Microalbuminuria is independently associated with deep or infratentorial brain microbleeds in hypertensive adults.

Background: Brain microbleeds (BMBs) detected on gradient echo T2*-weighted magnetic resonance imaging (GE-MRI) may be pathophysiologically linked to ischemic cerebral small-vessel disease (SVD) and increased risk of future hemorrhagic stroke. Chronic kidney disease (CKD) has been associated with the presence of BMBs in stroke patients. However, the relationship between CKD markers and BMBs in stroke-free populations is unknown.

Methods: Two hundred and eighty-five hypertensive subjects (mean age 68.6 years) without neurological symptoms were enrolled from a hospital-based outpatient clinic and all participants underwent GE-MRI. We calculated urinary albumin/creatinine ratio (UACR) from morning spot urine and the estimated glomerular filtration rate (eGFR) in serum samples. Multivariate logistic regression analysis was used to evaluate the association between these kidney biomarkers and the presence and location of BMBs, controlling for age, sex, use of antihypertensive or antithrombotic drugs, and MRI findings.

Results: BMBs were observed in 48 (16.8%) patients. Median UACRs were significantly higher in patients with deep or infratentorial BMBs than in patients with pure lobar BMBs (54 vs. 17 mg/g creatinine, P = 0.04). No significant differences were found between eGFR levels and the location of BMBs. Microalbuminuria (UACR >30- ≤300 mg/g creatinine), but not low eGFR level was significantly associated with higher prevalence of deep or infratentorial BMBs (odds ratio (OR): 3.16, 95% confidence interval (CI): 1.34-7.44, P = 0.009) even after adjustment for potential confounding factors.

Conclusions: Microalbuminuria is closely associated with the prevalence of deep or infratentorial BMBs in hypertensive patients. Our findings provide new insights into the association between risk factors and the distribution of BMBs.