Loneliness and subjective cognitive impairment in preclinical Alzheimer’s disease and healthy aging

Abstract

AbstractBackgroundLoneliness is associated with increased dementia risk, and greater amyloid‐β (Aβ) and tau accumulation in cognitively normal older adults. However, the potential for loneliness to influence cognitive dysfunction during the preclinical disease stage has not yet been examined. Subjective cognitive complaints are an early indicator of cognitive dysfunction in Alzheimer’s disease, and may provide a sensitive endpoint to evaluate the influence of loneliness during the preclinical disease stage. This study evaluated the relationships between loneliness, subjective cognition, and Aβ status in cognitively unimpaired older adults.MethodParticipants were 112 older adults aged 60–81 years (68% female, 89% White) recruited from the Butler Hospital Alzheimer’s Prevention Registry (BAPR). A cut off score of ≥34 on a modified Telephone Interview for Cognitive Status (TICSm) was used to establish unimpaired cognition. All participants completed the 3‐item version of the UCLA Loneliness Scale and the Cognitive Function Index (CFI) to assess loneliness and subjective cognition respectively. At the time of this analysis, a subsample (n = 63) had also undergone PET neuroimaging for classification of Aß status, of which 40% were classified as Aß+.ResultOf the total sample, 28% reported mild‐moderate levels of loneliness, and another 8% reported severe loneliness. Subjective cognitive function was significantly associated with loneliness group, H(2) = 6.66, p = .036, with post hoc analyses indicating a significant trend for subjective cognitive complaints to increase with loneliness severity. Among the PET subsample, there was no significant difference observed between Aß groups in level of loneliness (p = .754) or subjective cognition (p = .852). However, there was a significant association between Aß status and loneliness group (p = .023), with Aß+ individuals being more likely to a be severely lonely (12%, n = 3) relative to the Aß‐ group (0%, n = 0).ConclusionThe results of this study highlight the potential for loneliness to be involved in the preclinical stages of AD by demonstrating associations with both subjective cognitive function and Aß status. Prospective investigations are needed to further disentangle whether loneliness may be an indicator of, or a risk factor for, emerging disease.