Letter to the editor Date 2012/September/8
Chronic obstructive pulmonary disease is a comorbidity for peptic ulcer bleeding Running head: chronic obstructive pulmonary disease
Shih-Wei Lai, MD1,2;Kuan-Fu Liao, MD and MS3,4,5
1School of Medicine, China Medical University, Taichung, 404, Taiwan
2Department of Family Medicine, China Medical University Hospital, Taichung, 404, Taiwan
3Department of Internal Medicine, Taichung Tzu Chi General Hospital, Taichung, 427, Taiwan
4School of Medicine, Tzu Chi University, Hualien, 970, Taiwan
5Department of Health Care Administration, Central Taiwan University of Science and Technology, Taichung, 406, Taiwan
(The first two authors contributed equally to this study.) Corresponding author:
Kuan-Fu Liao, MD and MS
Department of Internal Medicine, Taichung Tzu Chi General Hospital, No.66, Sec. 1, Fongsing Rd., Tanzih Township, Taichung County 427, Taiwan
Phone: 886-4-2205-2121 Fax: 886-4-2203-3986
E-mail: [email protected]
To editor,
One cohort study published in Aliment Pharmacol Ther has shown that after controlling for possible confounding factors, patients with chronic obstructive pulmonary disease (COPD) had a 1.9-fold risk of developing peptic ulcer bleeding (95% CI 1.73-2.17).1 To the contrary, one case-control study using the UK-based
General Practice Research Database, COPD was not associated with peptic ulcer (OR = 1.24, 95% CI = 0.92-1.66).2 However, smoking and corticosteroid use, two
well-established risk factors for peptic ulcer bleeding,3 could not be completely addressed
in this key paper. Smoking is well-known as a risk factor for COPD, but the authors have mentioned that approximately 25–45% of COPD patients have never smoked.4
However, the smoking prevalence was high in Taiwan (46.8% in men and 4.3% in women).5 We estimated the smoking percentage was about 25.7%-35.1% among
COPD men in this key study. Because of an inherent limitation of Taiwan National Health Insurance database, smoking could not be included for further analysis. Oral systemic or inhaled corticosteroids are commonly prescribed drugs for treating COPD patients. In this key study, only 6.2% of COPD patients had ever used corticosteroids.1 We think this number could be underestimated. That was why
corticosteroids use could not reach a statistic significance (HR = 1.06, 95%CI = 0.85– 1.33).1 Moreover, what other treated drugs did they use among 93.8% of COPD
patients could not be shown in this key paper.
Because of lack of comprehensive data about smoking and corticosteroids use, whether COPD has an absolute effect on peptic ulcer bleeding or a relative effect mediated by smoking and corticosteroids use could not be determined in this key paper. To our opinion, COPD could only be regarded as a comorbid condition at
present, not a risk factor for peptic ulcer bleeding. Thus, more prospective studies with COPD subjects without smoking are required to definitively elucidate this issue.
Conflict of Interest Statement: The authors disclose no conflicts of interest.
REFERENCES
1. Huang KW, Luo JC, Leu HB, et al. Chronic obstructive pulmonary disease: an independent risk factor for peptic ulcer bleeding: a nationwide population-based study. Aliment Pharmacol Ther 2012; 35: 796-802.
2. Schneider C, Jick SS, Bothner U, Meier CR. Reflux disease, gastrointestinal ulcer or weight loss in patients with COPD. COPD 2010; 7: 172-8.
3. Weil J, Langman MJ, Wainwright P, et al. Peptic ulcer bleeding: accessory risk factors and interactions with non-steroidal anti-inflammatory drugs. Gut 2000; 46: 27-31.
4. Salvi SS, Barnes PJ. Chronic obstructive pulmonary disease in non-smokers.
Lancet 2009; 374: 733-43.
5. Wen CP, Levy DT, Cheng TY, Hsu CC, Tsai SP. Smoking behaviour in Taiwan, 2001. Tob Control 2005; 14 Suppl 1: i51-5.
