Darya S. Abdulateef a, Taha O. Mahwi b, Sherwan H. Omer a, and Shadan J. Abdullah c

a Department of Physiology, College of Medicine, University of Sulaimani, Kurdistan Region, Iraq.

b Department of Medicine, College of Medicine, University of Sulaimani, Kurdistan Region, Iraq. 

c Shar Hospital, Ministry of Health, Sulaymaniyah City, Kurdistan Region, Iraq. 

Submitted: 9/7/2020; Accepted: 18/10/2020; Published: 21/12/2021

DOI Link: https://doi.org/10.17656/jsmc.10305 



Overt hypothyroidism affects the cardiovascular system and blood pressure regulation. There is controversy on the relation of subclinical hypothyroidism (SCH) with the cardiovascular system, and this relation is not assessed yet in mild SCH (SCH with TSH < 10 mIU/L).


To find differences in systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure, and pulse rate between mild SCH and Euthyroidism, furthermore to evaluate the relationship of these cardiovascular characteristics.


This prospective case-control study involved 186 participants; 43 mild SCH and 142 Euthyroid. The studied subjects were further subdivided into two groups according to age. Pulse rate and blood pressure (SDP and DBP) were measured, and mean and pulse pressure were calculated. The following biochemical parameters were measured; fasting plasma glucose (FPG) and thyroid function test (TFT; TSH, FT4, FT3, and anti-TPO antibody). The parameters were compared between SCH and Euthyroid groups using Student T-test and the correlation between variables was assessed using Pearson’s correlation, with a P-value ≤ of 0.05 is regarded as significant.


The mean TSH level in the mild SCH group is 5.47 (0.89) mIU/L. Mild SCH has higher DBP compared to Euthyroid subjects (81.93 vs 77.64 mmHg), and in the age group of <35 years, each of the DBP, SBP, and mean pressure were higher in SCH compared to control individual, in this group, there is a significant inverse correlation between FT4 and DBP. And in subjects with >35 years significant inverse correlation exists between FT4 and mean pressure, P < 0.05. No significant association is present between TSH level and pulse rate, blood pressure, and pulse pressure. 


Data of the present study revealed that even mild SCH, is associated with higher DBP compared to Euthyroid subjects and the FT4 level in the SCH has a negative correlation with DBP, while there was no significant correlation between pulse pressure, pulse rate with thyroid function test in subject with mild SCH. Follow-up of mild SCH subjects is recommended for blood pressure assessment.


Systolic blood pressure, Diastolic blood pressure, TSH, FT4, Mild SCH, Euthyroid.


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