Mineral metabolism disorders, vertebral fractures and aortic calcifications in stable kidney transplant recipients: The role of gender (EMITRAL study)

Abstract

Background and objectives: The relationship between mineral metabolism disorders, bone fractures and vascular calcifications in kidney transplant recipients has not been established. Method: We performed a cross-sectional study in 727 stable recipients from 28 Spanish transplant clinics. Mineral metabolism parameters, the semi-quantification of vertebral fractures and abdominal aortic calcifications were determined centrally. Results: Vitamin D deficiency (25OHD3 <15 ng/ml) was more common in female recipients at CKD-T stages I–III (29.6% vs 44.4%; p = 0.003). The inverse and significant correlation between 25OHD3 and PTH was gender-specific and women exhibited a steeper slope than men (p = 0.01). Vertebral fractures (VFx) with deformity grade ≥2 were observed in 15% of recipients. Factors related to VFx differed by gender; in males, age (OR 1.04; 95% CI 1.01–1.06) and CsA treatment (OR: 3.2; 95% CI: 1.6–6.3); in females, age (OR 1.07; 95% CI: 1.03–1.12) and PTH levels (OR per 100 pg/ml increase: 1.27; 95% CI: 1.043–1.542). Abdominal aortic calcifications were common (67.2%) and related to classical risk factors but not to mineral metabolism parameters. Conclusions: Vitamin D deficiency is more common among female kidney transplant recipients at earlier CKD-T stages, and it contributes to secondary hyperparathyroidism. Prevalent vertebral fractures are only related to high serum PTH levels in female recipients.

Keywords

• Kidney transplant
• Vitamin D deficiency
• Persistent hyperparathyroidism
• Vertebral fractures
• Vascular calcifications
• Cyclosporin A
• Tacrolimus