Department of Clinical Sciences/Faculty of Medicine, Lund University, Malmö, Skåne County, Sweden.
RWI-Leibniz Institute for Economic Research, Essen, Germany.
J Gerontol B Psychol Sci Soc Sci. 2023 Dec 6;78(12):2131-2140. doi: 10.1093/geronb/gbad142.
Very early-life conditions are recognized as critical for healthy brain development. This study assesses early-life risk factors for developing dementia. In the absence of historical medical birth records, we leverage an alternative full population approach using demographic characteristics obtained from administrative data to derive proxy indicators for birth complications and unfavorable birth outcomes. We use proxy variables to investigate the impact of early-life risk factors on dementia risk.
We use administrative individual-level data for full cohorts born 1932-1950 in Sweden with multigenerational linkages. Records on hospitalization and mortality are used to identify dementia cases. We derive 3 birth risk factors based on demographic characteristics: advanced maternal age, narrow sibling spacing, and twin births, and apply survival analysis to evaluate long-term effects on dementia risk. We control for confounding using multiple indicators for socio-economic status (SES), including parental surnames, and by implementing a sibling design. As comparison exposure, we add low education from the 1970 Census.
The presence of at least 1 birth risk factor increases dementia risk (HR = 1.059; 95% CI: 1.034, 1.085). The occurrence of twin births poses a particularly heightened risk (HR = 1.166; 95% CI: 1.084, 1.255).
Improvements to the very early-life environment hold significant potential to mitigate dementia risk. A comparison to the influence of low education on dementia (the largest known modifiable risk factor) suggests that demographic birth characteristics are of relevant effect sizes. Our findings underscore the relevance of providing assistance for births experiencing complications and adverse health outcomes to reduce dementia cases.
生命早期的条件被认为对大脑健康发育至关重要。本研究评估了导致痴呆的生命早期危险因素。由于缺乏历史上的医疗出生记录，我们利用一种替代的全人群方法，使用从行政数据中获得的人口特征来推导出出生并发症和不良出生结局的代理指标。我们使用代理变量来研究生命早期危险因素对痴呆风险的影响。
我们使用瑞典全队列的行政个体水平数据，这些队列出生于 1932 年至 1950 年，具有多代关联。通过住院和死亡率记录来确定痴呆病例。我们根据人口特征得出了 3 个出生风险因素：母亲年龄较大、兄弟姐妹间隔较窄和双胞胎出生，并应用生存分析来评估对痴呆风险的长期影响。我们通过使用包括父母姓氏在内的多个社会经济地位（SES）指标和实施兄弟姐妹设计来控制混杂因素。作为比较暴露，我们从 1970 年人口普查中添加了低教育。
至少存在 1 个出生风险因素会增加痴呆风险（HR=1.059；95%CI：1.034，1.085）。双胞胎的出生尤其存在较高的风险（HR=1.166；95%CI：1.084，1.255）。
改善生命早期环境具有减轻痴呆风险的巨大潜力。与低教育对痴呆的影响（已知最大的可改变风险因素）进行比较表明，人口出生特征具有相关的效应大小。我们的研究结果强调了为经历并发症和不良健康结局的分娩提供援助以减少痴呆病例的重要性。
