Risk factors for the development of osteoporosis after spinal cord injury. A 12-month follow-up study

• Published in: Osteoporosis international Vol. 26; no. 9; pp. 2273 - 2280
• Main Authors: Gifre, L., Vidal, J., Carrasco, J. L., Muxi, A., Portell, E., Monegal, A., Guañabens, N., Peris, P.
• Format: Journal Article
• Language: English
• Published: London Springer London 01-09-2015; Springer Nature B.V
• Subjects: Absorptiometry, Photon - methods; Adult; Biomarkers - blood; Bone density; Bone Density - physiology; Bone Remodeling - physiology; Endocrinology; Female; Femur - physiopathology; Follow-Up Studies; Humans; Lumbar Vertebrae - physiopathology; Male; Medicine; Medicine & Public Health; Middle Aged; Original Article; Orthopedics; Osteoporosis; Osteoporosis - etiology; Osteoporosis - physiopathology; Prospective Studies; Rheumatology; Risk Factors; Spinal cord injuries; Spinal Cord Injuries - complications; Spinal Cord Injuries - physiopathology; Young Adult; BMD; Osteoporosis; Spinal cord injury; Bone turnover markers; Risk factors
• ISSN: 0937-941X; 1433-2965
• DOI: 10.1007/s00198-015-3150-x

Summary
Spinal cord injury (SCI) has been associated with a marked bone loss after injury and a consequent increased risk of osteoporosis. The evaluation of bone mineral density shortly after SCI is a simple and effective method for predicting the development of osteoporosis during the first year after SCI.
Introduction
Spinal cord injury (SCI) has been associated with a marked bone loss after injury and a consequent increased risk of osteoporosis and fractures. The aim of this study was to analyze the factors associated with osteoporosis development short-term after SCI.
Methods
We included patients with complete recent SCI (<6 months) evaluating bone turnover markers (P1NP, bone ALP, and sCTx), 25-OH-vitaminD (25OHD) levels, and lumbar and femoral BMD (Lunar, Prodigy) at baseline, 6 and 12 months after SCI. The risk factors for osteoporosis analyzed included the following: age, gender, BMI, toxic habits, bone turnover markers, 25OHD levels, lumbar and femoral BMD, level, severity and type of SCI, and days-since-injury. Osteoporosis was defined according to WHO criteria.
Results
Thirty-five patients aged 35 ± 16 years were included, and 52 % developed osteoporosis during the 12-month follow-up. These latter patients had lower BMD values at femur and lumbar spine and higher bone turnover markers at baseline. On multivariate analysis, the principal factors related to osteoporosis development were as follows: total femur BMD <1 g/cm
2
(RR, 3.61; 95 % CI 1.30–10.06,
p
 = 0.002) and lumbar BMD <1.2 g/cm
2
at baseline (0.97 probability of osteoporosis with both parameters under these values). Increased risk for osteoporosis was also associated with increased baseline values of bone ALP (>14 ng/mL) (RR 2.40; 95 % CI 1.10–5.23,
p
 = 0.041) and P1NP (>140 ng/mL) (RR 3.08; 95 % CI 1.10–8.57,
p
 = 0.017).
Conclusions
The evaluation of BMD at the lumbar spine and femur short-term after SCI is a simple, effective method for predicting the development of osteoporosis during the first year after SCI. Our results also indicate the need to evaluate and treat these patients shortly after injury.