UCD Perinatal Research Centre, School of Medicine, University College Dublin, National Maternity Hospital, Dublin, Ireland.
Department of Clinical Chemistry, St Vincent's University Hospital, Dublin, Ireland.
Osteoporos Int. 2021 Sep;32(9):1803-1814. doi: 10.1007/s00198-021-05891-w. Epub 2021 Mar 4.
Pregnancy is characterized by increased bone turnover and reversible loss of bone mineral density (BMD) to meet fetal calcium demands. The long-term effect of bone turnover and maternal diet in pregnancy on maternal bone is not well established.
We aimed to determine if an association exists between [1] bone resorption, [2] dietary calcium, and [3] serum 25-hydroxyvitamin D in pregnancy with maternal BMD 5-year postpartum.
This is a prospective, longitudinal study of 107 women recruited to the ROLO low glycemic index dietary intervention trial in pregnancy and followed-up at 13, 28, and 34 weeks' gestation and 5 years' postpartum. At 13 and 28 weeks' gestation, a biomarker of bone resorption, urine cross-linked N-telopeptide of type I collagen (uNTX), was measured. At the 5-year follow-up BMD was measured using dual-energy X-ray absorptiometry. Anthropometry, dietary intakes, and serum 25-hydroxyvitamin D were measured in pregnancy and at 5 years. Multiple linear regression, controlling for confounders, was used for analysis.
Mean BMD at 5 years was 1.208 g/cm. In pregnancy, 24-34% reported dietary calcium intakes <800 mg/day. Vitamin D deficiency (< 30 nmol/L) was observed in 38-41% of women in pregnancy and in 29% of women at the 5-year follow-up. At 13 and 28 weeks' gestation, uNTX levels greater than the median were associated with 0.060 and 0.050 g/cm lower BMD 5 years later, respectively. Dietary calcium <800 mg/day in trimester 3 was associated with 0.072 g/cm lower BMD 5 years later. Vitamin D deficiency at 5 years, but not in pregnancy, was associated with lower BMD.
Higher bone resorption and low dietary calcium in pregnancy were associated with lower BMD 5 years later. These findings could enable the identification of women at risk of declining of BMD in later life, but further research is needed. Adequate dietary calcium should be advised in the antenatal setting to promote lifelong maternal bone health.
妊娠期间，骨转换增加，骨密度（BMD）可逆性下降，以满足胎儿对钙的需求。骨转换和妊娠期间母体饮食对母体骨的长期影响尚未得到充分证实。
我们旨在确定妊娠期间[1]骨吸收、[2]膳食钙和[3]血清 25-羟维生素 D 与产后 5 年时的母体 BMD 是否存在关联。
这是一项前瞻性、纵向研究，共招募了 107 名女性参加 ROLO 低血糖指数饮食干预试验，并在妊娠 13、28 和 34 周以及产后 5 年进行随访。在妊娠 13 周和 28 周时，测量了尿Ⅰ型胶原交联 N-末端肽（uNTX）这一骨吸收的生物标志物。在 5 年随访时，使用双能 X 线吸收法测量 BMD。在妊娠期间和 5 年后测量了人体测量学、膳食摄入量和血清 25-羟维生素 D。采用多元线性回归分析，控制混杂因素。
产后 5 年时的平均 BMD 为 1.208 g/cm。妊娠期间，有 24%-34%的女性报告膳食钙摄入量<800mg/天。妊娠期间有 38%-41%的女性维生素 D 缺乏（<30 nmol/L），而在产后 5 年随访时，这一比例为 29%。在妊娠 13 周和 28 周时，uNTX 水平高于中位数与 5 年后 BMD 分别降低 0.060 和 0.050 g/cm 相关。妊娠晚期膳食钙<800mg/天与 5 年后 BMD 降低 0.072 g/cm 相关。产后 5 年时的维生素 D 缺乏与 BMD 降低相关，但妊娠期间的维生素 D 缺乏与 BMD 降低无关。
妊娠期间骨吸收增加和膳食钙摄入不足与 5 年后 BMD 降低相关。这些发现可以帮助识别日后 BMD 下降风险较高的女性，但还需要进一步研究。在产前阶段应建议摄入足够的膳食钙，以促进母体骨骼的终生健康。
