ALB and chronic obstructive pulmonary disease: The results showed that low albumin and uric acid levels were the risk factors for type II respiratory failure in acute exacerbation of COPD patients, and the differences were statistically significant (albumin: SMD = −2.03, 95% CI: −2.81, −1.26; uric acid: SMD = −1.28, 95% CI: −1.41, −1.15).