FVC, FEV₁ and FEV₁ / FVC % in Hypothyroid Female and their Relationships with Thyroid Hormones

Abstract

Background: Hypothyroidism is a common hormonal disorder affecting various organs including lungs. It may be associated with respiratory symptoms and can decrease lung function.

Objective: To observe FVC, FEV₁ and FEV₁/ FVC % in hypothyroid female patients.

Methods: This crosssectional study was carried out in the Department of Physiology, BSMMU, Dhaka, from 1st July 2008 to 30th June 2009 on 60 hypothyroid female patients of 30-50 years age (Group B). For comparison, 30 age and BMI matched apparently healthy subjects (Group A) were also studied. Based on receiving treatment, hypothyroid patients were divided into B₁ (untreated patients on their 1st day of diagnosis) and B₂ (patients treated for at least 12-18 months). They were selected from the Out Patient Department of Endocrinology wing of department of Medicine, BSMMU, Dhaka. Serum TSH and FT₄ levels were measured by Microparticle Enzyme Immunoassay (MEIA) principle in AxSYM system. The FVC, FEV₁, FEV₁/FVC%, of all the subjects were measured by a digital MicroDL spirometer. Data were analyzed by One way ANOVA test, Independent sample t- test and Pearson’s correlation coefficient test.

Results: The mean percentage of predicted values of all the lung function variables in healthy female subjects and treated hypothyroids were within normal ranges. However, all of them were lower in untreated hypothyroids in comparison to those of control and treated hypothyroids.FVC and FEV₁ showed statistically significant (p<0.001) difference and FEV₁/FVC% showed non significant difference . In addition, all the ventilatory variables had negative correlation with serum TSH level and positive correlation with serum FT₄ level and these relationships were statistically significant in control (p<0.001) and treated hypothyroids (p<0.01).

Conclusion: This study reveals that lung function may be lower in untreated hypothyrod patients and correlated with thyroid hormones. Treatment of hypothyroids may reverse this changes.

Key words: FVC, FEV1 , FEV1/FVC%, Hypothyroidism   

DOI: http://dx.doi.org/10.3329/jbsp.v6i1.8084

J Bangladesh Soc Physiol. 2011 June; 6(1): 45-51