Vitamin D Deficiency/Insufficiency Is Associated with Risk of Osteoporotic Thoracolumbar Junction Vertebral Fractures

BACKGROUND: The association between serum vitamin D level and vertebral fracture (VFx) remains controversial. The purpose of this study was to determine whether serum 25-hydroxy vitamin D (25(OH)D) level is associated with osteoporotic thoracolumbar junction VFx in elderly patients. MATERIAL/METHODS: From Jan 2013 to Dec 2017, this retrospective case-control study included 534 patients with primary osteoporotic thoracolumbar junction VFx (T10–L2) and 569 elderly orthopedic patients with back pain (without osteoporotic VFx) as controls. Serum 25(OH)D levels were measured and the association with osteoporotic VFx was analyzed. Other clinical data, including BMI, comorbidities, and bone mineral density (BMD), were also collected and compared between these 2 groups. RESULTS: It was shown that 25(OH)D levels were significantly lower in patients with T10–L2 VFx than in control patients. Among 534 VFx patients, 417 (78.1%) patients showed grade 2–3 fracture. Serum 25(OH)D levels were significantly related to affected vertebral numbers and VFx severities. The VFx risk was 28% lower (OR=0.72, 95% CI 0.62–0.83) per increased SD in serum 25(OH)D. Compared with the 1(st) quartile (mean 25(OH)D: 29.67±6.18 nmol/L), the VFx risk was significantly lower in the 3(rd) (mean 25(OH)D: 60.91±5.12nmol/L) and 4(th) quartiles (mean 25(OH)D: 103.3±44.21nmol/L), but not in the 2(nd) quartile (mean 25(OH)D: 45.40±3.95 nmol/L). In contrast, the VFx risk was significantly increased in the 1(st) quartile (OR=1.87, 95% CI 1.42–2.45) compared with the 2(nd)–4(th) quartiles. CONCLUSIONS: Vitamin D deficiency/insufficiency was associated with risk of osteoporotic thoracolumbar junction vertebral fractures in elderly patients.