Association Between Urinary Albumin-to-Creatinine Ratio and COPD Severity: A Cross-Sectional Study in Nepa

Abstract

Background
Chronic Obstructive Pulmonary Disease (COPD) is a leading cause of morbidity and mortality worldwide. Systemic inflammation in COPD may cause endothelial dysfunction, potentially increasing urinary albumin-to-creatinine ratio (UACR), a marker of microvascular damage. This study aimed to investigate the association between UACR and COPD severity based on GOLD classification, to evaluate its potential as an independent biomarker for risk stratification and prognosis in COPD patients.
Methods
This cross-sectional study was conducted at Tribhuvan University Teaching Hospital, Nepal, from May to October 2023. A total of 70 clinically stable COPD patients were recruited using purposive sampling. Severity was classified according to GOLD 2023 guidelines. UACR was measured from a single spot urine sample. Statistical analysis was performed using SPSS v20, with Kruskal-Wallis and Spearman’s correlation tests.
Results
The median UACR increased progressively with COPD severity: GOLD 1 (15.2 mg/g), GOLD 2 (21.8 mg/g), GOLD 3 (38.5 mg/g), and GOLD 4 (61.3 mg/g). Significant differences in UACR were observed among severity groups (p<0.001). A strong positive correlation (r=0.68, p<0.001) was found between UACR and GOLD staging. UACR also showed significant associations with exacerbation frequency, CAT score, and mMRC dyspnea grade. No significant difference was observed between males and females. Median UACR in frequent exacerbators was 47.6 mg/g vs. 19.4 mg/g in infrequent ones (p=0.002).
Conclusions
UACR significantly correlates with COPD severity, indicating its potential as a non-invasive biomarker for disease progression and systemic involvement in COPD patients.