Vascular disease and apathy symptoms in the very old: A cross-sectional and longitudinal meta-analysis of individual participant data.

Objectives: Previous findings suggest a vascular foundation underlying apathy, but transdiagnostic and prospective evidence on vascular apathy is scarce. This study examines the association between vascular disease and the presence and development of apathy symptoms in the very old.

Methods: Four cohorts of the Towards Understanding Longitudinal International older People Studies (TULIPS)-consortium were included in a two-staged, individual participant data meta-analysis using generalized linear mixed models. Vascular disease was defined as a history of any clinical atherosclerotic pathology (angina pectoris, myocardial infarction, intermittent claudication, transient ischemic attack, stroke or related surgeries) and was related to apathy symptoms as repeatedly measured by the Geriatric Depression Scale (GDS-3A ≥2) over a maximum of 5 years.

Results: Of all 1868 participants (median age 85 years old), 53.9% had vascular disease and 44.3% experienced apathy symptoms. Participants with vascular disease had a 76% higher risk of apathy symptoms at baseline (odds ratio (OR) 1.76, 95% confidence interval (CI) 1.32-2.35), irrespective of depressive symptoms and only partially explained by stroke. Conversely, there was no association of vascular disease with the occurrence of apathy symptoms longitudinally, both in those with apathy at baseline (OR 1.00, 95% CI 0.84-1.20) and without (OR 0.96, 95% CI 0.84-1.09).

Conclusions: Vascular disease in the very old is associated with apathy symptoms cross-sectionally, but not proven longitudinally, independent of depressive symptoms. These findings query a vascular cause underlying apathy symptoms. However, the consistency of our cross-sectional findings in direction and magnitude across the TULIPS-consortium do emphasize international relevance of the interplay of vascular factors and apathy in advanced age, which meaning needs further unravelling.