Impact of gastro-oesophageal reflux disease symptoms on chronic obstructive pulmonary disease exacerbation

Kunihiko Terada ¹, Shigeo Muro ^1*, Susumu Sato ¹, Tadashi Ohara ¹, Akane Haruna ¹, Satoshi Marumo ¹, Daisuke Kinose ¹, Emiko Ogawa ¹, Yuma Hoshino ², Akio Niimi ¹, Tadayuki Terada ³ and Michiaki Mishima ¹

¹ Department of Respiratory Medicine, Kyoto University, Japan
² Department of Experimental Therapeutics, Kyoto University Hospital, Japan
³ Terada Clinic, Respiratory Medicine and General Practice, Himeji City, Japan

^* To whom correspondence should be addressed. E-mail: smuro{at}kuhp.kyoto-u.ac.jp.

Accepted 16 April 2008

Abstract

Background: The association between gastro-oesophageal reflux disease (GORD) and chronic obstructive pulmonary disease (COPD) exacerbation has so far remained unclear.

Objective: To prospectively establish the clinical significance of GORD symptoms on exacerbation.

Methods: In total, 82 COPD patients and 40 age-matched controls were enrolled in this study. Symptoms were evaluated by a questionnaire using the Frequency Scale for the Symptoms of GORD (FSSG). COPD patients were prospectively surveyed for 6 months, and episodes of exacerbation were identified using a diary based on modified Anthonisen's criteria. Exhaled breath condensate (EBC) pH was measured in both groups, and induced sputum was evaluated in COPD patients.

Results: Positive GORD symptoms were reported in 22 (26.8%) COPD patients and five (12.5%) controls (p = 0.10). The frequency of exacerbations was significantly associated with the FSSG score (p = 0.03, r = 0.24, 95% confidence interval (CI) = 0.02-0.43). Multiple regression analysis revealed that GORD symptoms were significantly associated with the occurrence of exacerbations (p < 0.01; relative risk (RR) = 6.55, 95% CI = 1.86- 23.11). EBC pH was inversely correlated with FSSG score in both groups (p = 0.01, r =-0.37, 95% CI = -0.55 to -0.14 in COPD patients, and p < 0.01, r = -0.45, 95% CI = -o.67 to -0.16 in control subjects).

Conclusions: GORD symptoms were identified as an important factor associated with COPD exacerbation.