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

Introduction: we aimed to investigate the associations of body mass index (BMI) and oxygen saturation with chronic obstructive pulmonary disease (COPD) grade in COPD patients. Materials and methods: 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. Results and conclusion: 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.