Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, USA.
Department of Clinical Epidemiology, Aarhus University, Aarhus, Denmark.
Influenza Other Respir Viruses. 2018 May;12(3):314-318. doi: 10.1111/irv.12542. Epub 2018 Mar 1.
Substantial but inconclusive evidence suggests in utero exposure to influenza infection may be linked with Alzheimer's disease.
We examined whether individuals exposed in utero to the 1918 influenza pandemic are at increased risk of dementia.
PATIENTS/METHODS: In this cohort study, surveillance data were used to identify months when influenza activity was at its peak during the pandemic. Using birth dates, exposed and unexposed individuals were identified based on whether they were in utero during ≥1 of the peak months. The outcome, any type of dementia, was identified in population-based medical registries. Time and age at risk were restricted so exposed and unexposed had equal time at risk; diagnoses for dementia were assessed between ages 62 and 92, with a maximum of 30 years at risk. Poisson regression was used to estimate sex-adjusted incidence rate ratios (IRRs).
We identified 106 479 exposed and 177 918 unexposed persons. Using the cumulative risk function, there were similar proportions of exposed and unexposed with a dementia diagnosis at 11.9% and 11.7%, respectively. Across all ages, the IRR for the association between in utero influenza exposure and any dementia was 1.01 (95% CI 0.99-1.04); for Alzheimer's disease, it was 0.97 (0.93-1.01). When stratified by age and sex, and when dementia type was examined, estimates of association were also null or close to null.
Our study suggests there is likely not an association between in utero exposure to the 1918 influenza pandemic and dementia among those 62 and older.
大量但尚无定论的证据表明，子宫内暴露于流感感染可能与阿尔茨海默病有关。
我们研究了在子宫内暴露于 1918 年流感大流行的个体是否患痴呆症的风险增加。
患者/方法：在这项队列研究中，使用监测数据来确定大流行期间流感活动达到高峰的月份。根据出生日期，根据他们是否在≥1个高峰月份在子宫内，确定暴露和未暴露个体。在基于人群的医疗登记处确定结局，任何类型的痴呆症。风险时间和年龄受到限制，以使暴露和未暴露的个体具有相等的风险时间；在 62 岁至 92 岁之间评估痴呆症的诊断，最大风险为 30 年。使用泊松回归估计性别调整后的发病率比（IRR）。
我们确定了 106479 名暴露者和 177918 名未暴露者。使用累积风险函数，暴露组和未暴露组分别有 11.9%和 11.7%的人被诊断为痴呆症。在所有年龄组中，子宫内流感暴露与任何痴呆症之间的关联的 IRR 为 1.01（95%CI 0.99-1.04）；对于阿尔茨海默病，为 0.97（0.93-1.01）。按年龄和性别分层，以及检查痴呆症类型时，关联的估计值也为零或接近零。
我们的研究表明，在 62 岁及以上人群中，子宫内暴露于 1918 年流感大流行与痴呆症之间可能没有关联。
