Division of Preventive Medicine, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan.
Department of Health and Nutrition, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata City, 951-3198, Japan.
Arch Osteoporos. 2019 Feb 8;14(1):17. doi: 10.1007/s11657-019-0575-4.
We aimed to determine whether the effect of calcium supplements on bone metabolism is modified by physical activity (PA) through a subgroup analysis of an RCT. PA may be a favorable effect modifier of the association between calcium intake and bone loss in perimenopausal and postmenopausal women.
Physical exercise can potentially modify bone metabolism. Here we aimed to determine whether the effect of calcium supplements on bone metabolism is modified by physical activity (PA) through a subgroup analysis of a randomized, double-blind, placebo-controlled trial.
The trial was conducted over the course of 2 years, and participants were 450 healthy women between 50 and 75 years of age who were randomly assigned to three equally-sized (N = 150 each) groups (500 mg calcium, 250 mg calcium, and placebo). Levels of PA at baseline were evaluated by quantifying moderate (4 METs) and vigorous (6 METs) activities based on a 7-day activity recall, and the total MET-hours per week was calculated. Follow-up BMD examinations were conducted 2 years later. Two-year changes in BMD were compared between the intention-to-treat higher PA subgroup (≥ 10 MET-hours/week) and the lower PA subgroup (< 10 MET-hours/week).
Of the 450 participants, 418 underwent follow-up BMD measurements. Regarding the lower PA subgroup, spinal BMD in the 500 mg/day calcium supplement group decreased significantly less (- 0.029 g/cm, P = 0.042) than in the placebo group (- 0.045 g/cm), and femoral neck BMD in the 500 mg/day calcium supplement group decreased significantly less (- 0.027 g/cm, P = 0.049) than in the placebo group (- 0.038 g/cm). In contrast, changes in neither spinal nor femoral neck BMD significantly differed between the three treatment groups in the higher PA subgroup.
PA is a favorable effect modifier of the association between calcium intake and bone loss in perimenopausal and postmenopausal women with low calcium intake.
UMIN000001176.
本研究旨在通过一项随机、双盲、安慰剂对照试验的亚组分析，确定体力活动（PA）是否会改变钙补充剂对骨代谢的影响。
该试验持续 2 年，共有 450 名年龄在 50 至 75 岁之间的健康女性参与，她们被随机分为三组（每组 150 人）：500mg 钙组、250mg 钙组和安慰剂组。在基线时，通过量化基于 7 天活动回忆的中度（4 MET）和剧烈（6 MET）活动，评估 PA 水平，并计算每周总 MET 小时数。2 年后进行随访 BMD 检查。比较意向治疗更高 PA 亚组（≥10 MET-hours/week）和较低 PA 亚组（<10 MET-hours/week）之间的 2 年 BMD 变化。
在 450 名参与者中，有 418 名完成了随访 BMD 测量。对于低 PA 亚组，500mg/天钙补充组的脊柱 BMD 下降幅度明显小于安慰剂组（-0.029 g/cm，P=0.042），500mg/天钙补充组的股骨颈 BMD 下降幅度明显小于安慰剂组（-0.027 g/cm，P=0.049）。相比之下，在高 PA 亚组中，三个治疗组之间的脊柱和股骨颈 BMD 变化均无显著差异。
PA 是低钙摄入的绝经前后妇女钙摄入量与骨丢失之间关联的有利效应修饰剂。
UMIN000001176。
