Evaluation of Serum 25-Hydroxyvitamin D3 and Bone Mineral Density in 268 Patients with Hip Fractures

Objective The aim of the present study was to evaluate the relationship among vitamin D nutritional status, bone mineral density, and other factors in elderly patients with brittle hip fractures. Methods The present study was a retrospective analysis of 268 patients, 102 men (38.06%) and 166 women (61.94%), with brittle hip fractures admitted to the Hip Joint Center of Tianjin Hospital from February 2016 to June 2018. The median age of the patients was 74 years (range, 50-93 years). The patients were divided into three groups based on age: <= 69 years, 70-79 years, and >= 80 years. Serum 25-hydroxyvitamin D-3 (25(OH) D-3), parathyroid hormone (PTH), body mass index (BMI), and bone mineral density (BMD) of the lumbar spine, femoral neck, and hip were measured and statistically analyzed. Results The median serum 25(OH)D-3 level of patients was 9.90 (range, 2.60-42.70) ng/mL; the proportion of deficiency was 89.18% and the deficiency was severe in 136 cases (49.25%). The proportion of vitamin D deficiency was significantly lower in men than in women (P = 0.013). With the increase of age, 25(OH)D-3 levels gradually decreased (P = 0.044) and PTH levels gradually increased (P < 0.001). There was significantly negative correlation (P < 0.001) between the levels of serum 25(OH)D-3 and PTH. There were 200 cases (74.63%) in which T-values of BMD were less than -2.5 in any part of the lumbar vertebrae, femoral neck, and hip. T-values in 74 cases (27.61%) were less than -2.5 in all three parts. The T-values of BMD in men were significantly higher than those in men (P < 0.001). With the increase of age, the femoral neck BMD in men gradually decreased (P = 0.016), and the femoral neck and hip BMD in female gradually decreased (P-value was 0.001 and 0.003, respectively). Multivariate analysis suggested that gender and BMI were independent risk factors for BMD, and vitamin D deficiency affected BMD. Conclusion Vitamin D deficiency is common in patients with brittle hip fractures, especially in women. With the increase of age, vitamin D continues to decrease and PTH increases. The decrease of BMD in patients with hip fractures is the result of a combination of age, gender, BMI, and vitamin D content.