Left ventricular diastolic and pulmonary dysfunction in patients with sub-clinical hypothyroidism; A case- control study

Authors : Amira H Allam, Mohamed S Darwish

DOI : 10.18231/j.ijirm.2019.057

Volume : 4

Issue : 4

Year : 2019

Page No : 252-257

Introduction: Subclinical hypothyroidism has been associated with adverse metabolic, cardiovascular, neuromuscular, and cognitive effects and has been shown to have a detrimental impact on quality of life. Though there are many literatures regarding the effect of hypothyroidism on pulmonary function but few studies revealing the influence of subclinical hypothyroidism on pulmonary functions are found.

Aim of the Study: To evaluate the left ventricular diastolic dysfunction in individuals with subclinical hypothyroidism and to evaluate their relation to (FEV1%, FVC%, FEF 25-75%).

Materials and Methods:  This is a case-control study involving ninety five (95) subjects who were divided into 2 groups; 50 cases with higher than normal TSH (>4.5 mU/L) but lower than 10mU/L with normal FT3 and FT4 (group 1), group 2 with normal levels of TSH, FT3 and FT4. The following was done to all subjects; TSH, FT3 and FT4 by Eliza, echocardiography for left ventricular diastolic dysfunction assessment and spirometry.

Results: There  was Lower TSH, FT3, reduced E wave velocity, E/A ratio with increased A wave velocity, prolonged deceleration time (DT) and intra-ventricular relaxation time  (IVRT) , lower (FEV1, FVC, FEF25-75) % in group 1. TSH showed a negative correlation with E wave velocity, E/A ratio and the three pulmonary function indices with a strong positive correlation with IVRT. IVRT has a moderate negative correlation with FVC%. Correlations between other echocardiograpic parameters of LV diastolic dysfunction and pulmonary function indices were weak.

Conclusion: Subclinical hypothyroidism patients are more prone to left ventricular diastolic dysfunction so they should be screened by Doppler echocardiography for early diagnosis and management. Although the pulmonary function alterations in subclinical hypothyroidism are mild, they should not be ignored. Further studies are needed to decide whether these changes are enough to establish thyorxine replacement therapy.

Keywords: Diastolic, Dysfunction, Pulmonary, Subclinical, Hypothyroidism.


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