Association between red cell distribution width level and risk of stroke: A systematic review and meta-analysis of prospective studies

BACKGROUND: Red cell distribution width level may have relations with the incidence and prognosis of cerebrovascular diseases. Recent researches have reported that red cell distribution width level was linked to the occurrence of stroke. However, the predicted effect of red cell distribution width in stroke is still disputed. We sought to assess the relationship between red cell distribution width and risk of stroke in this meta-analysis. METHODS: Relevant studies were picked out from the databases of Embase, PubMed, and Cochrane Library. Hazard ratio with 95% confidence interval was chosen to analyze each trial, which was extracted from results of the highest and lowest red cell distribution width group. Funnel plots, Begg and Egger test were used to assess publication bias in the meta-analysis. Stata(12.0) was utilized to perform statistic analysis in the process. RESULTS: A total of 6 studies with 5783 patients were included in this meta-analysis. The results showed that red cell distribution width level in patients with stroke was significantly higher than it in those without stroke (HR = 1.34, 95%CI:1.23–1.47, P < .001), in particular ischemic stroke(HR = 1.34,95% confidence interval:1.1–1.54, P < .001). There was no evidence of heterogeneity across the studies (P = .355, I(2) = 5.53%). CONCLUSIONS: The higher red cell distribution width level was associated with an increased risk of stroke, especially ischemic infarction.