Peripheral capillary rarefaction is associated with cerebral small vessel disease burden: a population-based study

BackgroundPeripheral microvascular abnormalities may reflect systemic microvascular dysfunction relevant to cerebral small vessel disease (cSVD), yet their relationship to individual neuroimaging markers and overall cSVD burden remains unclear. We evaluated whether abnormalities in nailfold capillaroscopy (NFC) are associated with specific cSVD markers and with the total cSVD score in a population-based cohort. MethodsAtahualpa residents aged [≥]60 years underwent NFC and brain MRI. Capillary tortuosities, dilatations, density, and megacapillaries were quantified using automated software with expert validation. Neuroimaging markers included white matter hyperintensities (WMH), lacunes, deep cerebral microbleeds (CMB), and enlarged basal ganglia perivascular spaces (BG-PVS). Logistic regression models assessed associations between NFC abnormalities and cSVD markers. Poisson regression was used to model the total cSVD score. All models were adjusted for demographics, educational attainment, and cardiovascular risk factors. ResultsAmong 289 participants (mean age 71.3 {+/-} 7.5 years; 51% women), lower capillary density was independently associated with CMB (OR: 0.70; 95% C.I.: 0.51-0.96) and lacunes (OR: 0.67; 95% C.I.: 0.50-0.91), with a borderline association for WMH (p=0.062). Megacapillaries were independently associated with moderate-to-severe WMH (OR: 5.01; 95% C.I.: 1.42-17.68). Tortuosities and dilatations showed no significant associations. Higher capillary density was inversely associated with the total cSVD score ({beta}: -0.179; 95% C.I.: -0.283 to -0.075). ConclusionsReduced capillary density and megacapillaries track with the burden of cSVD. NFC may provide a noninvasive window into cerebral microvascular health and could inform risk stratification for cSVD progression and related outcomes.