Primary etiology and associated medical conditions in Mild Cognitive Impairment Subtypes in the NACC Database

Abstract

AbstractBackgroundMild cognitive impairment (MCI) reflects cognitive deficits without significant functional decline in activities of daily living (1). MCI subtypes correspond to phenotypic cognitive impairment patterns in memory, attention, language, executive, and visuospatial compared to age‐adjusted norms: Amnestic single domain (ASD) or multi‐domain (AMD), Nonamnestic single domain (NASD), or Nonamnestic multi‐domain (NAMD). Previous studies have suggested nonamnestic subtypes are more likely to represent non‐AD prodromes, but conclusions have been limited by small sample sizes (1).MethodUsing the National Alzheimer’s Coordinating Center (NACC) database (grant U24 AG072122), we selected all initial Uniform Data Set (UDS) assessments diagnosed as MCI with subtyping. The NACC data was collected from 37 participating Alzheimer’s disease Research Centers. Baseline clinical features, primary etiology and associated medical conditions were collected.Results9852 individuals with MCI on baseline UDS visits were analyzed: 45.6% were diagnosed with AD (Table 1). AD was the most common primary etiology in all subtypes, more frequent in amnestic than nonamnestic subtypes (AMD 54.1%; ASD 50.5%; NAMD 20.0%; NASD 18.8%). Overall, 6% were diagnosed with DLB and 3.1% with PD; NAMD and NASD were more frequent than AMD or ASD. The most frequently associated medical conditions were hypercholesterolemia, HTN, depression, anxiety, sleep apnea and diabetes (table 2). The highest percentage of depression and anxiety were in nonamnetsic subtypes. Recent stroke was most frequent in NAMD.ConclusionMCI is a heterogeneous disorder, and its classification by subtypes is essential in understanding prodromal stages and neurodegenerative neuropathology. Dementia risk modulation and prevention is linked to identification and treatment of associated medical conditions including frequent neuropsychiatric comorbidity (2).