Preventive Effects of Low Parathyroid Hormone Levels on Hip Fracture in Patients with Vitamin D Deficiency

BACKGROUND: The objective of the current study is to determine the role of serum parathyroid hormone (PTH) on hip fracture development by retrospectively analyzing the relationship between vitamin D and PTH levels and hip fracture prevalence. METHODS: Among 288 patients over 50 years of age, 113 patients with hip fracture and 111 controls without fracture were analyzed after excluding patients with conditions affecting bone metabolism. Bone mineral density and serum biochemical markers were measured, while demographic data were obtained. Patients were divided into 4 groups according to serum 25-hydroxy-vitamin D (25-[OH]D) and PTH levels: LowD+LowP (low 25[OH]D and PTH); LowD+HighP, (low 25[OH]D and high PTH); HighD+LowP (high 25[OH]D and low PTH); and HighD+HighP, patients with (high 25[OH]D and PTH). Measured values and percentages of patients with hip fracture in each group were then determined and compared. RESULTS: The number of patients included in the LowD+LowP, LowD+HighP, HighD+LowP, and HighD+HighP groups was 116, 17, 87, and 4, while the percentages of patients with hip fracture in the same groups were 60.3%, 88.2%, 27.6%, and 100%, respectively. The percentage of hip fracture was significantly lower in the LowD+LowP than the LowD+HighP group (P=0.049). CONCLUSIONS: Patients with low serum 25(OH)D and PTH levels showed lower hip fracture prevalence, indicating the potential protective role of low PTH levels on bone health in patients with vitamin D deficiency. Therefore, clinicians should pay more attention to the possibility of fractures in patients with vitamin D deficiency who present with high PTH levels.