Background and purpose: White matter lesion (WML) is an indicator of small vessel disease, however, the underlying pathological mechanisms has not been fully understood. In recent years, experimental and epidemiological studies have suggested that chronic kidney disease (CKD) is associated with endothelial dysfunction; thereby, a CKD state may initiate small vessel damage. Our aim was to investigate the association of estimated glomerular filtration rate (eGFR), urinary albumin/creatinine ratio (UACR), and WML in first-ever stroke patients.
Methods: We retrospectively enrolled 284 consecutive patients (177 male; median age 72 years) admitted to our stroke center between May 2010 and January 2012. eGFR and UACR measurements were performed on admission. WML were assessed using the Fazekas classification. Severe WML was defined as Fazekas gradings of 2 or higher. The impact of the eGFR and UACR on WML was evaluated using multiple logistic regression analysis. Separate analyses were conducted according to severe WML and trichotomized eGFR level [60 mL/min ≤ eGFR (reference), 45 mL/min ≤ eGFR < 60 mL/min, and eGFR < 45 mL/min)] and UACR level [UACR < 30.0 mg/g creatinine (reference), 30.0 mg/g creatinine ≤ UACR < 300 mg/g creatinine, and 300 mg/g creatinine ≤ UACR].
Results: According to the Fazekas gradings, 91 patients (32.0%) had scale 0; 90 patients (31.7%), scale 1; 59 patients (20.8%), stage 2; and 44 patients (15.5%), scale 3. Age (P < 0.0001), sex (P = 0.0094), eGFR (P = 0.0173), UACR (P = 0.0001), hypertension (P = 0.0436), and brain natriuretic peptide (P = 0.0354) were significantly associated with severe WML. On multivariable logistic regression analysis, high UACR (≥ 39.6 mg/g creatinine), but not low eGFR (≤ 74 mL/min/1.73 m2), was independently associated with severe WML. In comparisons between trichotomized UACR level, severe WML were more frequent in UACR ≥ 300 mg/g creatinine group than in UACR < 30.0 mg/g creatinine group after multivariate adjustment (OR, 2.25; 95% CI, 1.04-5.00; P = 0.039). On the other hand, there was no significant association with trichotomized eGFR level and severe WML (OR, 1.51; 95% CI, 0.62-3.77; P = 0.3672).
Conclusions: Our data suggest that a high UACR, but not eGFR, is independently associated with severe WML.