RELATIONSHIP BETWEEN ADMISSION BMI AND POSTHOSPITALIZATION DIFFUSION STUDY ABNORMALITIES IN SURVIVORS OF COVID-19 HOSPITALIZATION

ABSTRACT

SESSION TITLE Post-COVID-19 Outcomes SESSION TYPE Rapid Fire Original Inv PRESENTED ON 10/19/2022 1115 am - 1215 pm PURPOSE: Obesity, a risk factor for severe COVID-19 disease, multiplies the risk of hospitalization and mortality. Its impact in lung disease is mediated by altered inflammatory responses and respiratory mechanics. Studies of lung function among COVID-19 disease survivors have identified reduced TLC and DLCO as prominent changes in this population. Obesity, however, is associated with elevated DLCO in otherwise healthy individuals. The objective of this study was to evaluate whether this relationship was preserved among COVID-19 disease survivors. Additionally, we sought to analyze whether maximum FiO2, peak neutrophil-to-lymphocyte ratio (NLR), diabetes or smoking status had any effect in DLCO. METHODS: The charts of adult patients hospitalized with confirmed SaRS-CoV-2 infection between 3/20/2020 and 12/31/2021 were reviewed. Those who survived and later had a PFT were selected, and 73 patients met these criteria. Eighteen were excluded due to radiographic or prior PFT findings of emphysema (COPD or AATD) or ILD, and missing diffusion study data. Patients were stratified by BMI class. Patient characteristics were compared using ANOVA and Pearson correlation. Other outcomes were analyzed using linear regression. RESULTS: A total of 55 patients were included. Average age was 55.6 years. Average BMI and DLCO were distributed as follows healthy (23.76;16.94), overweight (28.3;17.50), obesity classes I (32.3;18.86), II (37.8;17.68), and III (48.2;24.56). ANOVA shows a significant effect of BMI class on DLCO (F4,50=4.067, p=0.006). A significant positive correlation between BMI and DLCO was observed (r=0.392, p=0.003). When comparing BMI classes, Tukey’s HSD test shows that there was a significant difference only when patients classified as overweight (-22.9, p=0.01), or with obesity classes I (-20.2, p=0.02) or II (-24.0, p=0.005), were individually compared to obesity class 3. Regression analysis showed no significant effect of peak FiO2 (-0.056, p=0.07), NLR (-0.051, p=0.60), diabetes (-0.932, p=0.50), or smoking status (0.764, p=0.505). Overall regression between dependent and independent variables is not significant (F4,50=2.21, p=0.082). CONCLUSIONS: These findings suggest that higher obesity is associated with higher DLCO. This is consistent with the known effect of obesity on diffusion capacity, resulting from increased blood volume in the pulmonary circulation. The relationship was preserved even though most patients had DLCO below the percent predicted, as observed in studies of lung function among COVID-19 survivors. Notably, FiO2 and NLR did not have a significant effect on DLCO. CLINICAL IMPLICATIONS Though patients surviving a COVID-19 hospitalization may have a reduced DLCO, the positive relationship between BMI and DLCO is similar to that observed in otherwise healthy obese individuals. DISCLOSURES No relevant relationships by Mohammad Arabiat No relevant relationships by Justin Horner No relevant relationships by Harold Matos Casano No relevant relationships by Doug McElroy No relevant relationships by Karan Singh No relevant relationships by Michael Smith