THYROID DYSFUNCTION AND BLOOD PRESSURE COMPONENTS: MULTIVARIATE STATISTICAL ASSOCIATIONS

Background: Although thyroid dysfunctions exert significant effects on blood pressure (BP), published literature available has revealed con-tradictory data. Objectives: To explore the inter-relationships between selected thyroid dysfunctional status (hyper and hypothyroid conditions) and estab-lished biomarkers [thyroid stimulating hormone (TSH) and thyroxine (T4)]; and BP components [specifically Systolic BP (SBP), Diastolic BP (DBP), and Mean Arterial Pressure (MAP), and uniquely SBP:DBP ratio]. Materials and Methods: We followed rigid criteria in order to select adults with hyperthyroidism (n=71) and hypothyroidism (n=300), together with healthy age-matched controls (n =300), and applied a series of statistical analysis strategies to the datasets acquired. Results: Univariate statistical analyses of the SBP:DBP ratio by ANOVA and ANCOVA revealed that its mean value was significantly greater in hyperthyroid patients than those of healthy control and hypothyroid subjects (p？0.0001). Body mass index (BMI) was significantly elevated in hypothyroid patients over those of healthy control and hyperthyroid subjects (p？0.0001); healthy controls had a significantly greater BMI value than that of hyperthyroid patients (p？0.0001). Multivariate (MV) analysis [redundancy analysis (RDA), canonical correlation analysis (CCorA), and principal component analysis (PCA)] demonstrated powerful relationships between all blood pressure components and thyroid disease classifications, together with their biomarker indices and further patient-related parameters. Conclusions: Since thyroid dysfunctional status is associated with elevated BP, and increasing BP is positively-correlated with elevated se-rum thyroid biomarkers, hyper and hypothyroid disorders should be recognized and treated early in order to avoid critical hazards presented by high BP