Progression of aortic valve stenosis is associated with bone remodelling and secondary hyperparathyroidism in elderly patients—the COFRASA study

Serum levels of calcium, phosphorus, creatinine, 25-OH vitamin D, intact parathyroid hormon (iPTH), C-terminal- telopeptide of type-1-collagen (CTX) and osteocalcin were assessed at baseline in 110 elderly patients (age ≥70 years) with at least mild AS. CTX/osteocalcin ratio was calculated as a marker of bone remodelling balance. AS se- verity was assessed at baseline and 1-year based on the mean gradient. Two-thirds of patients had low 25-OH vitamin D and 20% had secondary hyperparathyroidism. AS progression was not associated with age, glomerular filtration rate (GFR), calcium and phosphorus levels, calcium-phosphorus product, but significantly with iPTH, CTX/osteocal- cin and vitamin D status (all P , 0.01). There was no correlation between iPTH and CTX/osteocalcin (R ¼ 0.04, P ¼ 0.70) and AS progression was associated with CTX/osteocalcin (R ¼ 0.42, P ¼ 0.009), but not with iPTH (R ¼ 0.10, P ¼ 0.55) in patients with normal vitamin D levels, whereas it was associated with iPTH (R ¼ 0.47, P , 0.001) and not with CTX/osteocalcin (R ¼ 0.04, P ¼ 0.73) in those with low vitamin D levels, especially if mild renal insufficiency was present (R ¼ 0.61, P , 0.001). Conclusion In elderly patients with AS, we observed an association between AS progression and vitamin D, iPTH and CTX/ osteocalcin ratio and their respective influence varied according to the vitamin D status. In patients with normal vitamin D levels, AS progression was associated with a bone resorptive balance, whereas in patients with low vitamin D levels, AS progression was associated with iPTH and secondary hyperparathyroidism, especially if mild renal insufficiency was present. These findings may have important prognostic and therapeutic implications. Trial registration information: Clinicaltrials.gov identifier number: NCT00338676, funded by AP-HP, the COFRASA study.