Association between thyroid indices and ischemic stroke: Glycated albumin as a mediator

Abstract

Abstract Limited data are available on the association between the thyroid indices and ischemic stroke (IS) risk, and the mechanisms remain unclear. We aimed to investigate the associations of thyroid indices and the prevalence of IS and examine the mediating effects through glycated albumin (GA). A total of 332 patients with ischemic stroke were matched 1:1 to patients without ischemic stroke for age and gender. Serum thyroid indices (free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH) and GA were collected from biochemical test results. Multivariate conditional logistic regression analyses were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for thyroid indices and IS. Generalized linear models were used to analyze the associations between levels of thyroid indices and GA. Mediation analyses were further conducted to evaluate the potential mediating role of GA in the associations between thyroid indices and IS. Each SD increment of FT4 was associated with 26% higher odds (OR: 1.26; 95%CI: 1.05, 1.51) increment in ORs of IS. However, each SD increment of FT3 or FT3/FT4 ratio was associated with 20% lower odds (OR: 0.80; 95%CI: 0.67, 0.96) and 30% lower odds (OR 0.70; 95%CI: 0.58, 0.85) decrements in ORs of IS, respectively. Further mediation analyses indicated that GA mediated 18.16% and 11.35% of the associations between FT3 and FT3/FT4 ratio and IS, respectively. Higher serum FT4 or lower serum FT3 and FT3/FT4 ratio was associated with an increased risk of IS. The association of FT3 and FT3/FT4 ratio with IS was partially mediated by GA. Further large prospective studies are warranted to corroborate our findings.