Comparison of Serum Uric Acid Levels in Patients with Stable Chronic Obstructive Pulmonary Disease and Patients with Acute Exacerbation

Abstract

Purine breakdown produces uric acid (UA) as a by-product. Serum UA levels have been reported to be higher in hypoxic people, including Chronic Obstructive Pulmonary Disease (COPD) patients. Serum UA has been suggested as a marker for impaired oxidative metabolism, and it is also thought to play a role in the prognosis and evaluation of respiratory disorders such as COPD.

Aim: To compare serum uric acid levels in patients with stable Chronic Obstructive Pulmonary Disease and in patients with acute exacerbation (AE).

Material: Study Design: An observational cross sectional comparative study was conducted which included 25 stable COPD patients and 25 patients with AE of COPD, all of them aged more than 40 years. Serum UA levels were measured and compared between the two groups.

Material and methods: Patients fulfilling inclusion criteria were included in the study after taking informed written consent. Blood sample was taken in plain vial and sent to Biochemistry lab for serum UA analysis. The analysis of serum UA was done using system reagent on Beckman Coulter AU Analyser. Complete blood count, blood urea, serum creatinine, arterial blood gas and oxygen saturation were also measured.

Observation and results: The mean serum UA in the Stable group was 6.19 mg/dL and in AE group was 7.45 mg/ dL. There was a statistically significant difference between the 2 groups in terms of serum UA levels with a p value of 0.021 and the mean serum UA level being highest in the AE group. In this study, statistically significant difference was also found between Stable and AE group in terms of mMRC grading of dyspnea (p< 0.001), Pack years (p< 0.001), pH (p=0.009), pO2 (p< 0.001) and pCO2 (p< 0.001). There was no statistically significant difference between Stable and AE group in terms of age, gender, total leucocyte count, blood urea, serum creatinine and HCO3 Conclusion: Serum UA may be a useful parameter in assessing disease severity and hypoxemia in known COPD patients and may be helpful in early intensive management. Increased serum UA levels denote poor state and bad prognosis. Since serum UA is a simple, inexpensive and readily available routine laboratory test, it can be used in risk stratification in patients with COPD and can help in early management of patients with COPD.