the rate of functioning improvement and total functioning gained during initial inpatient rehabilitation in males.

Clinical rehabilitation impact: Our results underscore the potential role of early androgen assessment and modulation in optimizing rehabilitation outcomes in males with SCI.