Metabolic Syndrome in Early Chronic Obstructive Pulmonary Disease: Gender Differences and Impact on Exacerbation and Medical Costs

Abstract

Background

Metabolic syndrome (MetS) is a well-known comorbidity of chronic obstructive pulmonary disease (COPD). However, their interrelationship, particularly in early COPD, remains unclear. Therefore, we aimed to assess the prevalence and clinical characteristics of MetS in patients with early COPD, and to explore the impact of MetS on the frequency of COPD exacerbations and associated medical costs.

Patients and methods

We retrospectively enrolled 43,874 subjects from the KNHANES, including 2164 patients with early COPD (≥40 years old), recorded smoking history, and Global Initiative for Chronic Obstructive Lung Disease spirometric grade I or II, with data linked to the NHI database. We extracted and analyzed data regarding health-care utilization and medical costs for 5 years (2007 to 2012).

Results

Among 2164 patients with early COPD, the prevalence of MetS was 31.2%, and it was higher in women than in men (35.1% vs. 26.6%; P<0.001). Patients with MetS were older and had lower pulmonary function and greater number of comorbidities. The frequency of moderate-to-severe COPD exacerbations for 5 years was significantly higher in women with MetS than in those without MetS (5.8/year vs. 4.9/year; P=0.02). After adjusting for confounding factors, the risk for moderate-to-severe exacerbation was significantly greater in women with MetS (IRR, 1.17; 95% CI, 1.01 to 1.36; P=0.03). COPD exacerbations leading to hospitalization and medical expenses were also higher in women with MetS than in those without MetS.

Conclusion

MetS is more prevalent in women with early COPD. MetS increased the frequency of exacerbations and the medical costs in women with early COPD.

Keywords:

• COPD exacerbation
• metabolic syndrome

Acknowledgment

We thank Editage for editing a draft of this manuscript.

Abbreviations

BMI, body mass index; CHF, congestive heart failure; CIs, confidence intervals; COPD, chronic obstructive pulmonary disease; CVD, cardiovascular disease; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; GERD, gastroesophageal reflux disease; GOLD, Global Initiative for Chronic Obstructive Lung Disease HDL-C, high-density lipoprotein cholesterol; IHD, ischemic heart disease; IRRs, incidence rate ratios; KNHANES, Korean National Health and Nutrition Examination Survey; KOSSO, Korean Society for the Study of Obesity; MetS, metabolic syndrome; NHI, National Health Insurance; PVD, peripheral vascular disease; TG, triglyceride.

Ethics Statement

All KNHANES participants signed an informed consent form. Thus, ethical approval was not required, because our study used data from those surveys retrospectively.

Disclosure

The authors report no conflicts of interest in this work.