Little is known about the association between vitamin D deficiency and the skeletal phenotypes in primary hyperparathyroidism (PHPT) patients. A low 25-hydroxyvitamin D level was associated with a low bone mineral density and deteriorated hip geometry in women with PHPT in an Asian population where vitamin D deficiency is prevalent.
Introduction: Few studies have examined the effect of vitamin D deficiency on the bone health of primary hyperparathyroidism (PHPT) patients.
Methods: We investigated the skeletal effects of vitamin D deficiency in 79 PHPT patients by assessing bone mineral density (BMD), the trabecular bone score (TBS), and hip geometry, which were measured using dual-energy X-ray absorptiometry (27 men with median age 60 years [53;69]; 52 postmenopausal women with median age of 57 years [53;67]). Cross-sectional data were collected from subjects enrolled in an ongoing PHPT cohort study at Seoul National University Hospital from March 2008 to December 2015.
Results: We classified PHPT patients according to 25-hydroxyvitamin D (25(OH)D) levels (<20 vs. ≥20 ng/ml). After adjusting for age and body mass index, women with vitamin D deficiency had lower BMDs at the lumbar spine (LS) and femur neck (FN) than women who had sufficient levels of vitamin D (LS, 0.903 ± 0.138 vs. 0.998 ± 0.184 g/cm2; FN, 0.715 ± 0.084 vs. 0.791 ± 0.113 g/cm2; P < 0.05). However, the total hip BMD and the TBS were not significantly different between the two groups. In the hip geometry analysis, the cross-sectional area, cross-sectional moment of inertia, and section modulus were also significantly lower in women with vitamin D deficiency than in those without. No significant difference was found in the BMD, TBS, or hip geometry according to 25(OH)D levels in men.
Conclusion: Vitamin D deficiency may be associated with a low BMD and deteriorated hip geometry in postmenopausal women with PHPT.
Keywords: Primary hyperparathyroidism; Skeletal effects; Vitamin D deficiency.