School of Demography, The Australian National University, Canberra, Australia.
MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
PLoS Med. 2019 Aug 27;16(8):e1002889. doi: 10.1371/journal.pmed.1002889. eCollection 2019 Aug.
Evidence on the association between breastfeeding and later childhood obesity and blood pressure (BP) is inconsistent, especially in HIV-prevalent areas where, until recently, HIV-infected women were discouraged from breastfeeding, but obesity is increasingly prevalent.
The Siyakhula cohort (2012-2014), a population-based prospective cohort study, collected data over 3 visits on HIV-negative children ages 7 to 11 years in rural South Africa. We used weight (body mass index [BMI]), fat, and BP as outcome variables and incorporated early life (including mother's age at delivery and HIV status) and current life factors (including maternal education and current BMI). Our primary exposure was breastfeeding duration. We dichotomized 3 outcome measures using pre-established thresholds for clinical interpretability: (1) overfat: ≥85th percentile of body fat; (2) overweight: >1 SD BMI z score; and (3) prehypertension: ≥90th percentile for systolic BP (SBP) or diastolic BP (DBP). We modelled each outcome using multivariable logistic regression, including stopping breastfeeding, then early life, and finally current life factors. Of 1,536 children (mean age = 9.3 years; 872 girls; 664 boys), 7% were overfat, 13.2% overweight, and 9.1% prehypertensive. Over half (60%) of the mothers reported continued breastfeeding for 12+ months. In multivariable analyses, continued breastfeeding between 6 and 11 months was associated with approximately halved odds of both being overfat (adjusted odds ratio [aOR] = 0.43, 95% confidence interval [CI] 0.21-0.91, P = 0.027) and overweight (aOR = 0.46, CI 0.26-0.82, P = 0.0083), but the association with prehypertension did not reach statistical significance (aOR = 0.72, CI 0.38-1.37, P = 0.32). Children with a mother who was currently obese were 5 times more likely (aOR = 5.02, CI 2.47-10.20, P < 0.001) to be overfat and over 4 times more likely to be overweight (aOR = 4.33, CI 2.65-7.09, P < 0.001) than children with normal weight mothers. Differences between HIV-exposed and unexposed children on any of the outcomes were minimal and not significant. The main study limitation was that duration of breastfeeding was based on maternal recall.
To our knowledge, this is the first study examining and quantifying the association between breastfeeding and childhood obesity in an African setting with high HIV prevalence. We observed that breastfeeding was independently associated with reduced childhood obesity for both HIV-exposed and unexposed children, suggesting that promoting optimal nutrition throughout the life course, starting with continued breastfeeding, may be critical to tackling the growing obesity epidemic. In the era of widespread effective antiretroviral treatment for HIV-infected women for life, these data further support the recommendation of breastfeeding for all women.
有关母乳喂养与儿童后期肥胖和血压（BP）之间关联的证据不一致，尤其是在 HIV 流行地区，直到最近，HIV 感染的妇女都被劝阻进行母乳喂养，但肥胖症的发病率却越来越高。
Siyakhula 队列（2012-2014 年）是一项基于人群的前瞻性队列研究，在南非农村地区收集了 7 至 11 岁 HIV 阴性儿童的 3 次访问数据。我们使用体重（体重指数 [BMI]）、脂肪和 BP 作为结果变量，并纳入了早期生命（包括母亲的分娩年龄和 HIV 状况）和当前生命因素（包括母亲的教育程度和当前 BMI）。我们的主要暴露是母乳喂养时间。我们使用预先确定的临床可解释性阈值将 3 个结果指标分为两类：（1）超重：体脂肪≥第 85 百分位；（2）超重：BMI z 分数>1 SD；（3）前期高血压：收缩压（SBP）或舒张压（DBP）≥第 90 百分位。我们使用多变量逻辑回归模型来对每个结果进行建模，包括停止母乳喂养，然后是早期生命，最后是当前生命因素。在 1536 名儿童（平均年龄=9.3 岁；872 名女孩；664 名男孩）中，7%的儿童超重，13.2%的儿童超重，9.1%的儿童前期高血压。超过一半（60%）的母亲报告持续母乳喂养 12 个月以上。在多变量分析中，6 至 11 个月的持续母乳喂养与超重的几率降低约一半相关（调整后的比值比[aOR]=0.43，95%置信区间[CI]0.21-0.91，P=0.027）和超重（aOR=0.46，CI 0.26-0.82，P=0.0083），但与前期高血压的关联无统计学意义（aOR=0.72，CI 0.38-1.37，P=0.32）。目前肥胖母亲的孩子超重的可能性是体重正常母亲的孩子的 5 倍（aOR=5.02，CI 2.47-10.20，P<0.001），超重的可能性是体重正常母亲的孩子的 4 倍以上（aOR=4.33，CI 2.65-7.09，P<0.001）。暴露于 HIV 与未暴露于 HIV 的儿童在任何结果上的差异都很小，且无统计学意义。该研究的主要局限性是母乳喂养的持续时间基于母亲的回忆。
据我们所知，这是第一项在 HIV 流行率较高的非洲环境中检查和量化母乳喂养与儿童肥胖之间关联的研究。我们观察到，母乳喂养与暴露于 HIV 和未暴露于 HIV 的儿童的肥胖均呈独立相关，这表明在整个生命过程中促进最佳营养，从持续母乳喂养开始，可能是应对日益严重的肥胖症流行的关键。在普遍有效的抗逆转录病毒治疗为所有 HIV 感染妇女终生提供的时代，这些数据进一步支持了所有妇女母乳喂养的建议。
