Bianchetti M G, Bettinelli A, Casez J P, Basilico E, Metta M G, Spicher I, Santeramo C, Bigoni M, Jaeger P
Abteilung für Nephrologie, Universitätskinderklinik, Bern, Switzerland.
J Clin Endocrinol Metab. 1995 Jan;80(1):224-8. doi: 10.1210/jcem.80.1.7829616.
Little attention has been paid to interactions between circulating levels of calcium, PTH, and 1,25-dihydroxycholecalciferol [1,25(OH)2D] and bone mineral density in primary renal magnesium deficiency. Plasma and urinary electrolytes, and circulating levels of calciotropic hormones were studied in 13 untreated patients with primary renal tubular hypokalemic alkalosis with hypocalciuria and magnesium deficiency. The blood ionized calcium concentration was significantly lower in patients than in controls. Despite this fact, PTH and 1,25-(OH)2D levels were similar in both groups of subjects. The negative linear relationships between PTH and ionized calcium, which significantly differed between Gitelman patients and healthy subjects in terms of intercept; the negative relationship between ionized calcium and 1,25-(OH)2D, which was comparable in both groups; and the positive relationship between 1,25-(OH)2D and PTH, which was identical in both groups, point both to a blunted secretion of PTH induced by magnesium depletion and to the lack of interference of the latter with the activation of 1 alpha-hydroxylase by PTH. The similar bone mineral density at the lumbar spine by dual energy x-ray absorptiometry in 11 patients and 11 healthy subjects argues against chronically sustained negative calcium balance.
在原发性肾性镁缺乏症中，循环钙水平、甲状旁腺激素（PTH）和1,25 - 二羟胆钙化醇[1,25(OH)₂D]之间的相互作用以及骨矿物质密度很少受到关注。对13例未经治疗的原发性肾小管性低钾性碱中毒伴低钙尿症和镁缺乏症患者的血浆和尿液电解质以及钙调节激素的循环水平进行了研究。患者的血离子钙浓度显著低于对照组。尽管如此，两组受试者的PTH和1,25-(OH)₂D水平相似。PTH与离子钙之间的负线性关系在吉特曼综合征患者和健康受试者之间的截距有显著差异；离子钙与1,25-(OH)₂D之间的负相关关系在两组中相当；1,25-(OH)₂D与PTH之间的正相关关系在两组中相同，这既表明镁缺乏诱导PTH分泌减弱，也表明镁缺乏对PTH激活1α - 羟化酶没有干扰。通过双能X线吸收法测定的11例患者和11例健康受试者腰椎的骨矿物质密度相似，这与长期持续的负钙平衡相矛盾。
