We investigated possible changes of parameters of calcium metabolism induced by strontium ranelate (SR). Twenty-three patients with postmenopausal osteoporosis (PO) and 14 with primary hyperparathyroidism (PHPT) were studied while taking 2 g/day of SR. Women with PO and 10 healthy age-matched control women were also daily supplemented with 1,000 mg calcium and 800 IU vitamin D. All subjects were studied at baseline and after 7 and 30 days; PO women and controls were also investigated at 180 and 360 days of treatment. Serum ionized calcium (iCa), phosphate (sP), magnesium, creatinine, 25-hydroxycholecalciferol (25[OH]D), 1,25-dihydroxycholecalciferol (1,25[OH]2D), serum parathyroid hormone (PTH) were measured. In spot urine, we assessed calcium and phosphate over creatinine ratios (uCa/Cr, uP/Cr), calcium excretion (Ca ex) and renal phosphate threshold (TmP/GFR); in 24-h urine, calcium and magnesium over creatinine clearance ratios (CaCl/CrCl and MgCl/CrCl). In PO, SR administration was associated with a significant decrease of PTH and 1,25(OH)2D levels but an increase of sP (p <0.001). SR also significantly increased Ca/Cr, Ca ex, and TmP/GFR in spot urine and CaCl/CrCl in both spot and 24-h urine (p = 0.004 to 2D values. Also in PHPT, Ca ex and CaCl/CrCl of spot and 24-h urine, as TmP/GFR, significantly increased (all p <0.02). SR influenced the main parameters of calcium homeostasis, probably through the calcium-sensing receptor.
- Calcium sensing receptor
- Parathyroid hormone
- Strontium ranelate
- Urinary calcium
ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Endocrinology, Diabetes and Metabolism