A study on the utility of microalbuminuria as an indicator for the assessment of severity of chronic obstructive pulmonary disease and its co-morbidities

Abstract

Background: Microalbuminuria (MAB) in chronic obstructive pulmonary disease (COPD) reflects generalised endothelial dysfunction as well as systemic inflammation. It is considered a vital marker of early cardiovascular involvement and other systemic involvement in COPD. MAB can serve as a surrogate marker to predict the severity of the disease and other systemic co-morbidities amongst COPD patients. This study was carried out to study the association between MAB with COPD severity and to compare the presence of MAB in COPD patients with and without co-morbidities. Methods: The study included 106 COPD patients diagnosed as per the Global Initiative for Obstructive Lung Disease (GOLD) criteria. Severity was assessed with the help of GOLD staging and modified Medical Research Council Dyspnoea Scale. MAB was assessed by urine albumin–creatinine ratio (UACR) of the spot urinary sample. The presence of comorbidities assessed by history, physical examination, laboratory investigations. Results: MAB was evident in n/N (70.8%) patients. MAB was found in 80.6%, 79.1%, 38.1% and 0% of the patients with GOLD Stage 4, Stage 3, Stage 2 and Stage 1 COPD patients, respectively (P = 0.0001). The mean UACR was significantly higher in severe stages of COPD. A significant association of MAB with co-morbidities such as hypertension, ishaemic heart disease, dyslipidaemia and diabetes mellitus (P < 0.05) was evident. Conclusions: MAB could be a promising biomarker to identify COPD patients with severe disease and who are at risk of developing cardiovascular and other systemic co-morbidities.

Keywords

• chronic obstructive pulmonary disease
• microalbuminuria
• urine albumin–creatinine ratio
• co-morbidities