Ismail Polat Canbolat1, Erdal Belen2, Akif Bayyigit3, Aysen Helvaci4, Kadriye Kilickesmez5. 1. Department of Cardiology, Istanbul Bilim University. 2. Department of Cardiology. 3. Department of Internal Medicine, Okmeydani Training and Research Hospital. 4. Department of Cardiology, Biruni University. 5. Department of Cardiology, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Turkey.
Abstract
BACKGROUND: Subclinical hypothyroidism is the most common thyroid dysfunction in the general population. The relationship between overt thyroid dysfunction and hypertension is generally understood. Besides high blood pressure, non-dipper hypertension is known to increase cardiovascular risk. Our aim is to investigate daily blood pressure changes and the frequency of non-dipping patterns in patients with subclinical hypothyroidism. METHODS: Forty-nine patients without hypertension with subclinical hypothyroidism were compared with 50 healthy sex- and age-matched controls using ambulatory blood pressure monitoring. RESULTS: Thyroid-stimulating hormone (TSH) levels were significantly higher in the subclinic hypothyroidism group, and there was no difference between free triiodothyronine (FT3) and free thyroxine (FT4) levels which could be predicted as a result of the study design. Levels of mean diastolic, daytime diastolic, nighttime diastolic and nighttime systolic blood pressure were significantly higher in the subclinic hypothyroidism group (p = 0.001 for mean, daytime and nighttime diastolic and p = 0.01 for nighttime systolic). Diastolic non-dipping occurred more frequently in the subclinic hypothyroidism group [subclinical hypothyroidism group 24 patients (49%), control group 13 patients (26%), p = 0.01]. On multivariate analysis, subclinical hypothyroidism was independently associated with diastolic non-dipping (95% confidence interval 1.162-8.053, odds ratio 1.182, p = 0.024). CONCLUSIONS: Our study found that both the frequency of diastolic non-dipping pattern and diastolic blood pressure increase with subclinical hypothyroidism. Therfore, it would appear that searching for non-dipping pattern can add valuable information for patients with subclinical hypothyroidism.
BACKGROUND:Subclinical hypothyroidism is the most common thyroid dysfunction in the general population. The relationship between overt thyroid dysfunction and hypertension is generally understood. Besides high blood pressure, non-dipper hypertension is known to increase cardiovascular risk. Our aim is to investigate daily blood pressure changes and the frequency of non-dipping patterns in patients with subclinical hypothyroidism. METHODS: Forty-nine patients without hypertension with subclinical hypothyroidism were compared with 50 healthy sex- and age-matched controls using ambulatory blood pressure monitoring. RESULTS: Thyroid-stimulating hormone (TSH) levels were significantly higher in the subclinic hypothyroidism group, and there was no difference between free triiodothyronine (FT3) and free thyroxine (FT4) levels which could be predicted as a result of the study design. Levels of mean diastolic, daytime diastolic, nighttime diastolic and nighttime systolic blood pressure were significantly higher in the subclinic hypothyroidism group (p = 0.001 for mean, daytime and nighttime diastolic and p = 0.01 for nighttime systolic). Diastolic non-dipping occurred more frequently in the subclinic hypothyroidism group [subclinical hypothyroidism group 24 patients (49%), control group 13 patients (26%), p = 0.01]. On multivariate analysis, subclinical hypothyroidism was independently associated with diastolic non-dipping (95% confidence interval 1.162-8.053, odds ratio 1.182, p = 0.024). CONCLUSIONS: Our study found that both the frequency of diastolic non-dipping pattern and diastolic blood pressure increase with subclinical hypothyroidism. Therfore, it would appear that searching for non-dipping pattern can add valuable information for patients with subclinical hypothyroidism.
Authors: Nicolas Rodondi; Wendy P J den Elzen; Douglas C Bauer; Anne R Cappola; Salman Razvi; John P Walsh; Bjørn O Asvold; Giorgio Iervasi; Misa Imaizumi; Tinh-Hai Collet; Alexandra Bremner; Patrick Maisonneuve; José A Sgarbi; Kay-Tee Khaw; Mark P J Vanderpump; Anne B Newman; Jacques Cornuz; Jayne A Franklyn; Rudi G J Westendorp; Eric Vittinghoff; Jacobijn Gussekloo Journal: JAMA Date: 2010-09-22 Impact factor: 56.272
Authors: G Mancia; A Zanchetti; E Agabiti-Rosei; G Benemio; R De Cesaris; R Fogari; A Pessina; C Porcellati; A Rappelli; A Salvetti; B Trimarco; E Agebiti-Rosei; A Pessino Journal: Circulation Date: 1997-03-18 Impact factor: 29.690