Hyacinth HI, et al. - Researchers examined the association between sickle cell trait (SCT) and a higher risk of incident ischemic stroke among African Americans via meta-analysis. No link was verified, so researchers recommended a more comprehensive clinical evaluation of stroke patients with SCT instead of assuming SCT was the etiologic factor for stroke.

Methods

• Four large, prospective, population-based studies with African American cohorts were analyzed: Jackson Heart Study (September 1, 2005, through December 31, 2012), Multi-Ethnic Study of Atherosclerosis (July 1, 2002, through December 31, 2012), Reasons for Geographic and Racial Differences in Stroke (January 1, 2003, through December 31, 2014), and Women’s Health Initiative (October 1, 1998, through December 31, 2012).
• This study estimated the hazard ratio for incident ischemic stroke associated with SCT using a Cox proportional hazards regression model adjusted for major stroke risk factors.
• Data analysis was carried out from July 10, 2016, to February 2, 2017.
• As a part of the exposures, participants’ SCT status was determined by polymerase chain reaction assay genotyping or a combination of whole-exome sequencing and imputation.
• Incident ischemic stroke served as the main outcome.

Results

• A total of 19,464 African American individuals (1,520 with SCT, 17,944 without SCT, and 620 with ischemic stroke) from four studies, with a mean (SD) age of 60.0 (13.0) years (5,257 [27.0%] men and 14,207 [73.0%] women) were enrolled.
• There were no variations in the distribution of risk factors for ischemic stroke between participants with and those without SCT at study visit 1 in each cohort.
• It was determined that the crude incidence of ischemic stroke was 2.9 per 1,000 person-years (95% CI, 2.2-4.0 per 1,000 person-years) among those with SCT and 3.2 per 1,000 person-years (95% CI, 2.7-3.8 per 1,000 person-years) among those without SCT.
• Following adjustment for stroke risk factors, the hazard ratio of incident ischemic stroke appeared to be independently related to SCT in the meta-analysis of all four cohorts, which was 0.80 (95% CI, 0.47-1.35; P=.82).
• These results were similar to those of individual cohorts.