Institute of Medical Biometry and Epidemiology (IMBE), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany.
Institute of Neuroimmunology and Multiple Sclerosis (INIMS), Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany.
Neuroepidemiology. 2022;56(6):391-401. doi: 10.1159/000526895. Epub 2022 Sep 12.
The causes of multiple sclerosis (MS) are not fully understood, yet. Genetic predisposition, environmental and lifestyle factors as well as an interplay thereof constitute relevant factors in the development of MS. Especially early-life risk factors such as having been breastfed may also be of relevance. Breast milk provides the newborn not only with essential nutrients and vitamins but also with numerous immune-active molecules, metabolites, oligosaccharides, and microbial components that are important for the development of the immune system. We present a systematic review and meta-analysis on the influence of having been breastfed during infancy on the risk of developing MS.
The databases MEDLINE, Cochrane Library, and Web of Science were systematically searched for studies on breastfeeding and MS published between database inception and May 18, 2022. Observational studies comparing persons with MS to healthy controls with regard to having been breastfed during the first 2 years of life were eligible for inclusion. A random effects meta-analysis was calculated to estimate pooled effect sizes using the Mantel-Haenszel method for dichotomous outcomes. The Newcastle-Ottawa Scale was used for quality analysis.
15 studies (13 case-control, 2 cohort) were included of which 12 were rated as high quality. The meta-analysis of crude odds ratios (ORs) yielded a risk estimate of ORcrude = 0.82 (95% confidence interval [CI]: 0.70-0.96) for MS in breastfed versus non-breastfed individuals with substantial heterogeneity (I2 = 68.2%). Using adjusted OR, when available, reduced heterogeneity (I2 = 48.9%) and resulted in an ORadjusted = 0.86 (95% CI: 0.75-0.99). Restricting the analysis to studies with high-quality scores (i.e., ≥6/9 points) resulted in a combined ORcrude of 0.79 (95% CI: 0.66-0.94) and an ORadjusted = 0.83 (95% CI: 0.71-0.98), respectively.
DISCUSSION/CONCLUSION: The meta-analysis showed a small protective effect of having been breastfed on MS risk. This adds to the knowledge that breastfeeding is beneficial for the immunological health of a child. Future studies on the influence of having been breastfed on MS risk should apply a uniform definition of breastfeeding and investigate possible sex-specific aspects.
多发性硬化症（MS）的病因尚未完全阐明。遗传易感性、环境和生活方式因素以及它们之间的相互作用是 MS 发展的相关因素。特别是婴儿期的早期风险因素，如母乳喂养，也可能与之相关。母乳不仅为新生儿提供了必需的营养和维生素，还提供了许多免疫活性分子、代谢物、低聚糖和微生物成分，这些对免疫系统的发育很重要。我们对婴儿期母乳喂养对 MS 发病风险的影响进行了系统回顾和荟萃分析。
系统检索了 MEDLINE、Cochrane 图书馆和 Web of Science 数据库，以获取截至 2022 年 5 月 18 日发表的关于母乳喂养和 MS 的研究。符合纳入标准的研究为比较 MS 患者与健康对照组在生命的头 2 年是否母乳喂养的观察性研究。使用 Mantel-Haenszel 法计算二分类结局的合并效应大小，采用随机效应模型进行荟萃分析。纽卡斯尔-渥太华量表用于质量分析。
共纳入 15 项研究（13 项病例对照，2 项队列研究），其中 12 项研究质量评价为高。荟萃分析粗比值比（OR）显示，母乳喂养与非母乳喂养者相比，MS 的风险估计值为 ORcrude=0.82（95%置信区间[CI]：0.70-0.96），存在较大异质性（I2=68.2%）。使用可用的调整 OR 可降低异质性（I2=48.9%），并得到 ORadjusted=0.86（95%CI：0.75-0.99）。将分析仅限于高质量评分（即≥6/9 分）的研究，得到合并的 ORcrude 为 0.79（95%CI：0.66-0.94），ORadjusted=0.83（95%CI：0.71-0.98）。
讨论/结论：荟萃分析显示，母乳喂养对 MS 风险有较小的保护作用。这增加了母乳喂养对儿童免疫健康有益的知识。未来关于母乳喂养对 MS 风险影响的研究应采用统一的母乳喂养定义，并调查可能的性别特异性方面。
