Obesity might be a good prognosis factor for COPD patients using domiciliary noninvasive mechanical ventilation

Abstract

Cachexia is known to be a deteriorating factor for survival of patients with chronic obstructive pulmonary disease (COPD), but data related to obesity are limited. We observed that obese patients with COPD prescribed long-term noninvasive mechanical ventilation (NIMV) had better survival rate compared to nonobese patients. Therefore, we conducted a retrospective observational cohort study. Archives of Thoracic Diseases Training Hospital were sought between 2008 and 2013. All the subjects were prescribed domiciliary NIMV for chronic respiratory failure secondary to COPD. Subjects were grouped according to their body mass index (BMI). The first group consisted of subjects with BMI between 20 and 30 kg/m 2 , and the second group consisted of subjects with BMI >30 kg/m 2 . Data obtained at the first month’s visit for the following parameters were recorded: age, sex, comorbid diseases, smoking history, pulmonary function test, 6-minute walk test (6-MWT), and arterial blood gas analysis. Hospital admissions were recorded before and after the domiciliary NIMV usage. Mortality rate was searched from the electronic database. Overall, 118 subjects were enrolled. Thirty-eight subjects had BMI between 20 and 30 kg/m 2 , while 80 subjects had BMI >30 kg/m 2 . The mean age was 65.8±9.4 years, and 81% were male. The median follow-up time was 26 months and mortality rates were 32% and 34% for obese and nonobese subjects ( P =0.67). Improvement in 6-MWT was protective against mortality. In conclusion, survival of obese patients with COPD using domiciliary NIMV was found to be better than those of nonobese patients, and the improvement in 6-MWT in such patients was found to be related to a better survival.

Patterns of use, survival and prognostic factors in patients receiving home mechanical ventilation in Western Australia: A single centre historical cohort study

“…In PULM disease, we confirm previously described associations between improved survival and younger age 10 , 11 and obesity. 25 , 26 In COPD, cachexia is associated with systemic inflammation, adverse metabolic changes and reduced survival. 27 – 29 An unexpected new association of oxygen therapy and improved survival in the PULM group in our study probably reflects a Western Australian policy of prohibiting oxygen therapy prescription to current smokers.…”

The Impact of Diabetes Mellitus in Patients with Chronic Obstructive Pulmonary Disease (COPD) Hospitalization

“…In our data set, COPD hospitalizations with DM were relatively younger and might have a higher body mass index than the COPD patients with no diabetes. Several studies have shown that underweight patients had a higher mortality than COPD patients with normal BMI, whereas overweight and obese individuals were associated with lower mortality [ 38 , 39 , 40 , 41 , 42 ]. In our study, we found that obesity was more common in diabetic patients with complications, and they had lower odds of mortality.…”

Update: non-invasive ventilation in chronic obstructive pulmonary disease

“…The mechanism for this is unclear but is likely to be related to the obesity paradox observed in critical care patients (42,43). Although this was previously seen only in patients requiring invasive mechanical ventilation (44,45), it has now been demonstrated in patients who also require NIV (40).…”

“…Obesity appears to be a protective factor in this patient group. Patients receiving domiciliary NIV with a BMI >30 kg/m 2 had longer survival compared with those with a BMI 20-30 kg/m 2 (40,41). It is recognised that obstructive sleep apnoea (OSA) is a common feature in obese patients, and so this protective effect could be due to the effect of NIV of improving the OSA; however even with adjustment for OSA, obesity appeared to have a protective effect (41).…”