Associations of body mass index and oxygen saturation with chronic obstructive pulmonary disease grade in patients

we aimed to investigate the associations of body mass index (BMI) and oxygen saturation with chronic obstructive pulmonary disease (COPD) grade in COPD patients. the clinical data of 105 COPD patients admitted to and treated in our hospital during January 2021 and January 2022 were acquired for a retrospective analysis, and grade 1 group [n = 15, subjects presenting forced expiratory volume in one second (FEV1) ≥ 80 % of the predicted value], grade 2 group (n = 32, those with FEV1 ≥ 50 % and < 80 % of the predicted value), grade 3 group (n = 34, those with FEV1 ≥ 30 % and < 50 % of the predicted value), and grade 4 group (n = 24, those with FEV1 < 30 % of the predicted value or with FEV1 < 50 % of the predicted value and concomitant respiratory failure) were set up based on COPD grade. the BMI of the 105 patients was 20.39 ± 3.31 kg/m² on average, and it showed differences of statistical significance regarding the subjects with varying COPD grades (p < 0.05). The oxygen saturation was 89.98 ± 4.04 on average in the 105 patients, and it also displayed statistically significant differences among patients with different grades of COPD (p < 0.05). According to pairwise comparison, grade 1 group exhibited the highest oxygen saturation, followed by grade 2, 3, and 4 groups in turn (p < 0.05). Both BMI and oxygen saturation had negative correlations with COPD grade (p < 0.05). In COPD patients, COPD grade is negatively correlated with BMI and oxygen saturation.