Impact of thyroid function and polymorphisms in the type 2 deiodinase on blood pressure: the Rotterdam Study and the Rotterdam Scan Study

P>Introduction Thyroid function and genetic variation in the hypothalamus-pituitary-thyroid axis have been implicated in blood pressure regulation and susceptibility to hypertension. However studies conducted thus far were small with controversial results. Objective To examine whether serum thyroid parameters and polymorphisms in the type 2 deiodinase and the TSH receptor are associated with blood pressure and the presence of hypertension in two large cohorts of elderly subjects. Design and participants We studied a random sample of 1444 subjects of the Rotterdam study, and 997 subjects of the Rotterdam Scan study, two population-based cohort studies among elderly individuals aged 55-90 years. Outcome measurements Data on blood pressure and hypertension were obtained, and serum thyroid parameters, D2-Thr92Ala, D2-ORFa-Gly3Asp and TSHR-Asp727Glu polymorphisms were determined. Results In contrast to previous findings, no consistent and/or significant associations were found between serum TSH and FT4 and blood pressure in both cohorts. In addition, the D2-Thr92Ala, D2-ORFa-Gly3Asp and TSHR-Asp727Glu polymorphisms were not associated with blood pressure or the risk of hypertension. Conclusions In two large populations of elderly subjects, neither serum thyroid parameters nor polymorphisms in the type 2 deiodinase and the TSH receptor, were associated with blood pressure or the presence of hypertension. Our data suggest that thyroid function is not an important determinant of hypertension in elderly Dutch subjects.