Serum uric acid and clinical outcome of patients with acute exacerbation of chronic obstructive pulmonary disease

Abstract

Introduction: Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide and India contributes a significant and growing percentage of COPD mortality. Chronic hypoxia is a known condition causing tissue inflammation which may lead to an increased uric acid synthesis due to an increased RNA-DNA breakdown. Studies have shown the relationship between uric acid and adverse clinical outcomes in COPD. Data are lacking regarding this from the Indian subcontinent for which this study was undertaken. Materials and Methods: A prospective observational study was carried out at a tertiary respiratory care hospital for approximately 1 year to enroll patients admitted with acute exacerbation of COPD. Patients were divided into two groups with high and normal serum uric acid and were followed up for 30 days from admission. Following clinical outcomes were looked at duration of hospital stay, intensive care unit (ICU) admission, need for noninvasive ventilation (NIV)/invasive mechanical ventilation (IMV), mortality. Results: A total of 135 patients were enrolled (88 with normal and 47 with high serum uric acid levels). Patients with high serum uric acid had longer hospital stay (17.65 ± 4.41 vs. 11.65 ± 4.9 days), higher rates of ICU admission (60% vs. 21%), use of NIV/IMV (95% vs. 57%) and mortality (17% vs. 9%). Negative correlation was seen between serum uric acid and FEV1% predicted values in patients (r = −0.4, P = 0.017). Multiple logistic regression showed that high serum uric acid level was an independent risk factor for worse outcomes in all clinical parameters mentioned above. Conclusion: Serum uric acid is a widely available test which is economical can be used in stratifying the COPD patients who are more prone to adverse outcomes and may need intensive management. This will lead to proper resource utilization and patient management in a developing country like India.