Subclinical hypothyroidism is associated with elevated high-sensitive C-reactive protein among adult Taiwanese

Subjects with subclinical hypothyroidism (SCH) are at increased risk for cardiovascular disease (CVD). High-sensitivity C-reactive protein (hsCRP) is one of the inflammatory markers related to CVD. It is unclear whether inflammation is a mechanistic intermediary between SCH and CVD. We aimed to investigate the association between SCH and hsCRP in a Taiwanese population. A baseline cohort of 2,494 participants over the age of 19 was recruited in Taiwan from 2006 to 2008. SCH was defined as a serum thyroid-stimulating hormone (TSH) level of 5.61-19.9 mIU/L with normal thyroxine concentrations (a total T4 level of 4.9-12.0 μg/dL). Euthyroidism was defined as a serum TSH level of 0.34-5.60 mIU/L. HsCPR was grouped using quartiles. Multiple logistic and linear regression analyses were used to evaluate the relationship between hsCRP and SCH. After adjusting for gender and betel nut chewing, stepwise multiple logistic regression analyses revealed that hsCRP groups were significantly associated with SCH. Compared to the lowest hsCRP quartile, the adjusted odds ratio of having SCH for hsCRP quartile II, III, and IV were 1.38 (0.48-3.98), 1.48 (0.56-3.96), and 2.59 (1.01-6.67), respectively. The significant increase in odds ratios for SCH in progressive hsCRP quartiles reveals a dose-response effect (p < 0.05). Moreover, stepwise multiple linear regression analyses showed that hsCRP was significantly positively associated with serum TSH level after adjusting for potential confounders. Adult Taiwanese with SCH were associated with elevated hsCRP quartiles.