Cardiovascular-kidney-metabolic syndrome and incidence of dementia among older adults

BACKGROUND: Cardiovascular-Kidney-Metabolic Syndrome (CKM) has profound impacts on cardiovascular events and mortality, yet its association with dementia risk remains poorly understood. OBJECTIVES: To investigate associations between CKM and dementia risk. DESIGN: The prospective cohort study is within the Health, Aging, and Body Composition study, which enrolled participants from 1997 to 1998, with a 15-year follow-up for incident dementia. SETTING: The population-based study took place in two US communities in Memphis, Tennessee, and Pittsburgh, Pennsylvania. PARTICIPANTS: Of the 3,075 participants aged 70 to 79 years initially enrolled, 14 were excluded for lacking baseline cognitive assessment, 308 for baseline cognitive impairment, 4 for missing follow-up, and 108 for missing CKM data, resulting in 2,641 in the analysis. MEASUREMENTS: CKM staging, as defined recently by the American Heart Association framework, was based on constructs comprising dysfunctional adiposity, metabolic risk factors, chronic kidney disease (CKD), and cardiovascular disease (CVD). Dementia was identified using hospital records, prescriptions for dementia medication, and a test of global cognition. Adjusted Cox and Fine-Gray proportional hazards models were used to estimate dementia risk and account for competing risk of death. RESULTS: The 2,641 participants had a mean (SD) age of 74 (2.8) years at baseline; 53 % were female, 36 % were of Black race, and had a range of baseline CKM: 3 % Stage 0 (no CKM), 4 % Stage 1 (excess/dysfunctional adiposity), 26 % Stage 2 (metabolic risk factors), 24 % Stage 3 (subclinical CVD and CKD), and 43 % Stage 4 (clinical CVD and CKD). Compared to participants with CKM Stages 0-2, those with CKM Stages 3-4 had a 50 % increase in dementia risk (hazard ratio 1.50, 95 % CI 1.20 to 1.86) in the fully adjusted model. The association remained significant after additional adjustment for metabolic risk factors, CVD, and CKD, both separately and together. Accounting for competing risk of death yielded similar results. CONCLUSIONS: Among community-dwelling older adults, advanced CKM is associated with an increased risk of dementia. Older adults with CKM may need to be followed closely for adverse cognitive outcomes, and modifiable risk factors should be managed proactively.