Correlation of Ischemia Modified Albumin with Clinicophysiological Profile of Stable COPD Patients: Hospital Based Observational study

INTRODUCTION: As per the Global Burden of Disease study (2017), there is a recent rise in trend of non-communicable diseases (NCDs) like ischemic heart disease, stroke, and chronic obstructive pulmonary disease (COPD). Among the non-communicable diseases, Chronic Obstructive Pulmonary Disease is of major concern because of its increasing prevalence and high morbidity not only due to pulmonary manifestations but also due to systemic manifestations. AIMS AND OBJECTIVES: AIMS: To evolve a biomarker that would compliment clinical assessment of disease morbidity, prognosis and quality of life related to COPD. BROAD OBJECTIVE: To characterize the clinico-physiological profile of subjects with stable COPD attending chest clinic of a tertiary care centre. SPECIFIC OBJECTIVES: 1. To compare Ischemia Modified Albumin with BODE index as a predictor of mortality due to COPD. 2. To compare Ischemia Modified Albumin with COPD related quality of life as measured by St.George’s Respiratory Questionnaire. 3. To identify factors associated with high Ischemia Modified Albumin among subjects with stable COPD. METHODOLOGY Study Design: Prospective observational study. Study Population: Eligible subjects with stable COPD attending outpatient clinic of the department of Tuberculosis and Respiratory Diseases, PSG IMSR. Inclusion Criteria: 1. Physician diagnosed COPD with age at onset of illness 40 years and above. 2. Smoking history with more than 10 pack years. 3. Willing to participate in the study adhering to its protocol. Exclusion criteria: 1. History suggestive of asthma. 2. History of past or coexisting malignancy, connective tissue disorders and other chronic inflammatory disorders. 2. History of Ischemic heart disease, ischemic stroke, pulmonary embolism. 3. Coexisting poorly controlled Diabetes Mellitus [ HbA1c-8.5%] 4. Pneumonia, active tuberculosis. 5. Mental status not competent enough to give consent for the study. LIMITATIONS: The study has its own limitations. Though the proposed sample size was 60, we were unable to reach the targeted sample size because of the current covid-19 pandemic. An observational study overestimates the diagnostic value of a biomarker. Cut-off ranges of a biomarker like which are used in interventional study provides clinically usual data. Interventional studies, in which therapy is guided by cut-off ranges of a biomarker and in which efficacy is the outcome measure, have the potential to provide more clinically relevant data. Financial constraints limited us from performing ELISA method of IMA estimation which is considered more accurate. Estimation of serum albumin and using correction formula for the serum albumin levels is needed for accurate measurement of ischemia modified albumin, which is not done due to financial constraints. Another limitation is, this study does not have controls, a case control study would have given a clear cut differentiation of those with and without ischemia, which is lacking in this study. Another limitation was that no female subjects were recruited since the inclusion criteria included subjects with smoking with pack years of ≥ 10. CONCLUSION: Our study has found that serum ischemia modified albumin has got significant correlation with clinic physiological profile of stable COPD patients. Serum IMA as a biomarker appears to be more reliable, less expensive and more relevant for use in clinical practice. Even though IMA is more reliable, it is not considered as a specific biomarker for COPD, as it is elevated in other ischemic conditions limiting its utility in patients with COPD and underlying co morbidities like ischemic heart disease, ischemic stroke, pulmonary embolism, diabetes etc. We recommend larger studies with higher sample size which could establish the relationship between IMA and clinicophysiological variables of COPD. Such studies could ultimately improve our current way of diagnosing COPD patients who are prone to exacerbations