The weighty issue of obesity in paediatric respiratory medicine

Association of body anthropometry and obstructive sleep apnea in children: Variations observed in Hispanic children

Objectives

Obesity is a risk factor for obstructive sleep apnea (OSA) in children. Childhood obesity rates vary amongst different ethnic groups. Here the interaction of Hispanic ethnicity and obesity on OSA risk was evaluated.

Methods

Retrospective cross-sectional analysis of consecutive children undergoing polysomnography and anthropometry using bioelectrical impedance from 2017 to 2020. Demographics obtained from the medical chart. Children who had also undergone cardiometabolic testing were identified and the relationship of cardiometabolic markers with OSA and anthropometry was assessed.

Results

Data from 1217 children revealed Hispanic children were more likely to have moderate-severe OSA (36.0%) compared to Non-Hispanic children (26.5%), p < 0.001. Hispanic children had greater Body mass index (BMI), BMI percentile and percent body fat, p < 0.0001. In children that underwent cardiometabolic testing, Hispanic children had significantly greater serum alanine aminotransferase levels (ALT) levels. Following adjustment of age and sex, Hispanic ethnicity was not found to moderate the association of anthropometry with OSA, anthropometry with cardiometabolic markers, and OSA with cardiometabolic markers.

Conclusions

OSA was more likely in Hispanic children; this relationship was likely driven by obesity status rather than ethnicity. Among children undergoing cardiometabolic testing, Hispanic children were observed to have greater ALT concentrations however ethnicity did not impact the association of anthropometry and ALT or other cardiometabolic markers.

Effect of Threshold Inspiratory Muscle Training on Functional Fitness and Respiratory Muscle Strength Compared to Incentive Spirometry in Children and Adolescents With Obesity: A Randomized Controlled Trial

BACKGROUND

To determine the effect of threshold inspiratory muscle training (IMT) on functional fitness and respiratory muscle strength (RMS) compared to incentive spirometry (IS) in children/adolescents with obesity.

METHODS

A total of 60 obese children/adolescents aged 8-15 years were randomized into the threshold IMT group (n = 20), the IS group (n = 20), or the control group (n = 20). The IMT group performed 30 inspiratory breaths with the intensity set at 40% of baseline maximal inspiratory pressure (MIP) twice daily for 8 weeks; the IS group performed 30 breaths with sustained maximum inspiration twice daily for 8 weeks; and, the control group was assigned no training device for 8 weeks. Six-min walk test (6-MWT), RMS, and spirometry were compared between baseline and 8 weeks.

RESULTS

Six-MWT distance (528.5 ± 36.2 vs. 561.5 ± 35.2 m, p = 0.002) and MIP (121.2 ± 26.8 vs. 135.3 ± 32.1%Predicted, p = 0.03) were significantly improved after 8 weeks of IMT training. There was no significant difference in any evaluated pulmonary function parameters between baseline and 8 weeks in the IS or control groups; however, 6-MWT distance demonstrated a trend toward significant improvement in the IS group (526.9 ± 59.1 vs.549.0 ± 50.6 m, p = 0.10). No significant difference among groups was found for any variable relative to change from baseline to post-training.

CONCLUSION

Eight weeks of threshold IMT training significantly improved both inspiratory muscle strength (MIP) and functional fitness (6-MWT) in children/adolescents with obesity. Eight weeks of IS training yielded a trend toward significantly improved functional fitness.

