Clinical characteristics of the asthma-COPD overlap syndrome--a systematic review

TY - JOUR

T1 - Clinical characteristics of the asthma-COPD overlap syndrome--a systematic review

AU - Nielsen, Mia

AU - Bårnes, Camilla Boslev

AU - Ulrik, Charlotte Suppli

PY - 2015/7/27

Y1 - 2015/7/27

N2 - BACKGROUND AND OBJECTIVE: In recent years, the so-called asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) has received much attention, not least because elderly individuals may present characteristics suggesting a diagnosis of both asthma and COPD. At present, ACOS is described clinically as persistent airflow limitation combined with features of both asthma and COPD. The aim of this paper is, therefore, to review the currently available literature focusing on symptoms and clinical characteristics of patients regarded as having ACOS.METHODS: Based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, a systematic literature review was performed.RESULTS: A total of 11 studies met the inclusion criteria for the present review. All studies dealing with dyspnea (self-reported or assessed by the Medical Research Council dyspnea scale) reported more dyspnea among patients classified as having ACOS compared to the COPD and asthma groups. In line with this, ACOS patients have more concomitant wheezing and seem to have more cough and sputum production. Compared to COPD-only patients, the ACOS patients were found to have lower FEV1% predicted and FEV1/FVC ratio in spite of lower mean life-time tobacco exposure. Furthermore, studies have revealed that ACOS patients seem to have not only more frequent but also more severe exacerbations. Comorbidity, not least diabetes, has also been reported in a few studies, with a higher prevalence among ACOS patients. However, it should be acknowledged that only a limited number of studies have addressed the various comorbidities in patients with ACOS.CONCLUSION: The available studies indicate that ACOS patients may have more symptoms and a higher exacerbation rate than patients with asthma and COPD only, and by that, probably a higher overall respiratory-related morbidity. Similar to patients with COPD, ACOS patients seem to have a high occurrence of comorbidity, including diabetes. Further research into the ACOS, not least from well-defined prospective studies, is clearly needed.

AB - BACKGROUND AND OBJECTIVE: In recent years, the so-called asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) has received much attention, not least because elderly individuals may present characteristics suggesting a diagnosis of both asthma and COPD. At present, ACOS is described clinically as persistent airflow limitation combined with features of both asthma and COPD. The aim of this paper is, therefore, to review the currently available literature focusing on symptoms and clinical characteristics of patients regarded as having ACOS.METHODS: Based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, a systematic literature review was performed.RESULTS: A total of 11 studies met the inclusion criteria for the present review. All studies dealing with dyspnea (self-reported or assessed by the Medical Research Council dyspnea scale) reported more dyspnea among patients classified as having ACOS compared to the COPD and asthma groups. In line with this, ACOS patients have more concomitant wheezing and seem to have more cough and sputum production. Compared to COPD-only patients, the ACOS patients were found to have lower FEV1% predicted and FEV1/FVC ratio in spite of lower mean life-time tobacco exposure. Furthermore, studies have revealed that ACOS patients seem to have not only more frequent but also more severe exacerbations. Comorbidity, not least diabetes, has also been reported in a few studies, with a higher prevalence among ACOS patients. However, it should be acknowledged that only a limited number of studies have addressed the various comorbidities in patients with ACOS.CONCLUSION: The available studies indicate that ACOS patients may have more symptoms and a higher exacerbation rate than patients with asthma and COPD only, and by that, probably a higher overall respiratory-related morbidity. Similar to patients with COPD, ACOS patients seem to have a high occurrence of comorbidity, including diabetes. Further research into the ACOS, not least from well-defined prospective studies, is clearly needed.

KW - Adult

KW - Aged

KW - Aged, 80 and over

KW - Asthma

KW - Comorbidity

KW - Diabetes Mellitus

KW - Disease Progression

KW - Female

KW - Forced Expiratory Volume

KW - Humans

KW - Lung

KW - Male

KW - Middle Aged

KW - Prognosis

KW - Pulmonary Disease, Chronic Obstructive

KW - Risk Factors

KW - Syndrome

KW - Vital Capacity

KW - Young Adult

U2 - 10.2147/COPD.S85363

DO - 10.2147/COPD.S85363

M3 - Review

C2 - 26251584

SN - 1176-9106

VL - 10

SP - 1443

EP - 1454

JO - International Journal of COPD

JF - International Journal of COPD

IS - 1

ER -