Riggs B L, O'Fallon W M, Muhs J, O'Connor M K, Kumar R, Melton L J
Division of Endocrinology and Metabolism, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
J Bone Miner Res. 1998 Feb;13(2):168-74. doi: 10.1359/jbmr.1998.13.2.168.
We report a 4-year randomized, double-blind, placebo-controlled clinical trial in 236 normal postmenopausal women (mean age +/- SE, 66.3+/-0.2 years) who were randomized to a calcium (1600 mg/day as the citrate) or placebo group. The women were seen every 6 months; 177 completed the trial. Net percentage changes in each group are given relative to baseline. The differences in net percentage changes (calcium group minus placebo group) in medians were: for lumbar spine bone density, 2.0% (p < 0.001) at year 1 and 0.3% (not significant) at year 4; for proximal femur bone density, 1.3% (p = 0.003) at year 1 and 1.3% (p = 0.015) at year 4; and for total body bone mineral, 0.4% (p = 0.002) at year 1 and 0.9% (p = 0.017) at year 4. Similar differences at year 4 were: -18.9% (p = 0.002) for parathyroid hormone (PTH), -11.9% (p = 0.026) for serum osteocalcin, and -32.2% (p = 0.003) for urine free pyridinoline. We conclude that long-term administration of calcium supplements to elderly women partially reverses age-related increases in serum PTH level and bone resorption and decreases bone loss. However, the effects on bone loss were weaker than those reported for estrogen, bisphosphonates, or calcitonin therapy, indicating that calcium supplements alone cannot substitute for these in treating established osteoporosis. Nonetheless, because of their safety, high tolerance, and low expense, calcium supplements may be a useful preventive measure for elderly postmenopausal women whose bone mineral density values are normal for their age.
我们报告了一项针对236名正常绝经后女性（平均年龄±标准误，66.3±0.2岁）的为期4年的随机、双盲、安慰剂对照临床试验，这些女性被随机分为钙（1600毫克/天，枸橼酸盐形式）组或安慰剂组。每6个月对这些女性进行一次检查；177名女性完成了试验。每组的净百分比变化均相对于基线给出。中位数净百分比变化（钙组减去安慰剂组）的差异如下：对于腰椎骨密度，第1年为2.0%（p<0.001），第4年为0.3%（无显著性差异）；对于股骨近端骨密度，第1年为1.3%（p = 0.003），第4年为1.3%（p = 0.015）；对于全身骨矿物质，第1年为0.4%（p = 0.002），第4年为0.9%（p = 0.017）。第4年时类似的差异为：甲状旁腺激素（PTH）为-18.9%（p = 0.002），血清骨钙素为-11.9%（p = 0.026），尿游离吡啶啉为-32.2%（p = 0.003）。我们得出结论，对老年女性长期补充钙剂可部分逆转与年龄相关的血清PTH水平升高和骨吸收增加，并减少骨质流失。然而，其对骨质流失的影响弱于雌激素、双膦酸盐或降钙素治疗的报道，这表明单独补充钙剂不能替代这些药物治疗已确诊的骨质疏松症。尽管如此，由于钙剂安全性高、耐受性好且费用低廉，对于骨矿物质密度值在其年龄正常范围内的老年绝经后女性，补充钙剂可能是一种有用的预防措施。