Cardiorespiratory burden of brass neck coils placed on Kayan Karen long-neck women of Thailand

There is only scarce information regarding the physiological and health impact of lifelong wearing of the neck brass coils in Karen Kayan women. The purpose of this study was to determine the influence of wearing brass neck coils on cardiorespiratory and cerebrovascular functions in long-neck Karen women. A total of 28 Karen women (aged 23-66 years) were studied. Fourteen Karen women who had been wearing neck brass coils were compared with 14 Karen women with no neck coils. We also studied 14 age-matched city-living controls. Radiographic examination of 2 older Karen women wearing neck coils showed low levels of the clavicles. There were no group differences in resting heart rate and brachial-ankle pulse wave velocity. Both systolic and diastolic blood pressure was greater and functional capacity was lower in both Karen women than city-living controls (all p < 0.05). Karen women wearing neck coils demonstrated lower flow-mediated dilation, lung functions, including forced vital capacity and forced expiratory volume during the first second, and cerebral blood flow velocity than Karen women without neck coils (all p < 0.05). Karen women wearing neck coils demonstrate reduced endothelial and pulmonary functions as well as cerebral perfusion compared with age-matched Karen women without neck coils living in the same villages. Brass neck coils worn by Karen women may elevate risks of developing cardiopulmonary and cerebrovascular diseases. Novelty Cerebral blood flow velocity and macrovascular and microvascular functions were lower in Karen wearing neck coils. There appears to be substantial burden of brass neck coils exerted on physiological systems in Karen women.

Exercise-Induced Dyspnea in Children and Adolescents: Differential Diagnosis

Exercise-induced dyspnea in children and adolescents can occur for many reasons. Although asthma is the common cause, failure to prevent exercise-induced asthma by pretreatment with a bronchodilator, such as albuterol, indicates that other etiologies should be considered. Other causes of exercise-induced dyspnea include exercise-induced vocal cord dysfunction, exercise-induced laryngomalacia, exercise-induced hyperventilation, chest wall restrictive abnormalities, cardiac causes, and normal physiologic limitation. When exercise-induced dyspnea is not from asthma, cardiopulmonary exercise testing with reproduction of the patient's dyspnea is the means to identify the other causes. Cardiopulmonary exercise testing monitors oxygen use, carbon-dioxide production, end-tidal pCO₂ (partial pressure of carbon dioxide), and electrocardiogram. Additional components to testing are measurement of blood pH and pCO₂ when symptoms are reproduced, and selective flexible laryngoscopy when upper airway obstruction is observed to specifically identify vocal cord dysfunction or laryngomalacia. This approach is a highly effective means to identify exercise-induced dyspnea that is not caused by asthma. [Pediatr Ann. 2019;48(3):e121-e127.].

Maternal high fat diet compromises survival and modulates lung development of offspring, and impairs lung function of dams (female mice)

Background

Epidemiological studies have identified strong relationships between maternal obesity and offspring respiratory dysfunction; however, the causal direction is not known. We tested whether maternal obesity alters respiratory function of offspring in early life.

Methods

Female C57Bl/6 J mice were fed a high or low fat diet prior to and during two rounds of mating and resulting pregnancies with offspring lung function assessed at 2 weeks of age. The lung function of dams was measured at 33 weeks of age.

Results

A high fat diet caused significant weight gain prior to conception with dams exhibiting elevated fasting glucose, and glucose intolerance. The number of surviving litters was significantly less for dams fed a high fat diet, and surviving offspring weighed more, were longer and had larger lung volumes than those born to dams fed a low fat diet. The larger lung volumes significantly correlated in a linear fashion with body length. Pups born from the second pregnancy had reduced tissue elastance compared to pups born from the first pregnancy, regardless of the dam’s diet. As there was reduced offspring survival born to dams fed a high fat diet, the statistical power of lung function measures of offspring was limited. There were signs of increased inflammation in the bronchoalveolar lavage fluid of dams (but not offspring) fed a high fat diet, with more tumour necrosis factor-α, interleukin(IL)-5, IL-33 and leptin detected. Dams that were fed a high fat diet and became pregnant twice had reduced fasting glucose immediately prior to the second mating, and lower levels of IL-33 and leptin in bronchoalveolar lavage fluid.

Conclusions

While maternal high fat diet compromised litter survival, it also promoted somatic and lung growth (increased lung volume) in the offspring. Further studies are required to examine downstream effects of this enhanced lung volume on respiratory function in disease settings.