PREVENTION OF AGE-RELATED BONE LOSS WITH CALCIUM THERAPY

该项目包括一项正在进行的4年前瞻性、双重约束、安慰剂- 236例老年人补钙的临床对照研究 入境时年龄在61至70岁之间， 绝经后 临床试验是独一无二的，因为它是基于人群的， 参与者是通过筛选这个年龄组的人来获得的。 Olmsted County，MN的所有居民。提交时， 据估计，这将需要长达2年的筛选3,013潜在的 合格的妇女和招募参与者参加试验， 完成这项工作需要延期。事实证明， 我们申请延期一年。 核心假设是 这项试验的基础是， 老年妇女是钙补充剂。 我们的主要研究目标是 确定钙补充剂对骨丢失的影响，我们的第二个 研究的目的是确定这是否与减少 甲状旁腺功能和骨转换，并确定副作用， 这些老年妇女中钙补充剂的患者可接受性。 的 参与者被随机分为治疗组和对照组;受试者 在接受1，600 mg/天Ca（柠檬酸钙）的治疗肢体中， 在对照肢体中接受了匹配的安慰剂。 受试者 在基线时进行评估，并在治疗期间每6个月观察一次， 治疗依从性评估和骨密度测量 （腰椎、股骨近端和整个骨骼） 骨吸收测定法，骨转换的生化标志物（血清骨钙素， 骨碱性磷酸酶和尿吡啶鎓交联），以及 甲状旁腺功能（血清全段甲状旁腺激素和尿 cAMP）。 重要的是要完成完整的4年试验， 有足够的统计能力来明确地解决中心问题 而且，由于一些研究表明， 1年后，以确定任何有益的效果是长期保持- term. 考虑到退化问题的巨大规模 对于骨质疏松症，唯一具有成本效益的方法是预防。 干预 补充钙是一个有吸引力的选择，因为，相比之下， 其他可用的药物用于预防骨质流失，它是相对 廉价和安全，以及大规模干预策略，如Ca 强化食品，可以使用。 然而，在这种全国性的 可以推荐的方案，更明确和严格的数据应该是 获得支持长期有效性和安全性，例如 来自于这个临床试验。

This project comprises an ongoing 4-year prospective, double-bind, placebo- controlled clinical trial of calcium (Ca) supplementation in 236 elderly women who were 61 to 70 yrs of age at entry and at least 10 yrs postmenopausal. The clinical trial is unique as it is population-based, and the participants were obtained by screening this age-group in the entire population of Olmsted County, MN. At the time of submission, it was estimated that it would take up to 2 yrs to screen the 3,013 potentially eligible women and recruit participants into the trial and that an extension would be required to complete it. This has proved to be the case, and we are requesting a 1-yr extension. The central hypothesis upon which the trial is based is that a major etiologic factor for bone loss in elderly women is Ca supplementation. Our primary study objective is to determine the effect of Ca supplementation on bone loss, and our secondary study objectives are to determine if this is associated with a decrease in parathyroid function and in bone turnover and to determine side effects and patient acceptability of Ca supplementation in these elderly women. The participants were randomized into treatment and control limbs; the subjects in the treatment limb received 1,600 mg/day of Ca (as Ca citrate) and those in the control limb received a matching placebo. The subjects were evaluated at baseline and are seen every 6 months during treatment for assessment of therapeutic compliance and measurement of bone density (lumbar spine, proximal femur, and whole skeleton) by dual photon absorptiometry, biochemical markers for bone turnover (serum osteocalcin, bone alkaline phosphatase, and urinary pyridinium cross-links), and parathyroid gland function (serum intact parathyroid hormone and urinary cAMP). It is important to complete the full 4 yrs of the trial to have sufficient statistical power to resolve the central issue unequivocally and, because some studies have suggested a waning of the therapeutic effect after 1 yr, to establish that any beneficial effect is maintained long- term. Given the enormous magnitude of the problem of involutional osteoporosis, the only cost-effective approach is prevention. Intervention with Ca supplementation is an attractive option because, in contrast with other available drugs for the prevention of bone loss, it is relatively inexpensive and safe, and mass interventive strategies, such as Ca fortification of food, could be employed. However, before such nation-wide programs could be recommended, more definitive and rigorous data should be obtained supporting long-term efficacy and safety, such as those to be derived from this clinical trial.