Association of total serum testosterone levels with musculoskeletal parameters in male spinal surgery patients.

Abstract

Age-related decline in male testosterone is associated with reduced bone and muscle mass, increased fat mass, and impaired quality of life. This study investigated the relationships between serum total testosterone (T) levels and bone mineral density, body composition, spinal muscle morphology, and low back pain-related disability in patients undergoing spine surgery. Male patients who underwent spine surgery at our institution and had preoperative serum total testosterone (total T) levels measured were included in this study. Pearson's correlation coefficients were used to assess associations between total T and bone metabolism markers, body composition, physical function, spinal muscle cross-sectional areas (CSAs) on MRI, and clinical outcomes including the Roland-Morris Disability Questionnaire (RDQ) and Aging Males' Symptoms (AMS) scale. Multiple linear regression analysis was performed to identify independent associations. Thirty-eight patients (mean age 73.7 years) were included. Total T levels correlated negatively with age (r = -0.35, P < 0.05). Positive correlations with total T levels were observed for CSAs of the psoas major (r = 0.49, P < 0.05) and paraspinal muscles (r = 0.58, P < 0.05). RDQ scores were negatively correlated with total T levels both preoperatively (r = -0.48, P < 0.05) and postoperatively (r = -0.64, P < 0.05). The improvement rate for RDQ was positively correlated (r = 0.35, P < 0.05) and AMS scores were negatively correlated with total T levels (r = -0.35, P < 0.05). In contrast, no significant associations were observed with body fat percentage, bone mineral density, bone turnover markers, grip strength, or skeletal muscle mass. In multivariate analysis, total T was independently associated with paraspinal muscle CSA but not psoas CSA, after adjustment for age. Lower serum total T levels are independently associated with paraspinal muscle atrophy and greater low back pain-related disability in elderly men undergoing spine surgery. Serum total T may serve as a clinically useful biomarker of musculoskeletal status and predictor of postoperative functional outcomes.