Effect of Regular Use of High-dose Nebulized β2-Agonists on Resting Energy Expenditure, Weight, and Handgrip Strength in Patients With Chronic Airflow Limitation

A proportion of patients with COPD and chronic asthma have a raised resting energy expenditure (REE), both when compared with values given by prediction equations and when compared with matched control subjects. The mechanism of this is not known. This elevated REE has been proposed as a possible cause of the weight loss seen in a proportion of patients. Inhaled β₂-agonists increase oxygen consumption (Vo₂) in the short term, although Wilson et al have also shown that tolerance to this effect occurs within 8 weeks. However, a sustained rise in REE of 7.8% in healthy young men receiving oral terbutaline for 2 weeks has been observed. Slow-release oral salbutamol has been shown to increase muscle strength over 2 weeks in healthy control subjects. Many patients with chronic severe airflow obstruction are taking high doses of β₂-agonists at least four times a day via a nebulizer and the aim of this prospective study was to see if their use of regular high-dose nebulized salbutamol altered REE, body composition, or handgrip strength (HGS). canadian health and care mall

Materials and Methods
Subjects and Study Design
We recruited 20 consecutive respiratory outpatients with chronic airflow limitation (CAL) of mixed etiology who were referred by their physician for a formal assessment for home nebulizer therapy as part of their clinical care. The primary diagnosis was either tobacco-related COPD (n=17) or chronic asthma (n=3). Breathlessness due to obstructive lung disease had been present for at least 2 years and the patients had remained symptomatic despite optimization of therapy, including inhaled bronchodilator drugs by metered dose inhaler (MDI), inhaled steroids, and oral theophyllines, plus the treatment of any associated disorder. Compliance with MDI therapy was checked in clinic before the study with regard to inhaled technique and a verbal assessment of frequency of dosing.

Category: Airflow Limitation

Tags: chronic airflow limitation, resting energy expenditure