Mechanical effects of obesity on central and peripheral airway resistance in nonasthmatic early pubescent children

Abstract

Background In children, obesity typically reduces functional residual capacity (FRC), which reduces airway caliber and increases airway resistance. Whether these obesity‐related changes in respiratory function can alter bronchodilator responsiveness is unknown. Objective To investigate bronchodilator responsiveness in nonasthmatic children with and without obesity. Methods Seventy nonasthmatic children, 8−12 years old, without (n = 19) and with (n = 51) obesity, completed spirometry, impulse oscillometry, and airway resistance measurements through plethysmography pre/post 360 µg of inhaled albuterol. FRC was assessed pre albuterol. A two‐way analysis of variance determined the effects of obesity (group) and inhaled albuterol (pre−post) on outcome measures. Results FRC (%total lung capacity) was 16% lower in children with obesity compared with those without obesity. There was no significant group by pre−post albuterol interaction on any outcome variables. Albuterol inhalation reduced total, central and peripheral airway resistance and increased airway reactance (i.e., less negative) to a similar degree in children with and without obesity. In children with obesity, airway resistance was increased whether measured by impulse oscillometry or plethysmography. However, once airway resistance was adjusted for lung volumes (i.e., specific airway resistance or sRaw), there were no differences between children with and without obesity. In addition, significant but moderate associations were detected between chest mass and FRC (r = −0.566; p < 0.001), FRC and total airway resistance (i.e., Raw; r = −0.445; p < 0.001). Conclusions In nonasthmatic early pubescent children, obesity increases total, central, and peripheral respiratory system resistance. However, the added respiratory system resistance and low lung volume breathing with obesity are not sufficient to reduce bronchodilator responsiveness.

Reduced exercise capacity for muscle mass in adolescents living with obesity

“…Lung function tended to be greater in AlwO. In a younger cohort of children, obesity did not affect spirometric values 31 . Of note, the current population had a lower BMI percentile compared to the study of younger children (mean 98.55 vs. 122.6), but a nonsignificant greater z ‐score (mean 2.33 vs. 2.18).…”

“…From the scan, total body mass, lean body mass, total fat mass, and lean leg mass (LLM) were extracted. As done by others, 31 chest mass and fat mass, and abdominal mass and fat mass, were also derived.…”

Reduced exercise capacity for muscle mass in adolescents living with obesity

“…From the scan, total body mass, lean body mass, total fat mass, and LLM were extracted. As done by others (23), chest mass and fat mass, and abdominal mass and fat mass, were also derived.…”

Respiratory Muscle Interval Training Improves Exercise Capacity in Obese Adolescents during a 3-Week In-Hospital Multidisciplinary Body Weight Reduction Program

“…Respiratory dysfunctions observed in patients with obesity are characterized by impaired breathing mechanics, decreased respiratory system compliance, increased small airway resistance, and by alterations in both breathing pattern and respiratory drive [1][2][3][4]. Such dysfunctions are already evident in children and adolescents who do not exhibit complications induced by the disease [5][6][7][8]. Overall, these alterations can cause increased work of breathing and O 2 cost of breathing [9,10] and increased metabolic requirements at rest and during exercise [11], and concur to determine exertional dyspnea and early respiratory muscle fatigue during exercise [12].…”