Laskey M A, Prentice A
MRC Human Nutrition Research, Cambridge, United Kingdom.
Obstet Gynecol. 1999 Oct;94(4):608-15. doi: 10.1016/s0029-7844(99)00369-5.
To assess bone mineral changes during and after lactation.
Fifty-nine breast-feeding women, 11 formula-feeding women, and 22 nonpregnant, nonlactating women had dual-energy x-ray absorptiometry measurements of the whole body, spine, hip, and forearm at 0.5 (baseline), 3, 6, and 12 months postpartum, with an additional measurement at 3 months after lactation for women who had breast-fed for more than 9 months.
Lactation was associated with decreases in bone mineral at the whole body, spine, femoral neck, total hip, and radial wrist, which reversed as lactation declined and menstruation resumed. These changes were not seen in formula-feeding women. The magnitude and duration of the response were greater for women who breast-fed for a longer time. After lactation had stopped for at least 3 months, bone mineral, adjusted for bone area, had increased significantly above baseline at the whole body (+1.44%; 95% confidence interval [CI] +0.97%, +1.91%; P < .001), spine (+2.66%; 95% CI +1.60%, +3.72%; P < .001), and greater trochanter (+3.55%; 95% CI +2.53%, +4.57%; P < .001), was not different at the total hip and radial shaft, but was lower at the femoral neck (-2.07%; 95% CI -3.21%, -0.93%; P < .001) and radial wrist (-1.23%; 95% CI -1.99%, -0.47%; P < .01). Changes after lactation were largely independent of the duration of lactation or amenorrhea, and similar effects were observed in formula-feeding women.
Lactation was associated with temporary decreases in bone mineral. After lactation, there were significant residual effects on bone mineral that were unrelated to the duration of lactation and may be related to having been pregnant. The long-term effect of lactation on the femoral neck requires further investigation.
评估哺乳期及哺乳期后的骨矿物质变化。
59名母乳喂养女性、11名配方奶喂养女性和22名非孕非哺乳期女性在产后0.5个月（基线）、3个月、6个月和12个月时接受了全身、脊柱、髋部和前臂的双能X线吸收测定，对于母乳喂养超过9个月的女性，在哺乳期结束后3个月时进行了额外测量。
哺乳期与全身、脊柱、股骨颈、全髋和桡骨腕部的骨矿物质减少有关，随着哺乳期结束和月经恢复，这些变化会逆转。配方奶喂养女性未出现这些变化。母乳喂养时间较长的女性，其反应的幅度和持续时间更大。在哺乳期停止至少3个月后，经骨面积调整后的骨矿物质在全身（+1.44%；95%置信区间[CI]+0.97%，+1.91%；P<.001）、脊柱（+2.66%；95%CI+1.60%，+3.72%；P<.001）和大转子（+3.55%；95%CI+2.53%，+4.57%；P<.001）显著高于基线水平，在全髋和桡骨干处无差异，但在股骨颈处较低（-2.07%；95%CI-3.21%，-0.93%；P<.001），在桡骨腕部也较低（-1.23%；95%CI-1.99%，-0.47%；P<.01）。哺乳期后的变化在很大程度上与哺乳期或闭经的持续时间无关，在配方奶喂养女性中也观察到了类似的影响。
哺乳期与骨矿物质的暂时减少有关。哺乳期后，对骨矿物质有显著的残留影响，这些影响与哺乳期持续时间无关，可能与怀孕有关。哺乳期对股骨颈的长期影响需要进一步研究。
