BACKGROUND As the population ages, cognitive decline and dementia have become major health concerns in the UK. Loneliness has been linked to cognitive decline, but the reverse causality of this association remains unclear. This study aims to examine whether there is a bidirectional relationship between loneliness and cognitive function in older English adults (age 50 years and over) over a 10-year follow-up. METHODS Data came from a nationally representative sample of 5885 participants in the English Longitudinal Study of Ageing (ELSA), free of stroke or dementia and followed every 2 years up to wave 7 (2014-15). At each wave, cognitive function was measured with word recall and verbal fluency tests, and loneliness was measured with the abridged version of the revised UCLA Loneliness Scale. Bivariate dual change score models were used to assess the multivariate associations between loneliness and cognitive function, used interchangeably as exposures and outcomes. RESULTS Greater loneliness at baseline was associated with poorer memory [β intercept = -0.03, standard error (SE) = 0.01, P  =  0.016] and verbal fluency (β intercept = -0.01, SE  =  001, P =  0.027) at baseline, and with a stronger linear rate of decline in both memory (β linear slope = -0.07, SE  =  001, P  ≤ 0.001) and verbal fluency (β linear slope = -0.09, SE  =  0.03, P =  0.003) over a 10-year follow-up period, although the performance on verbal fluency did not change substantially on average over this period. We also found that higher baseline memory, but not verbal fluency, predicted a slower change in loneliness (β linear slope = -0.01, SE  =  001, P =  0.004) and that a linear decline in memory was associated with an acceleration in loneliness (β quadratic slope = -0.02, SE  =  001, P  ≤ 0.001) during follow-up. CONCLUSIONS Higher loneliness is associated with poorer cognitive function at baseline and contributes to a worsening in memory and verbal fluency over a decade. These factors seem, however, to be partially intertwined, since baseline memory and its rate of decline also contribute to an increase in loneliness over time.

中文翻译：

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探索孤独与认知功能之间的双向关联超过10年：英语纵向研究衰老。

背景技术随着人口的老龄化，认知能力下降和痴呆症已成为英国的主要健康问题。孤独与认知能力下降有关，但这种关联的反向因果关系尚不清楚。这项研究的目的是研究在为期10年的随访中，年龄较大的英国成年人（50岁及以上）的孤独感与认知功能之间是否存在双向关系。方法数据来自全国性代表性样本，该样本来自5885名英国老年人纵向研究（ELSA），无中风或痴呆症，每两年随访一次，直至第7浪（2014-15）。在每一波中，通过单词回忆和口语流利度测试来测量认知功能，并使用修订后的UCLA孤独感量表的简化版来测量孤独感。双变量双变化评分模型用于评估孤独性与认知功能之间的多变量关联，可互换地用作暴露和结果。结果基线时的孤独感较高与基线时的记忆力较差[β截距= -0.03，标准误（SE）= 0.01，P = 0.016]和口头流利度（β截距= -0.01，SE = 001，P = 0.027）相关，并且在10倍内，记忆力（β线性斜率= -0.07，SE = 001，P≤0.001）和口头流利性（β线性斜率= -0.09，SE = 0.03，P = 0.003）的线性下降率均较强。一年的随访期间，尽管在此期间，语言流利性的平均表现没有实质性变化。我们还发现，较高的基线记忆力而非言语流畅度可预测孤独感的变化较慢（β线性斜率= -0.01，SE = 001，P = 0。004），并且记忆的线性下降与随访期间的孤独感加速有关（β二次方斜率= -0.02，SE = 001，P≤0.001）。结论较高的孤独感与基线时较差的认知功能有关，并在十年内导致记忆力和言语流畅性恶化。然而，这些因素似乎是部分交织在一起的，因为随着时间的推移，基线记忆及其下降速度也会导致孤独感的增加。