Galectin‐3 and risk of ischaemic stroke: Reasons for Geographic and Racial Differences in Stroke cohort

Background and purpose Galectin‐3 is a biomarker of atherosclerotic and cardiovascular disease, and may be a useful marker for ischaemic stroke risk. Methods The Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort enrolled and examined 30 239 US participants between 2003 and 2007 (41% black, 59% white and 55% in the southeastern stroke belt). Baseline galectin‐3 was measured in 526 subjects with incident ischaemic stroke over 5.4 years and in a cohort random sample (CRS) of 947 participants. Cox proportional hazards models were used to calculate hazard ratios (HRs) of ischaemic stroke by quartiles of galectin‐3. Results In the CRS, galectin‐3 was significantly higher with older age, black race, female sex, body mass index, hypertension, diabetes mellitus and kidney disease, and also in those who developed incident stroke. Participants with galectin‐3 levels in the fourth versus first quartile had a 2.3‐fold increased stroke risk [95% confidence interval (CI) 1.6, 3.4] in an unadjusted model. An interaction with age was found (P = 0.06), and therefore age‐stratified analyses were performed. Amongst those younger than age 64, baseline galectin‐3 in the second–fourth quartiles was associated with increased stroke risk (HR 3.0, 95% CI 1.6, 5.5) compared to the first quartile in an age‐, race‐ and sex‐adjusted model. The HR was 2.0 (95% CI 1.0, 4.0) with multivariable adjustment. There was no association amongst older participants. Conclusions Galectin‐3 was associated with incident ischaemic stroke in younger but not older individuals. Confirmation of this finding, and elucidation of its implications for stroke pathophysiology and prevention, is needed.