Analysis of risk factors for chronic obstructive pulmonary diseases in Okinawa, Japan

Introduction: The cases of COPD (Chronic bronchitis, Emphysema) have recently been increase on the world wide. COPD is the fourth leading cause of death in the world. Okinawa has high SMR of COPD in Japan.

Objectives: The purpose of this study is to clarify contributing factors of high mortality of COPD in Okinawa.

Methods: This cross-sectional study was conducted in 2007, by using a self-administered questionnaire in Okinawa. The analysis was based on the data from 518 subjects aged 60 to 84 years who participated in the baseline survey which was conducted with residents (aged 55-84) of 10 urban communities and 10 rural (isolated islands) communities - a total of 5,910 by the authors.

Results: A significant difference was seen for age 4.4(95%CI: 4.3-4.5) and a tobacco use period 3.5 (0.3-6.7), but was not seen for COPD related symptoms. COPD symptoms were new cases in 2007 which were not the cases in 2002. They were having coughs catching a cold (21.8%), bringing up phlegm and wheezing having a cold(15.0%) and having difficulty in catching breath when going up a slope (8.4%).

In 2007, chronic bronchitis was 23 cases (4.5%) and pulmonary emphysema was 10 cases (2.0%), 6 cases in the pulmonary emphysema were added newly.

Conclusion: In conclusion, our results did not contribute to the evidence that clear contributing factors of high mortality of COPD in Okinawa. It was suggested that the risk factors of the pulmonary emphysema was different from chronic bronchitis.