Correlation of BMI and oxygen saturation in stable COPD in Northern India

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is associated with clinically relevant extra pulmonary manifestations; one of them is weight loss. However, there are very few studies from North India available in relation to body mass index (BMI) and Oxygen saturation (SpO(2)) with COPD. AIMS: To study the prevalence of undernutrition among stable COPD patients and correlation of COPD severity with SpO(2) and BMI. SETTINGS AND DESIGN: A prospective study was carried out at a tertiary care hospital. SUBJECTS AND METHODS: COPD patients were diagnosed and staged as per global initiative for chronic obstructive lung disease (GOLD) guidelines. SpO(2) was measured using pulse oxymeter and BMI categorization was done as per new classification for Asian Indians (2009). Statistical analysis was done using Statistical Package for Social Sciences Version 15.0. RESULTS: Out of 147 COPD patients, 85 (57.8%) were undernourished. The prevalence of undernourished BMI was 25%, 50.8%, 61.7%, and 80% in stage I, II, III and IV respectively; statistically significant (P < 0.050). The mean SpO(2) was 95.50 ± 1.41, 95.05 ± 2.42, 94.37 ± 2.28 and 93.05 ± 1.39 in stage I, II, III and IV respectively; statistically significant (F = 4.723; P = 0.004). CONCLUSIONS: The overall prevalence of under nutrition among COPD patients was 57.8%. With increasing COPD stage the BMI and median SpO(2) value decreased in progressive manner. Association of SpO(2) and COPD stages could be explored further in order to suggest an additional marker of disease severity that would add a new dimension in the management of COPD.