Tidal breath in healthy term newborns: An analysis from the 2nd to the 30th days of life

Beyond the Skin: Reduced Lung Function Associated With Atopic Dermatitis in Infants

BACKGROUND

Very few studies have examined lung function parameters using tidal breath analysis (TBA) in atopic dermatitis (AD) with its high potential for progression to asthma.

OBJECTIVE

To measure lung functions using TBA in infants with AD and in healthy controls (HCs), and to investigate the effects of disease severity, food sensitivity, and history of recurrent wheezing on TBA parameters in infants with AD.

METHODS

Two hundred thirty infants were included in this prospective cross-sectional study, including an AD group (n = 150) and an HC group (n = 80). Food sensitivity was assessed by means of food-specific IgE or the skin prick test. The severity of the disease was evaluated using the SCORing Atopic Dermatitis. Lung function was assessed using TBA.

RESULTS

The following TBA parameters were significantly lower in the AD group than in the HC group (P < .05): time to peak tidal expiratory flow, exhaled volume to peak tidal expiratory flow, ratio of time to peak tidal expiratory flow to expiratory time, ratio of exhaled volume to peak tidal expiratory flow to total expiratory volume, expiratory flow when 25% of tidal volume remains in the lungs, respiratory rate, and minute ventilation. No difference was observed in the AD group when TBA parameters were compared according to disease severity, food sensitivity, and history of recurrent wheezing (P > .05). The receiver-operating characteristic curve demonstrated by the ratio of time to peak tidal expiratory flow to expiratory time yielded an area under the curve of 0.826 (CI, 0.772-0.879), with a cutoff value of 31.65 or higher in differentiating AD, with a sensitivity of 78.7% and a specificity of 77.5%.

CONCLUSIONS

TBA curves can be a useful tool for demonstrating expiratory airway obstruction in AD and for providing objective information for the clinician. Bronchial obstruction was detected in young children with AD irrespective of the severity of the disease, food sensitivity, and history of recurrent wheezing.

From neonatal lung function to lung function and respiratory morbidity at 6-year follow-up

BACKGROUND

Lung function is traceable from infancy to adulthood. Only a few studies have examined lung function from birth to childhood longitudinally in children born moderate to late preterm. We aimed to investigate how prematurity and lung function in the neonatal period are related to lung function and respiratory morbidity at age 6 in former moderate to late preterm children compared with children born at term.

METHODS

Lung function was measured in a cohort of moderately to late preterm (n = 48) and term-born (n = 53) infants in the neonatal period by FeNO, and tidal breathing flow-volume loops (TBFVL) and at age 6 (n = 52) by spirometry, whole-body plethysmograph and impulse oscillation combined with a respiratory symptom questionnaire.

RESULTS

Moderate to late preterm children had a higher T_PEF /T_E ratio neonatally (42.6% vs. 33.7%, p = 0.02) and a lower % predicted orced expiratory volume in the first second at age 6 (94.4% vs. 101.9%, p = 0.01) compared to term-born children. We found a significant association between the variability of neonatal tidal volume and effective airway resistance at age 6 (β = -0.34, p = 0.03). No association between neonatal FeNO or TBFVL and respiratory morbidity at 6-year follow-up was shown.

CONCLUSION

Children born moderate to late preterm had lower lung function at age 6 than term-born children. We did not find evidence for the use of neonatal tidal breathing parameters as a predictor for subsequent respiratory morbidity or lung function, however sample size was small.

Fetal thoracic circumference in mid-pregnancy and infant lung function

BACKGROUND AND AIM

Impaired lung function in early infancy is associated with later wheeze and asthma, while fetal thoracic circumference (TC) predicts severity of neonatal lung hypoplasia. Exploring fetal origins of lung function in infancy, we aimed to determine if fetal TC in mid-pregnancy was associated with infant lung function.

