Lessons from the Hokkaido COPD cohort study
Nishimura, M.; Makita, H.
Nihon Rinsho. Japanese Journal of Clinical Medicine 74(5): 864-868
2016
ISSN/ISBN: 0047-1852 PMID: 27254960 Document Number: 690825
Hokkaido COPD cohort study is a carefully-designed, well-conducted, prospective observational 10 year-long study, which ended early in 2015. We have obtained a number of clinically-relevant novel findings, some of which are as follows. Severity of emphysema was highly varied even in those individuals whose airflow limitation is comparable. The annual change in forced expiratory volume in 1 second (FEV1) over 5 years was also widely varied with normal distribution among the subjects under appropriate treatment. Some patients maintained their pulmonary function for a long time, and others showed a rapid decline. Emphysema severity, but not pulmonary function, was independently associated with such an inter-subject variation in the annual decline in FEV1. When we explored any biomarkers for predicting the FEV1 decline, a lower leptin/adiponectin ratio alone emerged as an explanatory parameter for the rapid decline, and this was also confirmed in an independent Danish cohort study of different ethnicity. Monitoring of quality of life (QOL), using SGRQ scores, also provided interesting observations. The annual change in total score reflected that of FEV1 decline during the follow-up period. However, activity component in QOL deteriorated in almost all the subjects, while symptom component rather improved in many of the patients under appropriate treatment.