Profile and preliminary results of Iranian sub cohort chronic obstructive pulmonary disease (COPD) in Shahrekord PERSIAN cohort in southwest Iran

Chronic obstructive pulmonary disease (COPD) is a chronic and complex respiratory disorder associated with airflow limitation and increased inflammatory response of the lungs to harmful particles. The purpose of this original study was to describe the results and profile of the Shahrekord Prospective Epidemiological Research Studies in IrAN (PERSIAN) regarding COPD in southwestern Iran.

This study of asthma and respiratory diseases is a subcohort of the more extensive cohort study, i.e., Shahrekord PERSIAN cohort, a population-based prospective study on people aged 35–70 years in southwestern Iran (n = 10,075). The sample size of the subcohort was 8500 people. Annual follow-ups (person-year) of the cohort were designed to be conducted up to 2036. The instruments to collect data on various exposures were derived from the questionnaires previously developed in extensive multinational studies (occupational exposures, smoking, housing status, and fuel consumption, history of respiratory and chronic diseases, comorbidity, etc.). The Global Initiative for Chronic Obstructive Lung Disease (GOLD) and the lower limit of normal (LLN) spirometric criteria were used to confirm COPD diagnosis.

The response rate was 93.85%. The mean age of the participants was 49.48 ± 9.32; 47.9% were male, and 52.9% were female; nearly 16% of the population was current smokers; the fuel used by most of the participants for heating the house and cooking was gas. The most common comorbidity among participants was dyslipidemia; 30% of people have three or more comorbidities. According to GOLD and LLN criteria, the Prevalence of COPD was 3.6% and 8.4%, respectively. 4.3% of the participants had a history of chronic lung disease. The group of subjects with COPD had higher mean age, fewer years of schooling, a higher percentage of smokers with a smoking history of 10 or more pack years. 4.6% of patients had a history of chronic lung disease, 17.6% had a history of asthma in childhood, and 5.2% had a family history of respiratory and pulmonary diseases.

Epidemiological research is necessary to create an appropriate framework to fight COPD. This framework requires a better description of men and women at risk of developing COPD and describing people with early-stage illnesses.