Background: Chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality with increasing prevalence worldwide. Changes in oxygen tension such as hypoxia, has been found to modulate the release of purine metabolites such as uric acid. Serum uric acid increases significantly during hypoxia. Elevated uric acid levels have been associated with the presence of systemic inflammation and increased cardiovascular risk. Also, it could serve as a non-invasive indicator for COPD severity.
Method: This is a prospective cohort analytic study among COPD in exacerbation patients at Philippine Heart Center. Serum uric acid level determination was done as part of the routine blood tests obtained during admission. Patients were followed-up until discharge and through a telephone conversation 30 days after discharge to determine mortality. Fisher's exact analysis used to determine the association between elevated serum uric acid level and mortality and independent t-test was used to determine the length of hospitalization, ICU stay and NIV use between patients with low and high serum uric acid levels. A p-value of ≤ 0.05 was considered significant.
Results: A total of 159 patients were included in the study. Fifty-seven patients (57 %) were males and forty-three (43 %) were females. The mean age of the study population was 69 years old. Majority of the patients (91%) were smoker, with mean average pack-year-smoker of 25.57+9.03 pack-year. One hundred forty four patients (91%) has no PTB treatment. Majority of the patients (66%) were hypertensive with GOLD Classification C (55 %). Patients with high serum uric acid levels required more prolonged hospitalization with a mean average hospital stay was 16.38+6.58 days and presented higher rates of 30-day mortality. Moreover, patients with high serum uric acid
levels required noninvasive ventilation (NIV) which were both statistically significant (p 0.005 and p <0.001 respectively).
Conclusion: Elevated serum uric acid levels on admission among patients with COPD in exacerbation are associated with increased 30-day mortality and increased risk of NIV use.