METHODS

From the prospective Scandinavian general population-based PreventADALL mother-child birth cohort, all 851 3-month-old infants with tidal flow-volume measurements in the awake state and ultrasound fetal size measures at 18 (min-max 16-22) weeks gestational age were included. Associations between fetal TC and time to peak tidal expiratory flow to expiratory time (t_PTEF /t_E ) were analyzed in linear regression models. To account for gestational age variation, we adjusted TC for simultaneously measured general fetal size, by head circumference (TC/HC), abdominal circumference (TC/AC), and femur length (TC/FL). Multivariable models were adjusted for maternal age, maternal asthma, pre-pregnancy body mass index, parity, nicotine exposure in utero, and infant sex.

RESULTS

The infants (47.8% girls) were born at mean (SD) gestational age of 40.2 (1.30) weeks. The mean (SD) t_PTEF /t_E  was 0.39 (0.08). The mean (SD) TC/HC was 0.75 (0.04), TC/AC 0.87 (0.04), and TC/FL 4.17 (0.26), respectively. Neither TC/HC nor TC/AC were associated with infant t_PTEF /t_E while a week inverse association was observed between TC/FL and t_PTEF /t_E  ( β ^ $\hat{\beta }$  = -0.03, 95% confidence interval [-0.05, -0.007], p = 0.01).

CONCLUSION

Mid-pregnancy fetal TC adjusted for fetal head or abdominal size was not associated with t_PTEF /t_E in healthy, awake 3-month-old infants, while a weak association was observed adjusting for fetal femur length.

Infant lung function and maternal physical activity in the first half of pregnancy

Background and aim

Physical activity (PA) in pregnancy is important for maternal and possibly offspring health. To study the early origins of lung function we aimed to determine whether PA in the first half of pregnancy is associated with lung function in healthy 3-month-old infants.

Methods

From the general population-based Preventing Atopic Dermatitis and Allergies in Children birth cohort recruiting infants antenatally in Norway and Sweden, all 812 infants (48.8% girls) with available tidal flow-volume measures in the awake state at 3 months of age and mid-pregnancy data on PA were included. PA was self-reported by the mothers and, based on intensity, we categorised them as active or inactive during pregnancy. Furthermore, we defined active mothers as fairly or highly active. The main outcome was a ratio of time to peak tidal expiratory flow to expiratory time (t PTEF/t E) <0.25. Associations were analysed by logistic regression, adjusting for maternal age, education, parity, pre-pregnancy body mass index, in utero nicotine exposure and parental atopy.

Results

The mean±sd t PTEF/t E was 0.391±0.08 and did not differ significantly according to maternal PA level in pregnancy. The 290 infants of inactive mothers had higher odds of having t PTEF/t E <0.25 compared to infants of all active mothers (OR 2.07, 95% CI 1.13-3.82; p=0.019) and compared to infants (n=224) of fairly active (OR 2.83, 95% CI 1.26-7.24; p=0.018) but not highly active mothers (n=298).

Conclusion

Based on self-reported maternal PA in the first half of pregnancy, 3-month-old infants of inactive compared to active mothers had higher odds of a low t PTEF/t E.

Neonatal nutritional risk and pulmonary function

INTRODUCTION

The neonatal period is a critical initial stage of postnatal lung development and maturation. This study aimed to investigate the effects of the nutritional status on pulmonary function in late preterm and full-term neonates.

METHODS

A total of 172 newborns were included in the study. Nutritional risk screening, weight measurement, assessment of albumin and caloric intake, and a pulmonary function examination were conducted on the 7th day after birth.

RESULTS

There was a significant correlation between the nutritional risk and changes in body weight. Tidal volume (VT), minute ventilation (MV), VT per kg body weight (VT/kg), and MV per kg body weight (MV/kg) in the low nutritional risk group were significantly higher than those in the medium nutritional risk group (all P < .05). Albumin and caloric intake in the low nutritional risk group were significantly higher than those in the medium nutritional risk group (both P < .01). VT, VT/kg, MV, and MV/kg in the weight loss group were lower than those in the no weight loss group (all P < .05).

CONCLUSIONS

Changes in neonatal weight mainly affect lung volume (VT, VT/kg, MV, and MV/kg), suggesting that an improvement in the neonatal nutritional status is important for the development of lung volume.