Factors associated with osteocalcin in men with spinal cord injury: findings from the FRASCI study.

Study Design: Cross-sectional study.

Objective: To assess the association between clinical and demographic factors, bisphosphonate use, and circulating total osteocalcin levels in men with chronic spinal cord injury.

Setting: Veteran Affairs Medical Center.

Methods: As part of an epidemiological study assessing SCI-related health conditions, 214 men with chronic spinal cord injury underwent a DXA scan and provided a blood sample and information regarding SCI, medication use, and fracture history. General linear models were used to assess clinical/demographic factors of osteocalcin, and if significant, were included in multivariate model.

Results: We found that total osteocalcin levels increased 1.0 ng/ml for every kilogram increase in lean mass (p = 0.05) and increased 4.53 ng/ml for every ng/ml increase in C-telopeptide level (p < 0.0001). Osteocalcin levels were greater in people reporting no alcohol consumption compared with drinkers (15.49 ng/ml versus 18.58 ng/ml, p < 0.0002), lower in diabetics compared with nondiabetics (15.23 ng/ml versus 18.92 ng/ml, p = 0.0001), and lower in bisphosphonate users compared with nonusers (15.50 ng/ml versus 18.58 ng/ml, p < 0.03). The association between age and osteocalcin was not significant (p = 0.06). This model explained 58% of the variation in ln osteocalcin levels (model p < 0.0001, r = 0.58).

Conclusions: Total osteocalcin levels vary based on health habits, body composition, comorbid illnesses, and bisphosphonate use in men with chronic spinal cord injury.