Metabolic origins of childhood asthma

Maternal high-fat diet alters lung development and function in the offspring

The effects of maternal obesity on lung development have been recognized, and speculation is that these diseases are not simply because of accelerated pulmonary decline with aging but with a failure to achieve optimal lung development during early life. These studies tested the hypothesis that maternal obesity alters signaling pathways during the course of lung development that may affect life-long pulmonary health. Adult female mice were fed 60% fat [high-fat diet (HFD)] or 10% fat [control diet (CD)] for 8 wk before mating and through weaning. Pup lung tissues were collected at postnatal days (PN) 7, 21, and 90 (after receiving HFD or CD as adults). At PN7, body weights from HFD were greater than CD but lung weight-to-body weight ratios were lower. In lung tissues, NFκB-mediated inflammation was greater in HFD pups at PN21 and phospho-/total STAT3, phospho-/total VEGF receptor 2, and total AKT protein levels were lower with maternal HFD and protein tyrosine phosphatase B1 levels were increased. Decreased platelet endothelial cell adhesion molecule levels were observed at PN21 and at PN90 in the pups exposed to maternal HFD. Morphometry indicated that the pups exposed to maternal or adult HFD had fewer alveoli, and the effect was additive. Decreases in pulmonary resistance, elastance, and compliance were observed because of adult HFD diet and decreases in airway resistance and increases in inspiratory capacity because of maternal HFD. In conclusion, maternal HFD disrupts signaling pathways in the early developing lung and may contribute to deficiencies in lung function and increased susceptibility in adults.

Impulse oscillometry and obesity in children

OBJECTIVE

To compare impulse oscillometry system parameters of normal-weight children with overweight and obese children.

METHOD

All participants were submitted to the evaluation of lung function (spirometry and impulse oscillometry) following the American Thoracic Society standards. The evaluation of respiratory mechanics was performed using the Jaeger™ MasterScreen™ Impulse Oscillometry System (Erich Jaeger, Germany), three tests were recorded, with acquisition for at least 20seconds.

RESULTS

The study included 81 children (30 in the control group, 21 in the overweight group, and 30 the in obesity group), matched for age and sex. Regarding spirometry data, obesity group showed higher numerical values in relation to the control group; however, there were no significant differences among the three groups. For impulse oscillometry parameters, there was a difference between control group and obesity group for respiratory impedance (p=0.036), resistance at 5hertz (p=0.026), resonant frequency (p=0.029), and reactance area (p=0.014). For the parameters expressed in percentage of predicted, there were differences in resistance at 5 hertz, resonant frequency, and reactance area between control group and obesity group.

CONCLUSIONS

Obese children showed increased oscillometry parameters values representative of airway obstruction, compared to normal-weight children. Changes in some oscillometry parameters can already be observed in overweight school-aged children.