Increased Spot Urine Albumin-to-Creatinine Ratio and Stroke Incidence: A Systematic Review and Meta-Analysis

Objective: This study aimed to clarify the association between an increased spot urine albumin-to-creatinine ratio (UACR) and the risk of stroke. Methods: We performed a systematic review and meta-analysis of cohort studies, case-control studies, and ancillary data randomized controlled trials (RCTs), which were treated as cohorts in this study, and estimated the association between albuminuria, as measured with the UACR, and the risk of stroke. We performed a comprehensive search of PubMed, Embase, and the Cochrane Library and conducted a systematic review and cumulative meta-analysis of cohort studies with a cross-sectional with prospective design in which stroke incidence was reported and the baseline UACR was measured. Ancillary data from RCTs were also included as part of the cohort study. We studied the characteristics of the participants, quality scores and risk ratios (RR, with confidence intervals, CI) of stroke associated with normal and high UACRs, and we synthesized the data via a meta-analysis. Results: Twelve eligible studies including a total of 32,888 participants and 3,944 cases of stroke were identified. A high UACR (>30 mg/mmol) increased the risk of stroke by 1.67 times (RR: 1.67, 95% CI: 1.49-1.86, P<0.001 I-2 = 26%). The results were not different between Asian and non-Asian patients (RR: 1.64, 95% CI: 1.41-1.91, P<0.001, I-2 = 23% compared with RR: 1.67, 95% CI: 1.50-1.85, P<0. 00, I-2 = 39%) or between subgroups classified by old age (RR: 1.61, 95% CI: 1.39-1.88, P<0.001, I-2 = 34% compared with RR: 1.68, 95% CI: 1.52-1.87, P<0.001, I-2 = 13%). A sensitivity analysis did not significantly change the results. Conclusion: The incidence of stroke increased significantly in the high UACR group compared with the normal UACR group. The UACR could be a clinical addition for the early indication of high-risk stroke patients.