Impact of thyroid hormones and serum endothelin levels on pediatric asthma control: a case-control study of an Indian population.

BACKGROUND

Asthma severity is influenced by various immunomodulators; however, the specific roles of thyroid hormones and endothelin in childhood asthma in the South Indian population remain unexplored.

PURPOSE

This study investigated the impact of thyroid hormone and endothelin levels on asthma control among children in South India.

METHODS

We divided 90 subjects aged 10-15 years into 3 groups as categorized by the Global Initiative for Asthma guidelines: 30 healthy children, 30 patients with well-controlled asthma, and 30 patients with poorly controlled asthma. Fasting blood samples were collected to analyze endothelin levels and thyroid function. Pulmonary function tests were performed using a portable spirometer to assess forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and the FEV1/FVC ratio.

RESULTS

Thyroid-stimulating hormone (TSH) levels were significantly elevated in the well-controlled (4.66±1.91 mIU/L) and poorly controlled (6.51±4.04 mIU/L) asthma groups versus the control group (P<0.001). Similarly, endothelin levels showed a marked increase (4.65±0.38 pg/mL vs. 18.51±6.13 pg/mL), with the poorly controlled group exhibiting the highest levels (P<0.001). A strong negative correlation was observed between FEV1/FVC% and serum endothelin levels (r=-0.76) on a Pearson correlation analysis.

CONCLUSION

This study revealed a strong association between endothelin levels, the FEV1/FVC ratio, and TSH levels. These findings suggest that serum endothelin level could serve as a potential surrogate marker of asthma severity.