Association Between Self-Reported Faster Walking Pace and Subclinical Hypothyroidism in Relation to the Status of Atherosclerosis

Background/Objectives: This study examined the association between self-reported walking pace and subclinical hypothyroidism (SCH) in relation to atherosclerotic status, as both walking pace and SCH have been linked to an increased risk of all-cause mortality and cardiovascular disease. The vascular network underlying atherosclerotic processes may help explain this relationship. Methods: This was a cross-sectional study involving 1719 Japanese with normal thyroid function (free triiodothyronine [T3] and free thyroxine [T4] levels within the normal range). Since all individuals who participated in this study had free T3 and free T4 levels within the normal range, those with elevated TSH levels (>4.01 μIU/mL) were classified as having SCH. Self-reported faster walking pace was identified based on the participants’ responses to whether they perceived themselves as walking faster than their peers of the same age and sex. Logistic regression models were used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for SCH. Results: Of the study participants, 166 had atherosclerosis and 98 had SCH. Among individuals without atherosclerosis, a self-reported faster walking pace was significantly inversely associated with SCH but not among those with atherosclerosis. The sex and age-adjusted ORs (95% CIs) of SCH for self-reported faster walking pace were 0.58 (0.37, 0.91) for those without atherosclerosis and 2.35 (0.75, 7.36) for those with atherosclerosis. Atherosclerosis showed a significant interaction with the association between SCH and self-reported faster walking pace, with sex- and age-adjusted p-values of 0.027. These associations persisted, even after adjusting for potential confounding factors. Conclusions: Self-reported faster walking pace is inversely associated with SCH in individuals without atherosclerosis but not in those with atherosclerosis. Atherosclerosis status may influence the association between SCH and self-reported faster walking pace.