medwireNews: Analysis of a cohort of Japanese chronic obstructive pulmonary disease (COPD) patients with a low exacerbation frequency shows that low body mass index (BMI) and poor health-related quality of life (HRQoL) independently predict flare ups of the disease.
Masaharu Nishimura (Hokkaido University School of Medicine, Sapporo, Japan) and colleagues previously reported that the Hokkaido COPD cohort (N=268) had a remarkably low exacerbation frequency over 5-years of follow-up, which was not associated with forced expiratory volume in 1 second changes.
For the current study, the researchers used a number of definitions of exacerbation for which the frequency ranged from 0.06 per person/year when only hospitalizations were considered to 0.78 per person/year when patient-reported exacerbations were included.
HRQoL, according to the St George’s Respiratory Questionnaire (SGRQ), was consistently associated with exacerbations, including exacerbation-free survival, exacerbation frequency, and recurrent exacerbations. This was true whether exacerbations were defined by the presence of defined symptoms requiring a prescription change or hospital admission.
For example, every 4-point increase in SGRQ score (indicating a worsening of HRQoL) was associated with a 19% increase in the likelihood for shorter exacerbation-free survival during follow-up, when defined by hospitalization.
Additionally, in a multivariate model, for every unit increase in BMI, the likelihood for shorter exacerbation-free survival decreased by 14% when defined by hospital admission and by 7% when defined by prescription change; BMI was also significantly associated with exacerbation frequency by both definitions and recurrent exacerbations by the hospitalization definition.
Finally, for every 10-year increase in age, patients were 57% more likely to have recurrent exacerbations according to the hospitalization definition.
Reporting in the European Respiratory Journal, the authors note that only the Activity score of the SGRQ was significantly associated with exacerbations in all analyses, which the authors say may be due to the close correlation between this subscore and the dyspnea scale.
Nishimura and colleagues therefore conclude that “it would be very important to identify patients who have limited physical activities due to dyspnea or weight loss and perform a therapeutic intervention for such patients by medication, rehabilitation, and supporting nutrition in order to reduce the morbidity and mortality from COPD exacerbations.”
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By Kirsty Oswald, medwireNews Reporter