Lung function decline rates according to GOLD group in patients with chronic obstructive pulmonary disease

Abstract

Background

Since the Global Initiative for Chronic Obstructive Lung Disease (GOLD) groups A–D were introduced, the lung function changes according to group have been evaluated rarely.

Objective

We investigated the rate of decline in annual lung function in patients categorized according to the 2014 GOLD guidelines.

Methods

Patients with COPD included in the Korean Obstructive Lung Disease (KOLD) prospective study, who underwent yearly postbronchodilator spirometry at least three times, were included. The main outcome was the annual decline in postbronchodilator forced expiratory volume in 1 second (FEV₁), which was analyzed by random-slope and random-intercept mixed linear regression.

Results

A total 175 participants were included. No significant postbronchodilator FEV₁ decline was observed between the groups (−34.4±7.9 [group A]; −26.2±9.4 [group B]; −22.7±16.0 [group C]; and −24.0±8.7 mL/year [group D]) (P=0.79). The group with less symptoms (−32.3±7.2 vs −25.0±6.5 mL/year) (P=0.44) and the low risk group (−31.0±6.1 vs −23.6±7.7 mL/year) (P=0.44) at baseline showed a more rapid decline in the postbronchodilator FEV₁, but the trends were not statistically significant. However, GOLD stages classified by FEV₁ were significantly related to the annual lung function decline.

Conclusion

There was no significant difference in lung function decline rates according to the GOLD groups. Prior classification using postbronchodilator FEV₁ predicts decline in lung function better than does the new classification.

Keywords:

• annual lung function decline
• chronic obstructive pulmonary disease
• GOLD 2014

Acknowledgments

The authors thank Woo Jin Kim, Kwang Ha Yoo, Sei Won Lee, Jae Seung Lee, Chin Kook Rhee, and Hyun-Jeong Lee.

Disclosure

The authors report no conflicts of interest in this work.