The combination of exercise and diet improves asthma control in nonobese patients with asthma but does not affect airway hyperresponsiveness (AHR) or airway inflammation, according to a recent study published in the Journal of Allergy and Clinical Immunology in Practice.
Louise Lindhardt Toennesen, MD, of the Respiratory Research Unit, Department of Respiratory Medicine, Bispebjerg University Hospital, Copenhagen, Denmark, and colleagues conducted an 8-week intervention of either high-intensity interval training, a high protein/low glycemic index diet, or a combination of the 2 to determine the effects on asthma control and clinical outcomes in nonobese patients with asthma. They randomly assigned 149 patients to 1 of 4 groups: exercise, diet, exercise plus diet, or a control group.
The outcomes included changes in Asthma Control Questionnaire (ACQ) score, Asthma Quality of Life Questionnaire (AQLQ) score, inflammatory cell counts in induced sputum, forced expiratory volume in 1 second (FEV1), fractional exhaled nitric oxide, and AHR. A total of 125 patients completed the study.
For patients in the exercise plus diet group, the ACQ score decreased from 1.9 to 1.0 and the AQLQ score increased from 5.2 to 6.2, which was statistically significant when compared with changes that occurred in the control group (P <.05 and <.01, respectively). However, neither the exercise only nor the diet only groups experienced any significant improvement in either ACQ or AQLQ scores compared with the control group. None of the intervention groups had any significant changes in sputum cell counts, FEV1, fractional exhaled nitric oxide, or AHR compared with the control group.
One potential study limitation is the increased contact with trainers and dieticians that those participants in the intervention groups had compared with those in the control group. However, trainers and dieticians were told not to provide medical counseling or advice during the sessions.
These findings suggest that a high protein/low glycemic index diet combined with high-intensity interval training improves both asthma control and quality of life in nonobese patients with asthma.
Toennesen LL, Meteran H, Hostrup M, et al. Effects of exercise and diet in nonobese asthma patients — a randomized controlled trial [published online November 10, 2017]. J Allergy Clin Immunol Pract. doi:10.1016/j.jaip.2017.09.028