Serum Uric Acid Levels and Uric Acid/Creatinine Ratios in Stable Chronic Obstructive Pulmonary Disease (COPD) Patients: Are These Parameters Efficient Predictors of Patients at Risk for Exacerbation and/or Severity of Disease?

Abstract

BackgroundSerum uric acid (sUA) levels were previously found to be correlated with hypoxic states. We aimed to determine the levels of sUA and sUA/creatinine ratios in stable COPD patients and to evaluate whether sUA level and sUA/creatinine ratio can be used as predictors of exacerbation risk and disease severity.Material/MethodsThis cross-sectional study included stable COPD patients and healthy controls. The sUA levels and sUA/creatinine ratios in each group were evaluated and their correlations with the study parameters were investigated. ROC analyses for exacerbation risk and disease severity were reported.ResultsThe study included 110 stable COPD patients and 52 healthy controls. The mean sUA levels and sUA/creatinine ratios were significantly higher in patients with COPD compared to healthy controls. The most common comorbidities in COPD patients were hypertension, diabetes, and coronary artery disease. While sUA levels were significantly higher in patients with hypertension (p=0.002) and malignancy (p=0.033), sUA/creatinine ratios was higher in patients with malignancy (p=0.004). The ROC analyses indicated that sUA/creatinine ratios can be more useful than sUA levels in predicting exacerbation risk (AUC, 0.586 vs. 0.426) and disease severity (AUC, 0.560 vs. 0.475) especially at higher cut-off values, but with low specificity.ConclusionsOur study suggested that sUA levels and sUA/creatinine ratios increased in patients with stable COPD, especially among patients with certain comorbidities compared to healthy controls. At higher cut-off values, sUA levels and especially sUA/creatinine ratios, might be useful in predicting COPD exacerbation risk and disease severity. Also, their association with comorbidities, especially with malignancy and hypertension, may benefit from further investigation.

Chronic Obstructive Pulmonary Disease is Associated with a Higher Level of Serum Uric Acid. A Systematic Review and Meta-Analysis

“…A total of 20 articles were retrieved for full-length article review and 12 articles were excluded at this stage as they did not report the level of serum uric acid among participants with and without COPD. Finally, eight studies [12][13][14][15][16][17][18][19] with 1,612 participants were eligible for the meta-analysis. The literature retrieval, review and selection process are shown in Figure 1.…”

“…The increased level of serum uric acid is thought www.journals.viamedica.pl to be a consequence of increased purine catabolism in the presence of tissue hypoxia [11]. The current systematic review and meta-analysis was conducted to compare serum uric acid level between patients with COPD, a common hypoxemic disorder, and individuals without COPD [12][13][14][15][16][17][18][19].…”

Altered uric acid metabolism in isolated colonic Crohn's disease but not ulcerative colitis

“…Uric acid elimination occurs mainly in urine, which is dependent on renal function. Previous studies have used uric acid to creatinine ratio as a surrogate marker to investigate the relationship between uric acid and other outcomes of interest, and it is a better predictor of incident chronic kidney dysfunction than uric acid alone . These studies highlight the advantage of implementing uric acid to creatinine ratio as it more precisely reflects the endogenic uric acid production.…”

Sleep Duration is Inversely Associated with Serum Uric Acid Concentrations and Uric Acid to Creatinine Ratio in an Elderly Mediterranean Population at High Cardiovascular Risk

“…Uric acid is a terminal product of purine degradation, and high levels of circulating uric acid have been associated with gout, type 2 diabetes (T2D), and renal and cardiovascular diseases [1]. Recently, a higher serum uric acid (SUA) to creatinine ratio was associated with an increased risk of metabolic syndrome [2], and predicted chronic kidney disease incidence in T2D patients [3] and chronic obstructive pulmonary disease as compared to uric acid alone [4]. Growing evidence also suggests that elevated SUA levels are frequently identified in patients with obstructive sleep apnea [5], possibly due to elevations in catecholamine levels [6] and intermittent hypoxia.…”