Across 28,242 older adults from international aging cohorts followed for roughly 5 to 6.5 years, advanced cardiovascular-kidney-metabolic (CKM) syndrome (AHA stages 3-4) tracked with accelerated decline in attention, executive function and language, plus more depressive symptoms among cognitively unimpaired people. Six modifiable factors accounted for 24.8% of cognitive impairment risk across CKM stages: social isolation (7.0%), depressive symptoms (5.2%) and physical inactivity (5.2%) led. In UK Biobank imaging, advanced CKM was tied to 27 of 34 MRI biomarkers, most prominently white matter hyperintensities.
The white matter signal points toward small-vessel cerebrovascular injury as the likely bridge between heart, kidney and metabolic disease and a failing brain, consistent with prior work on hypertension and diabetes. The finding that APOE4 status did not modify the association suggests this risk pathway is largely independent of genetic susceptibility, which is encouraging because vascular and metabolic factors can be treated. The stronger effects in younger, male and less-educated participants merit follow-up. Caveats matter: the design is observational, the MRI analysis is cross-sectional, and population-attributable fractions assume causality that these data cannot prove. This is a preprint, not yet peer reviewed, so estimates may shift. Overall the work is confirmatory rather than paradigm-shifting, but it usefully frames practical priorities: control blood pressure, glucose and kidney risk early, stay physically active, and treat loneliness and depression as brain-health targets.