School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia.
Medical School, University of Western Australia, Perth, Australia.
Osteoporos Int. 2019 Oct;30(10):2065-2072. doi: 10.1007/s00198-019-05087-3. Epub 2019 Jul 24.
One year of calcium supplementation in older women led to modest reductions in total osteocalcin and undercarboxylated osteocalcin (ucOC), with no changes in muscle or fat mass, or glycated haemoglobin. Future studies should explore whether treatments with more profound effects of suppressing ucOC may lead to impaired glycaemic control.
Total osteocalcin (TOC) is a marker of bone turnover, while its undercarboxylated form has beneficial effects on glucose metabolism in mice. This post hoc analysis of a randomised double-blind, placebo-controlled trial examined whether 1 year of calcium supplementation affected circulating TOC, undercarboxylated osteocalcin (ucOC) or glycated haemoglobin (HbA1c) in 1368 older community-dwelling women (mean age 75.2 ± 2.7 years).
Women enrolled in the Calcium Intake Fracture Outcome Study trial (1998-2003) were supplemented with 1.2 g/d of elemental calcium (in the form of calcium carbonate) or placebo. Circulating TOC, ucOC and HbA1c was measured at 1 year (1999).
After 1 year of calcium supplementation, TOC and ucOC levels were 17% and 22% lower compared with placebo (mean 22.7 ± 9.1 vs. 27.3 ± 10.9 μg/L and 11.1 ± 4.9 vs. 13.0 ± 5.7 μg/L, both P < 0.001). Carboxylated osteocalcin/ucOC was 6% lower after calcium supplementation (P < 0.05). Despite this, no differences in HbA1c were observed (calcium, 5.2 ± 0.6 vs. placebo, 5.3 ± 0.8%; P = 0.08). Calcium supplementation did not affect BMI, whole body lean or fat mass. In exploratory analyses, total calcium (dietary and supplemental) was inversely related to TOC and ucOC, indicating calcium intake is an important dietary determinant of osteocalcin levels.
One year of calcium supplementation in older women led to modest reductions in TOC and ucOC, with no changes in muscle or fat mass, or HbA1c. Future studies should explore whether treatments with more profound effects of suppressing ucOC may lead to impaired glycaemic control.
在老年女性中进行为期一年的钙补充后，总骨钙素和非羧化骨钙素（ucOC）略有下降，肌肉或脂肪量或糖化血红蛋白无变化。未来的研究应该探讨是否具有更显著抑制 ucOC 作用的治疗方法可能导致血糖控制受损。
总骨钙素（TOC）是骨转换的标志物，而其未羧化形式对小鼠的葡萄糖代谢有有益影响。这项随机双盲、安慰剂对照试验的事后分析检查了在 1368 名年龄在 75.2±2.7 岁的社区居住的老年女性中，为期一年的钙补充是否会影响循环 TOC、非羧化骨钙素（ucOC）或糖化血红蛋白（HbA1c）（1998-2003 年参加钙摄入量骨折结局研究试验）。
女性接受 1.2 克/天的元素钙（碳酸钙形式）或安慰剂补充。1 年后（1999 年）测量循环 TOC、ucOC 和 HbA1c。
与安慰剂相比，1 年后钙补充组的 TOC 和 ucOC 水平分别降低了 17%和 22%（均值 22.7±9.1 与 27.3±10.9μg/L 和 11.1±4.9 与 13.0±5.7μg/L，均 P<0.001）。钙补充后羧化骨钙素/ucOC 降低了 6%（P<0.05）。尽管如此，HbA1c 没有差异（钙，5.2±0.6 与安慰剂，5.3±0.8%；P=0.08）。钙补充对 BMI、全身瘦体重或脂肪量没有影响。在探索性分析中，总钙（饮食和补充）与 TOC 和 ucOC 呈负相关，表明钙摄入量是骨钙素水平的重要饮食决定因素。
在老年女性中进行为期一年的钙补充后，总骨钙素和非羧化骨钙素略有下降，肌肉或脂肪量或糖化血红蛋白无变化。未来的研究应该探讨是否具有更显著抑制 ucOC 作用的治疗方法可能导致血糖控制受损。
