HETEROGENEITY OF NEUROPSYCHOLOGICAL PROFILES IN OLDER ADULTS WITH VASCULAR DISEASE: A LATENT CLASS ANALYSIS APPROACH

Abstract

Despite the common co-occurrence of the two main pathological processes in aging, vascular disease and Alzheimer's disease (AD), they are often examined in isolation. Increasing evidence of a mutually enhancing relation between these processes is supported by common risk factors including hypertension and diabetes. Therefore, both processes must be considered in characterizing the cognitive performance of older adults, particularly given high rates of vascular disease. The heterogeneity of cognitive deficits has not been systematically examined in older adults with vascular disease. In a large sample of older adults (N = 359, Mage= 74.7) with increased vascular risk associated with cardiac disease, classes of participants were identified using latent class analysis (LCA) based on their performance across neuropsychological measures of executive functions and episodic memory. The cognitively-defined classes were compared on neuroimaging variables including white matter lesion (WML) and hippocampal volumes in 203 participants and on vascular risk quantified by Framingham score in 187 participants. LCA on the cognitive variables supported a three-class model, with Class 3 (intact; n = 178) showing relatively intact cognitive test scores compared to the other classes and Classes 1 (mildly impaired; n = 136) and 2 (dysexecutive; n = 42) demonstrating uniformly low scores, with Class 2 showing the lowest and most impaired scores on two executive measures (Trails B and Mental Control). Follow-up analyses found that differences between classes on WML and hippocampal volumes did not reach statistical significance, although a trend was observed in WML volumes (p = .12) with greater levels of this pathology in Class 2 (dysexecutive). Significant differences between the classes on vascular risk were revealed, with Class 2 showing significantly higher Framingham scores (p =.02). These findings suggest meaningful heterogeneity in the cognitive presentation of older adults with increased vascular risk, with deficits in executive functions associated with potentially modifiable vascular risk factors/cerebrovascular disease.