Stewart A F, Adler M, Byers C M, Segre G V, Broadus A E
N Engl J Med. 1982 May 13;306(19):1136-40. doi: 10.1056/NEJM198205133061903.
Prolonged immobilization may result in hypercalcemia, hypercalciuria, and osteoporosis. Although bone resorption is central to this syndrome, the mechanism of resorption is uncertain. In particular, the role of systemic calcium-regulating hormones remains unclear. In 14 immobilized subjects we measured fasting calcium excretion, 24-hour urinary calcium excretion during restricted calcium intake, the renal phosphorus threshold, plasma 1,25-dihydroxyvitamin D, nephrogenous cyclic AMP, and immunoreactive parathyroid hormone. Mean serum calcium levels were normal, but fasting and 24-hour calcium excretion were markedly elevated (0.28 mg per deciliter of glomerular filtrate and 314 mg per 24 hours, respectively). The mean levels of serum phosphorus (4.8 mg per deciliter) and the renal phosphorus threshold (4.3 mg per deciliter) were elevated. Mean plasma 1,25-dihydroxyvitamin D was strikingly reduced (9.9 pg per milliliter), as were nephrogenous cyclic (0.64 nmol per deciliter of glomerular filtrate) and immunoreactive parathyroid hormone in both assays. These findings indicate that the parathyroid--1,25-dihydroxyvitamin D axis is suppressed in patients with immobilization-induced hypercalciuria, as would be predicted by a model of resorptive hypercalciuria.
长期制动可能导致高钙血症、高钙尿症和骨质疏松症。尽管骨吸收是该综合征的核心，但吸收机制尚不清楚。特别是，全身钙调节激素的作用仍不明确。我们对14名制动患者测量了空腹钙排泄量、限钙摄入期间的24小时尿钙排泄量、肾磷阈值、血浆1,25 - 二羟维生素D、肾源性环磷酸腺苷和免疫反应性甲状旁腺激素。平均血清钙水平正常，但空腹和24小时钙排泄量显著升高（分别为每分升肾小球滤过液0.28毫克和每24小时314毫克）。血清磷平均水平（每分升4.8毫克）和肾磷阈值（每分升4.3毫克）升高。平均血浆1,25 - 二羟维生素D显著降低（每毫升9.9皮克），两种检测中的肾源性环磷酸腺苷（每分升肾小球滤过液0.64纳摩尔）和免疫反应性甲状旁腺激素也降低。这些发现表明，制动诱导的高钙尿症患者的甲状旁腺 - 1,25 - 二羟维生素D轴受到抑制，这与吸收性高钙尿症模型的预测一致。
