Whether sex/gender differences in rates of biological aging mediate sex/gender differences in cognition in older adults has not been fully examined. The aim of the current study was to investigate this association. Data from up to 1,928 participants (mean age = 75, SD = 7.04, female = 57%) who took part in the 2016 Harmonized Cognitive Assessment Protocol and Venous Blood Study; sub-studies of the Health and Retirement Study were included in the current study. The residuals from four age-adjusted epigenetic clocks (Horvath, Hannum, PhenoAge, and GrimAge) were used to measure biological age acceleration. Sex/gender differences in cognition were tested using a series of ANCOVAs. Mediation analyses tested whether the measures of age acceleration accounted for these sex/gender differences, controlling for age, education, smoking status, and white blood cell count. Women outperformed men on measures of verbal learning, verbal memory, visual scanning, and processing speed. No other significant sex/gender differences were identified. Results from mediation analyses revealed that women's slower rates of GrimAge fully accounted for their faster processing speeds and partially accounted for their better performances on verbal learning, verbal memory, and visual scanning measures. None of the other measures of age acceleration were significant mediators. Accounting for sex/gender differences in biological aging may differentiate between cognitive sex/gender differences that are driven by universal (i.e., age-related) versus sex-specific mechanisms. More broadly, these findings support the growing evidence that the GrimAge clock outperforms other clocks in predicting cognitive outcomes.

中文翻译：

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DNA 甲基化“GrimAge”加速介导言语记忆和处理速度中的性别差异：健康与退休研究的结果

生物衰老率的性别/性别差异是否介导老年人认知的性别/性别差异尚未得到充分研究。当前研究的目的是调查这种关联。来自参加 2016 年协调认知评估方案和静脉血研究的多达 1,928 名参与者（平均年龄 = 75，SD = 7.04，女性 = 57%）的数据；本研究纳入了健康与退休研究的子研究。四个年龄调整后的表观遗传时钟（Horvath、Hannum、PhenoAge 和 GrimAge）的残差用于测量生物年龄加速。使用一系列ANCOVA 测试了认知中的性别差异。中介分析测试了年龄加速的衡量标准是否解释了这些性别差异，并控制了年龄、教育程度、吸烟状况、和白细胞计数。在言语学习、言语记忆、视觉扫描和处理速度方面，女性的表现优于男性。没有发现其他显着的性别差异。中介分析的结果显示，女性的 GrimAge 速度较慢，完全是因为她们的处理速度更快，部分是因为她们在言语学习、言语记忆和视觉扫描测量方面表现更好。其他年龄加速指标都不是显着的中介因素。考虑到生物衰老中的性别差异，可以区分由普遍（即与年龄相关）机制驱动的认知性别差异与特定性别机制驱动的认知性别差异。更广泛地，