Supplementary Material for: Microalbuminuria and the Combination of MRI Markers of Cerebral Small Vessel Disease

Background: Kidney function has been related to the presence of individual markers of cerebral small vessel disease (CSVD), as lacunes, white matter hyperintensities (WMH) or microbleeds. We aimed at studying the relationship of kidney dysfunction with the combination of several markers of CSVD. Methods: Subjects are those included in the ISSYS cohort (Investigating Silent Strokes in hypertensives: a magnetic resonance imaging study). A scale ranging from 0 to 4 points was applied based on the presence (one point each) of lacunes, deep microbleeds, moderate to extensive basal ganglia enlarged perivascular spaces (EPVS), and periventricular or deep WMH. We determined the creatinine-based glomerular filtration rate and the urinary albumin-to-creatinine ratio (UACR) as markers of kidney function and studied their association with the scale of CSVD in univariate and ordinal logistic regression analyses. Results: Among the 975 patients included, 28.2% presented one or more CSVD markers, being the most prevalent marker (either alone or in combination) basal ganglia EPVS. The UACR was elevated at increasing the scores of the CSVD scale and remained as independent predictor of the combination of markers (common OR per natural log unit increase in UACR: 1.23, 1.07-1.41) after controlling per age, gender, cardiovascular risk, antihypertensive treatment and hypertension duration. In contrast, no associations were found between the CSVD scores and the creatinine-based estimated glomerular filtration rate. Conclusions: A significant proportion of stroke-free hypertensives present at least one imaging marker of CSVD. UACR but not creatinine-based glomerular filtration rate is associated with the combination of markers of CSVD.