Although several studies have shown small longitudinal associations between baseline loneliness and subsequent dementia risk, studies rarely test whether change in loneliness predicts dementia risk. Furthermore, as both increase with advancing age, genetic and environmental selection processes may confound the putative causal association between loneliness and dementia risk. We used a sample of 2,476 individual twins from three longitudinal twin studies of aging in the Swedish Twin Registry to test the hypothesis that greater positive change in loneliness predicts greater dementia risk. We then used a sample of 1,632 pairs of twins to evaluate the hypothesis that effects of change in loneliness on dementia risk would remain after adjusting for effects of genetic and environmental variance. Phenotypic model results suggest that mild levels of baseline loneliness predict greater dementia risk. Contrary to our hypothesis, change in loneliness did not correlate with dementia risk, regardless of whether genetic and environmental selection confounds were taken into account. Worsening loneliness with age may not confer greater dementia risk.

尽管一些研究表明基线孤独感与随后的痴呆风险之间存在较小的纵向关联，但研究很少测试孤独感的变化是否可以预测痴呆风险。此外，随着年龄的增长，两者都会增加，遗传和环境选择过程可能会混淆孤独感和痴呆风险之间假定的因果关系。我们使用瑞典双胞胎登记处三项关于衰老的纵向双胞胎研究中的 2,476 名双胞胎样本来检验这样的假设：孤独感的积极变化越大，患痴呆症的风险就越大。然后，我们使用 1,632 对双胞胎样本来评估这一假设，即在调整遗传和环境差异的影响后，孤独感的变化对痴呆风险的影响仍然存在。表型模型结果表明，轻度的基线孤独感预示着更高的痴呆风险。与我们的假设相反，无论是否考虑遗传和环境选择混杂因素，孤独感的变化与痴呆风险无关。随着年龄的增长，孤独感的加剧可能不会增加患痴呆症的风险。