Abstract :
Objectives: to investigate the association between sex and parathyroid hormone response to severe
vitamin D deficiency after hip fracture. Design: cross-sectional study. Setting: rehabilitation hospital in italy.
Participants: 571 consecutive inpatients with hip fracture and severe vitamin D deficiency (serum 25-
hydroxyvitamin D < 12ng/ml), without hypercalcemia or estimated glomerular filtration rate (gFr) < 15ml/min.
Measurements: in each patient we assessed ptH (by two-site chemiluminescent enzyme-labelled immunometric
assay), 25-hydroxyvitamin D (by immunoenzymatic assay), albumin-adjusted total calcium, phosphate,
magnesium, and creatinine 21.3 ± 6.1 (mean ± sD) days after fracture occurrence. Functional level was assessed
using the Barthel index. ptH response to vitamin D deficiency was classified as either secondary
hyperparathyroidism (serum ptH >75pg/ml) or functional hypoparathyroidism, i.e., inappropriate normal levels
of ptH (≤75pg/ml). Results: among the 571 patients, 336 (59%) had functional hypoparathyroidism, whereas
235 (41%) had secondary hyperparathyroidism. ptH status was significantly different between sexes (p=0.003):
we found functional hypoparathyroidism in 61% of women and 43% of men (secondary hyperparathyroidism in
39% of women and 57% of men). the significance of the between-sex difference was maintained after
adjustment for age, estimated gFr, phosphate, albumin-adjusted total calcium, albumin, Barthel index scores,
25-hydroxyvitamin D, and hip fracture type (either cervical or trochanteric). the adjusted odds ratio was 1.85
(95%ci from 1.09 to 3.13; p=0.023). Conclusions: Data shows that ptH response to vitamin D deficiency was
sex-associated following a fracture of the hip. the higher prevalence of secondary hyperparathyroidism may play
a role in the known prognostic disadvantage found in hip-fracture men.
Keywords :
Hip Fracture , parathyroid hormone , Vitamin D. , Secondary hyperparathyroidism
