Early-life environmental factors have been suggested in the pathophysiology of dementia. Season of birth has previously been used as a proxy for these external exposures. We investigated the link between season of birth and the risk of dementia and further explored underlying pathways by studying structural brain changes on MRI. From the Dutch, population-based Rotterdam Study, 12,964 participants born between 1887 and 1960 were followed between 1990 and 2018 for dementia. Cox regression was conducted to assess the association between season of birth and dementia. In addition, we distinguished between mild and cold winters. The association of season of birth with structural brain markers on MRI was examined in 5237 participants. The risk of dementia in participants born in winter and fall was higher than of those born in summer (hazard ratio (HR) 1.15 [95% confidence interval (CI) 1.01–1.31] for winter and HR 1.17 [95% CI 1.01–1.33] for fall), especially for Alzheimer’s disease (HR 1.23 [1.06–1.43] for winter and HR 1.15 [95% CI 0.99–1.35] for fall). The risk was particularly increased for participants born in a cold winter. Except for slightly lower hippocampus in fall born participants (β − 0.03; 95% CI − 0.06 to 0.00), we did not find associations with brain imaging markers. In conclusion, winter and fall births were associated with a higher incidence of dementia, especially of AD. We did not find evidence for structural brain changes as an underlying mechanism.

在痴呆症的病理生理学中已经提出了生命早期的环境因素。出生季节以前曾被用作这些外部暴露的代名词。我们研究了出生季节与痴呆症风险之间的联系，并通过研究MRI上的脑结构变化进一步探索了潜在的途径。来自荷兰的基于鹿特丹的人口研究显示，在1887年至1960年之间出生的12,964名参与者在1990年至2018年之间患有痴呆症。进行Cox回归以评估出生季节和痴呆之间的关联。此外，我们区分了冬季的寒冷和寒冷。在5237名参与者中检查了出生季节与MRI上的结构性脑标志物的关联。冬季和秋季出生的参与者患痴呆症的风险高于夏季（冬季的风险比（HR）1.15 [95％置信区间（CI）1.01–1.31]和HR 1.17 [95％CI 1.01–1.33]） ），尤其是针对阿尔茨海默氏病（冬季为HR 1.23 [1.06-1.43]，秋季为HR 1.15 [95％CI 0.99-1.35]）。对于在寒冷的冬季出生的参与者而言，这种风险尤其增加。除了秋季出生的参与者的海马体略低（β-0.03； 95％CI-0.06至0.00）外，我们没有发现与脑成像标志物的关联。总之，冬季和秋季出生与痴呆症的发生率较高，特别是与AD有关。我们没有发现结构性脑变化作为潜在机制的证据。特别是针对阿尔茨海默氏病（冬季为HR 1.23 [1.06-1.43]，秋季为HR 1.15 [95％CI 0.99-1.35]）。对于在寒冷的冬季出生的参与者而言，这种风险尤其增加。除了秋季出生的参与者的海马体略低（β-0.03； 95％CI-0.06至0.00）外，我们没有发现与脑成像标志物的关联。总之，冬季和秋季出生与痴呆症的发生率较高，特别是与AD有关。我们没有发现结构性脑变化作为潜在机制的证据。特别是针对阿尔茨海默氏病（冬季为HR 1.23 [1.06-1.43]，秋季为HR 1.15 [95％CI 0.99-1.35]）。对于在寒冷的冬季出生的参与者而言，这种风险尤其增加。除了秋季出生的参与者的海马体略低（β-0.03； 95％CI-0.06至0.00）外，我们没有发现与脑成像标志物的关联。总之，冬季和秋季出生与痴呆症的发生率较高，特别是与AD有关。我们没有发现结构性脑变化作为潜在机制的证据。我们没有发现与脑成像标志物的关联。总之，冬季和秋季出生与痴呆症的发生率较高，特别是与AD有关。我们没有发现结构性脑变化作为潜在机制的证据。我们没有发现与脑成像标志物的关联。总之，冬季和秋季出生与痴呆症的发生率较高，特别是与AD有关。我们没有发现结构性脑变化作为潜在机制的证据。