Are overweight asthmatics more difficult to control?

Abstract

The relationship between asthma and obesity appears to be quite complex. The aim of this study was to assess the effect of excess weight on asthma control evolution in a cohort of asthmatics. A prospective database was set up, which enrolled adult asthmatics with persistent (mild, moderate or severe) asthma. The control of asthma was defined as a binary variable, acceptable or unacceptable. In order to evaluate the effect of body mass index (BMI; <25 or > or =25), data were analysed using a continuous time homogeneous Markov model in which the forces ruling the transition between the two health states were estimated. The following confounding covariates were also evaluated in the model: severity of asthma, current treatment with oral corticosteroids (OCS) and history of OCS over the year preceding inclusion. About 406 asthmatics were included who made a total of 1639 consultations; the median length of follow up was 182 days. Using a univariate model, overweight patients had a lower risk of transiting from the unacceptable to the acceptable health state (RR = 0.45; P < 0.01). The effect of weight remained significant (RR = 0.53; P < 0.01) in the multivariate model including the other covariates. Moreover, transition probabilities stabilized more rapidly for patients with BMI < 25 (200 vs 300 days). In this study, we thus demonstrated that there is an association between excess weight and transition from unacceptable to acceptable control. Because control of asthma clearly drives asthma management, this finding has consequences for defining original new strategies for managing asthma in overweight patients.

Obesity, Nutrition, and Asthma in Children

“…Data suggest that obese asthmatics are at least as hard to control as their lean counterparts, and in some adult reports, are less responsive to conventional therapies. 101,102,114,[116][117][118][119][120] Evidence suggests that this reduced treatment efficacy may be rooted in true glucocorticosteroid resistance. 116 Recently, Forno et al showed that obese children may also be less responsive to inhaled corticosteroids.…”

Asthma-related comorbidities

“…Obese patients seem to present a specific asthma phenotype, associated with low lung volumes breathing, a less eosinophilic inflammatory process and a reduced response to asthma medications [90,[94][95][96]. It has been suggested that obese asthmatic patients have an altered response to asthma medications, particularly a reduced response to inhaled corticosteroids [96,97].…”

Control and severity: complementary approaches to asthma management

“…Then, medico-economic models (e.g. Markov model) can be built to analyse how these factors influence healthcare costs (14,20). Such modelling is particularly useful to define treatment targets from both an economic and clinical point of view.…”

“…As a consequence of the above-mentioned differences, determinants and clinical correlates of control and severity may not be identical: for instance, body mass index and obesity are associated with control and quality of life but not with severity (13,14); conversely, tobacco smoking is associated with both poorer control and increased severity (15,16), although this relationship was not significant in the study by Sullivan et al (2). In addition, for patients with a N. Roche 1 , P. Godard given level of severity, control is an additional contributor to quality of life (17).…”