Publication:

Study on comparison of pulmonary function tests among diabetic and non-diabetic patients in a tertiary care hospital

Background Diabetes mellitus (DM) is associated with multiple metabolic derangements which in the long term lead to the damage, dysfunction, and failure of different organs like the eyes, kidneys, nerves, heart, and blood vessels, but pulmonary complications of DM have been less addressed. Microangiopathy in lungs can lead to changes in alveolar function which can manifest themselves as pulmonary function abnormalities. Most of the studies on diabetes mellitus and pulmonary function abnormalities had excluded smokers from the study group. In this study, the study design aimed at determining the effects of diabetes mellitus on pulmonary functions of smokers and non-smokers. The objectives of the study were to determine the pulmonary functions of diabetic study patients and non-diabetic controls using spirometry. Also to compare the pulmonary function changes among diabetics and non-diabetics and to compare the pulmonary function changes among diabetics who are smokers and non-smokers.

Methods Fifty cases, aged more than 35 years, who had DM for more than five years, were selected from the inpatient and outpatient services of a tertiary care hospital. Fifty age and sex matched controls were selected from the healthy non diabetic caregivers of the patients.

Results Diabetic cases had statistically significant reductions in mean FEV1, mean FVC and mean PEFR (as L/min) when compared to non-diabetics. Among non-smokers, 33.33%of diabetics had abnormal PFTs while only 10% of non-diabetics had abnormal PFTs (P = 0.0498). Among the smokers, 73.91% of the diabetics had abnormal PFT’s while only 33.33%of the non-diabetics had abnormal PFTs (P = 0.0054).

Conclusions Diabetes mellitus had a significant impact on pulmonary function tests independent of smoking. Diabetes mellitus predominantly causes restrictive changes in the lung function tests.