Spirometric Evaluation of Pulmonary Expiratory Flow Volume and Flow Rate in Patients with Clinical Hypothyroidism at a Tertiary Care Hospital, West Bengal, India: A Case-control Study

Abstract

Introduction: Hypothyroidism is defined as a clinical condition caused by insufficient thyroid hormone secretion from the thyroid gland as a result of structural or functional defects in thyroid hormone production. Hypothyroidism can impair respiratory function and cause ventilation problems. Spirometry is used to assess pulmonary function in patients with thyroid disorders because low thyroid hormone levels can cause bronchial hyperactivity and obstructive pulmonary disease. Aim: To find out the changes of spirometric parameters in clinical hypothyroid patients compared to apparently healthy individuals. Materials and Methods: The study was a case-control study conducted in the Department of Physiology of Burdwan Medical College and Hospital on 50 cases and 50 apparently healthy subjects. Inclusion criteria were diagnosed cases of clinical hypothyroidism, Body Mass Index (BMI) under 30 kg/ m2, and age between 20 to 50 years. Serum TSH and free T4 (FT4) were measured by Quantitative EIA method using RFCL- manufactured commercial “ELISCAN-TSH”-kitand“ELISCAN- Ft4”-kit. Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 second (FEV1), FEV1/FVC, Forced Expiratory Flow (FEF) of 25-75%, and Peak Expiratory Flow Rate (PEFR) parameters of pulmonary function test were tested by RMS Helios 401 Spirometer. Pearson’s two-tailed correlation study and student independent-test were done for analysis. Results: The present study showed that spirometric parameters FEV1, FVC, FEV1/FVC, PEFR and FEF25%-75% were significantly decreased in clinical hypothyroidism compared to control. Mean values of parameters of FEV1, FVC, FEV1/FVC, PEFR and FEF25%-75% in clinical hypothyroid cases were 85.30%, 92.42%, 90.70%, 74.86%, and 75.63%, respectively which were significantly (p<0.001) decreased compared to that of healthy individuals. Conclusion: This study concluded that clinical hypothyroidism causes significant changes in respiratory function. Thus, a proper knowledge in respect to this infection would help in management of these patients in time.