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.