Dursun N, Akin S, Dursun E, Sade I, Korkusuz F
Department of Physical Medicine and Rehabilitation, Kocaeli University Faculty of Medicine, Kocaeli, Turkey.
Osteoporos Int. 2006;17(5):651-5. doi: 10.1007/s00198-005-0029-2. Epub 2006 Mar 1.
Despite numerous studies on risk factors for osteoporosis the effect of breast-feeding on bone mineral density (BMD) is unclear. In this study our aim was to determine the influence of total duration of breast-feeding on BMD, and subsequent risk of osteoporosis.
A total of 1,486 postmenopausal women over the age of 40 were included in the study. Women with diseases or who were under drug treatments known to affect bone metabolism were excluded. The BMD of the lumbar spine and femoral neck were measured by dual-energy X-ray absorptiometry technique, using either the Norland XA-26 or Lunar DPX-IQ densitometers and were transferred to standard values. Patients were placed in groups of five with respect to the duration of their breast-feeding as never, 1-12 months, 12-24 months, 24-60 months, >60 months.
One-way ANOVA test showed a significant difference between the lumbar spine and femoral neck BMD of these groups of women (p<0.001, p<0.001). Post hoc Bonferroni correction revealed that both the lumbar spine and femoral neck BMD results of women with longer duration of total breast-feeding were significantly lower than those of women with less duration of total breast-feeding. In subsequent analysis other potential risk factors were also considered in a multiple linear stepwise regression model. Years since menopause (p<0.001), weight (p<0.001), total duration of breast-feeding (p<0.001), and body mass index (p=0.001) were found to be the most important predictors for lumbar spine BMD; and age (p<0.001), weight (p<0.001), years since menopause (p<0.001), and total duration of breast-feeding (p<0.001) for femoral neck BMD.
This study showed significant associations between total duration of breast-feeding and BMD. In conclusion, total duration of breast-feeding might be an important risk factor besides age, weight, and years since menopause in postmenopausal osteoporosis.
尽管针对骨质疏松症的风险因素进行了大量研究，但母乳喂养对骨密度（BMD）的影响仍不明确。在本研究中，我们的目的是确定母乳喂养的总时长对骨密度以及随后骨质疏松症风险的影响。
共有1486名40岁以上的绝经后女性纳入本研究。排除患有已知会影响骨代谢的疾病或正在接受药物治疗的女性。使用Norland XA - 26或Lunar DPX - IQ骨密度仪，通过双能X线吸收测定技术测量腰椎和股骨颈的骨密度，并转换为标准值。根据母乳喂养时长，将患者分为五组：从未母乳喂养、1 - 12个月、12 - 24个月、24 - 60个月、>60个月。
单因素方差分析显示，这些女性组的腰椎和股骨颈骨密度之间存在显著差异（p<0.001，p<0.001）。事后Bonferroni校正显示，母乳喂养总时长较长的女性的腰椎和股骨颈骨密度结果均显著低于母乳喂养总时长较短的女性。在后续分析中，还在多元线性逐步回归模型中考虑了其他潜在风险因素。绝经年限（p<0.001）、体重（p<0.001）、母乳喂养总时长（p<0.001）和体重指数（p = 0.001）被发现是腰椎骨密度的最重要预测因素；而年龄（p<0.001）、体重（p<0.001）、绝经年限（p<0.001）和母乳喂养总时长（p<0.001）是股骨颈骨密度的最重要预测因素。
本研究表明母乳喂养总时长与骨密度之间存在显著关联。总之，母乳喂养总时长可能是绝经后骨质疏松症中除年龄、体重和绝经年限之外的一个重要风险因素。
