[Ambulatory blood pressure monitoring in normotensive patients with subclinical hypothyroidism].
BACKGROUND
Overt hypothyroidism is associated with elevation of diastolic blood pressure; however the association of subclinical hypothyroidism (SH) with arterial blood pressure (ABP) alteration is unknown.


OBJECTIVE
The aim of the present study was to evaluate ambulatory blood pressure monitoring (ABPM), over 24 hours, in normotensive patients with SH in comparison to euthyroid (EU) normotensive individuals.


METHODS
A cross-sectional study was performed with 50 participants (SH = 30 and EU = 20) that did not differ regarding risk factors for hypertension. The ABPM was carried out with a DINAMAPA TM monitor, using the oscillometric method validated by AAMI (Association for the Advancement of Medical Instrumentation) and by the BHS (British Hypertension Society).


RESULTS
The mean serum TSH and FT4 were respectively 6.9 +/- 2.2 microUI/ml and 1.1 +/- 0.2 ng/dl in SH patients. Although there was no difference in the mean values of systolic and diastolic blood pressure between the two groups, there was a positive correlation between the mean values of diastolic blood pressure (DBP) and serum TSH levels in SH patients (r:0.477; p = 0.004). These correlations were detected at daytime (r:0.498; p = 0.002) and sleep-time (r:0.322; p = 0.032) measurements.


CONCLUSIONS
The blood pressure was not different between patients with or without SH; however, the results suggest that the progression of subclinical hypothyroidism to higher levels of TSH may increase the cardiovascular risk by increasing diastolic blood pressure.
Ferreira
Marcia Martins
MM
Faculdade de Medicina, Rio de Janeiro, RJ, Brasil.
Teixeira
Patricia de Fatima dos Santos
Pde F
Mansur
Vera Aleta R
VA
Reuters
Vaneska Spinelli
VS
Almeida
Cloyra Paiva
CP
Vaisman
Mario
M
D000328:Adult; D000704:Analysis of Variance; D018660:Blood Pressure Monitoring, Ambulatory; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology*; D007037:Hypothyroidism / Q000150:complications / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012016:Reference Values; D012307:Risk Factors; D018709:Statistics, Nonparametric; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D013997:Time Factors
D013972:Thyrotropin; D013974:Thyroxine