Data were from the waves 10-14 (2010-2018) of the Health and Retirement Study in the USA and the waves 5-9 (2010-2018) of the English Longitudinal Study of Ageing in England. We included 17,750 US and 8,491 English participants aged 50 years and over. The gender-specific HRB clustering was identified at the baseline wave in 2010, including the multi-HRB (multiple positive behaviours), inactive and ex-smoking clusters in both US and English women, the multi-HRB, inactive and smoking clusters in US men, and only the multi-HRB and inactive clusters in English men. Episodic memory was measured by a sum score of immediate and delayed word recall tests across waves. For within country associations, a quadratic growth curve model (age-cohort model, allowing for random intercepts and slopes) was applied to assess the gender-stratified associations between HRB clustering and episodic memory trajectories, considering a range of confounding factors. For between country comparisons, we combined country-specific data into one pooled dataset and generated a country variable (0 = USA and 1 = England), which allowed us to quantify between-country inequalities in the trajectories of episodic memory over age across the HRB clusters. This hypothesis was formally tested by examining a quadratic growth curve model with the inclusion of a three-way interaction term (age × HRB clustering × country).
We found that within countries, US and English participants within the multi-HRB cluster had higher scores of episodic memory than their counterparts within the inactive and (ex-)smoking clusters. Between countries, among both men and women within each HRB cluster, faster declines in episodic memory were observed in England than in the USA (e.g., b England versus the USA for men: multi-HRB cluster = -0.05, 95%CI: -0.06, -0.03, b England versus the USA for women: ex-smoking cluster = -0.06, 95%CI: -0.07, -0.04). Additionally, the range of mean memory scores was larger in England than in the USA when comparing means between two cluster groups, including the range of means between inactive and multi-HRB cluster for men (b England versus the USA = -0.56, 95%CI: -0.85, -0.27), and between ex-smoking and multi-HRB cluster for women (b England versus the USA = -1.73, 95%CI: -1.97, -1.49).
HRB clustering was associated with trajectories of episodic memory in both the USA and England. The effect of HRB clustering on episodic memory seemed larger in England than in the USA. Our study highlighted the importance of being aware of the interconnections between health behaviours for a better understanding of how these behaviours affect cognitive health. Governments, particularly in England, could pay more attention to the adverse effects of health behaviours on cognitive health in the ageing population.
数据来自美国健康与退休研究的第10-14波(2010-2018)和英国老龄化纵向研究的第5-9波(2010-2018)。我们包括17,750名美国和8,491名50岁及以上的英国参与者。在2010年的基线波中确定了特定性别的HRB聚类,包括多HRB(多种积极行为),美国和英国女性的不活跃和戒烟集群,多HRB,美国男性不活跃和吸烟,只有英国男性的多HRB和不活跃的集群。情景记忆是通过跨波的即时和延迟单词回忆测试的总和来衡量的。对于在国家协会内部,二次生长曲线模型(年龄队列模型,允许随机截距和斜率)用于评估HRB聚类和情景记忆轨迹之间的性别分层关联,考虑到一系列混杂因素。对于国家之间的比较,我们将特定国家的数据合并到一个汇集的数据集中,并生成一个国家变量(0=美国,1=英国),这使我们能够量化跨HRB集群的情景记忆随年龄增长的轨迹中的国家间不平等。通过检查包含三向相互作用项(年龄×HRB聚类×国家)的二次增长曲线模型,对该假设进行了正式检验。
我们发现在国家内部,多HRB集群中的美国和英国参与者的情景记忆得分高于非活动和(前)吸烟集群中的参与者。国家之间,在每个HRB集群中的男性和女性中,在英格兰,情景记忆的下降速度比在美国快(例如,b英格兰与美国的男性:多HRB组=-0.05,95CI:-0.06,-0.03,b英格兰与美国的女性:前吸烟组=-0.06,95CI:-0.07,-0.04)。此外,当比较两个聚类组之间的均值时,英格兰的平均记忆得分范围大于美国,包括男性不活跃和多HRB集群之间的均值范围(b英格兰对美国=-0.56,95CI:-0.85,-0.27),女性吸烟和多HRB集群之间(b英格兰与美国=-1.73,95CI:-1.97,-1.49)。
在美国和英国,HRB聚类与情节记忆的轨迹有关。在英国,HRB聚类对情景记忆的影响似乎比美国更大。我们的研究强调了意识到健康行为之间相互联系的重要性,以便更好地了解这些行为如何影响认知健康。各国政府,尤其是在英国,可以更加关注健康行为对老年人认知健康的不利影响。