Loop diuretics alter the diurnal rhythm of endogenous parathyroid hormone secretion. A randomized‐controlled study on the effects of loop‐ and thiazide‐diuretics on the diurnal rhythms of calcitropic hormones and biochemical bone markers in postmenopausal women

摘要: Background Thiazide diuretics (TD) reduce urinary calcium, bone loss and fracture risk. Loop (LD) may have opposite effects. These effects could depend on induced rhythmic changes in calcium homeostasis. Design After a run-in period of 7 days, we studied (in factorial design) the diurnal rhythms plasma levels phosphate, parathyroid hormone (PTH), 1,25-dihydroxyvitamin D osteocalcin, as well renal excretions rates cross-linked N-terminal telopeptide type 1 collagen (NTx) 50 postmenopausal women randomized to treatment with either thiazide diuretic (TD; bendroflumethiazide, n = 14), loop (LD; bumetanide, n = 13), LD plus TD (bendroflumethiazide n = 11), or placebo (n = 12). Results In all four groups, measured quantities showed variation. caused steep increase, subsequent decrease, PTH. The mean 24 h PTH concentration was increased (8·5 ± 0·9 mmol L−1) compared (4·4 ± 0·4 mmol L−1), whereas net excretion did not differ from that group due rebound hypocalciuria. Compared placebo, phosphate osteocalcin were changed an increase during daytime decrease night. alter rhythm any quantities. However, 24-h decreased, without suppression. similar those observed alone. Conclusion One daily dose increases activity alterations pattern osteocalcin. This indicate potential anabolic effect LD.