A study of the relationship between serum TSH level and blood pressure

Objective To investigate the relationship between different levels of TSH and blood pressure in the subjects with subclinical hypothyroidism and euthyroid.Methods 1319 subjects were carried out a questionnaire survey,blood pressure,height,and body weight measurement.Blood samples were taken in the fasting state to test serum TSH,fasting plasma glucose,and insulin.FT3 and FT4 were further examined if TSH was abnormal.Subjects were divided into euthyroid group and subclinical hypothyroidism group.Euthyroid group was further divided into three groups:group A(TSH 0.3～0.99 mIU/L),group B(TSH 1.0～1.9 mIU/L),and group C(TSH 1.91～4.8 mIU/L).The relationship between different levels of serum TSH and systolic and diastolic blood pressure was analyzed.Results Different levels of serum TSH had no relation with systolic and diastolic blood pressure.The prevalence of hypertension in subclinical hypothyroidism group was significantly higher than euthyroid group in females(41.3% VS.25.6%,P0.05).The risk of hypertension in subclinical hypothyroidism group was significantly higher than that in the euthyroid group after adjusted for age,gender,smoking status,HOMA-IR,and BMI(OR=1.753,95%CI 1.067～2.879,P=0.027).This association was stronger in females(OR=3.545,95%CI 1.576～7.975,P=0.004),but there was no statistical significance in males.Within normal range of TSH,Both SBP and DBP were similar among three groups.The prevalence and risk of hypertension were also similar among three groups.Conclusion Subclinical hypothyroidism could increase the risk of hypertension.The prevalence of hypertension in subclinical hypothyroidism group was significantly higher than euthyroid group in females.Change of TSH in normal range did not affect blood pressure.