The Findings Of A Study Of Subclinical Thyroid Function And Blood Pressure

[Background] The relationship between subclinical hypothyroidism and cardiovascular disease have been widely reported in the literature. However, whether subclinical hypothyroidism is related to elevated blood pressure is still controversial. In order to determine the association between subclinical hypothyroidism and blood pressure, we perform a cross-sectional study and a meta-analysis of related literatures.[Method] Our cross-sectional study consecutively enrolled normal male subjects receiving regular medical check-up with thyroid function test in the health medical center of PUMCH from January,2009to December,2011. Also, a systemic search of databases (MEDLINE [1950to April2012] and EMBASE [1966to April2012) was conducted and a meta-analysis was used to pool the results of the included studies.[Result]10893subjects were included in the cross-sectional study, of which888(8.15%) were subclinical hypothyroidism. When compared with the eurothyroidism, subjects with subclinical hypothyroidism had a significantly higher systolic blood pressure (129.16±16.22mmHg versus126.71±14.53mmHg, p<0.001) and a slightly higher diastolic blood pressure (81.42±11.47mmHg versus80.63±10.86mmHg, p=0.05). Regression analysis relieved that subclinical hypothyroidism was not a risk factor of elevated systolic blood pressure (OR1.141,95%CI0.969～1.343, p=0.113) after adjusted for age and BMI.18studies with46729subjects were included in the meta-analysis. The subclinical hypothyroidism was associated with a higher systolic but not diastolic blood pressure (weighted mean differences of systolic blood pressure,1.45mmHg [95%CI0.46～2.43mmHg, p=0.004]; weighted mean differences of diastolic blood pressure,0.435mmHg [95%CI-0.183～1.054, p=0.168]).[Conclusion] Based on the current evidence, we conclude that subclinical hypothyroidism is a risk factor of elevated systolic blood pressure, which may not be considered as an independent risk fator.