Rejnmark L, Mosekilde L, Andreasen F
Klinisk Farmakologisk Center, Arhus Universitet.
Nord Med. 1998 Feb;113(2):53-9.
Thiazide diuretics lower while loop diuretics promote calcium excretion by the kidney. Several studies have found thiazide use to be associated with higher bone mineral density and some have found that thiazides reduce the risk of hip fracture. The mechanisms by which thiazides favour preservation of the bones are uncertain. Thiazide use results in decreased renal calcium excretion and thiazide users have been shown to have lower levels of S-PTH and S-1,25-dihydroxy-vitamin D. The beneficial bone effects may result from a decrease in PTH-stimulated bone resorption and an associated reduction in the bone turn-over rate. Whether loop diuretics increases the bone turn-over by augmenting the urinary calcium excretion is more controversial as only few studies have been carried out on loop diuretics. However, in these studies the use of loop diuretics have been associated with decreased bone mineral density and increased risk of fractures. Future research should determine the minimal dose of thiazide therapy necessary to produce a sustained hypocalciuric effect and in addition the influence of diuretic dose on bone turn-over. Equally important is the need to evaluate potential unwanted effects of loop diuretics. In the mean time, thiazide diuretics may be used safely while some caution is necessary in the long term use of loop diuretics in patients who are prone to osteoporosis.
噻嗪类利尿剂可降低血钙水平，而袢利尿剂则促进肾脏排钙。多项研究发现，使用噻嗪类药物与较高的骨矿物质密度相关，一些研究还发现噻嗪类药物可降低髋部骨折风险。噻嗪类药物有利于骨骼保护的机制尚不清楚。使用噻嗪类药物会导致肾脏钙排泄减少，且已证明使用噻嗪类药物的患者血清甲状旁腺激素（S-PTH）和血清1,25-二羟维生素D水平较低。其对骨骼的有益作用可能源于甲状旁腺激素刺激的骨吸收减少以及骨转换率相应降低。袢利尿剂是否通过增加尿钙排泄来提高骨转换率更具争议性，因为针对袢利尿剂的研究较少。然而，在这些研究中，使用袢利尿剂与骨矿物质密度降低和骨折风险增加有关。未来的研究应确定产生持续低钙尿作用所需的噻嗪类治疗最小剂量，此外还应研究利尿剂剂量对骨转换的影响。同样重要的是，需要评估袢利尿剂的潜在不良影响。与此同时，噻嗪类利尿剂可安全使用，而对于易患骨质疏松症的患者，长期使用袢利尿剂时则需要谨慎。
