Neonatal rhinorrhea, heart rate variability, and childhood exercise-induced wheeze

Background

There is increasing evidence linking infant rhinorrhea to school-age exercise-induced wheeze (EIW) via a parasympathetic nervous system pathway. The ratio of the root mean square of successive differences in heart beats (RMSSD) measured in quiet sleep versus active sleep (RMSSDQS:AS) is a novel biomarker in asthma.

Objective

We tested the hypotheses that (1) neonatal rhinorrhea predicts childhood EIW independent of other neonatal respiratory symptoms, (2) neonatal RMSSDQS:AS predicts childhood EIW, and (3) RMSSDQS:AS mediates the association between neonatal rhinorrhea and childhood EIW.

Methods

Participants from the Safe Passage/Environmental Influences on Child Health Outcomes (PASS/ECHO) prospective birth cohort had heart rate variability extracted from electrocardiogram traces acquired in the first month of life. Parents reported on rhinorrhea in their child at age 1 month and on EIW in their child at ages 4 to 11 years.

Results

In models (N = 831) adjusted for potential confounders and covariates, including neonatal wheeze, cough and fever, neonatal rhinorrhea-predicted childhood EIW (relative risk [RR] = 2.22; P = .040), specifically, among females (RR = 3.38; P = .018) but not males (RR = 1.39; P = .61). Among participants contributing data in both active and quiet sleep (n = 231), RMSSDQS:AS predicted EIW (RR = 2.36; P = .003) and mediated the effect estimate of neonatal rhinorrhea predicting EIW among females. Half of the females with a higher RMSSDQS:AS and neonatal rhinorrhea (n = 5 of 10) developed EIW as compared with 1.8% of the other females (n = 2 of 109) (P < .001).

Conclusions

Our findings support dysregulation of the parasympathetic nervous system in infancy as one of the possible underlying mechanisms for the development of EIW later in childhood among females, which could aid in the development of future interventions.

Case report: Open water swimming as a possible treatment for asthma

Asthma is a complex medical problem for which currently available treatment can be incompletely effective. This case report describes a 49 year old woman who had suffered from asthma since her teenage years that resolved after she took up regular open water swimming. After sharing this case report with an international open water swimming community on social media, over one hundred people with asthma commented that their symptoms had also improved after taking up this activity. The mechanism whereby open water swimming might alleviate asthma has not been established. Possibilities include benefits to mental health, anti-inflammatory effects, being more fit, improved immune function and suppression of the bronchoconstrictive component of the diving reflex. Further research might usefully confirm or refute these clinical observations.

Self-Contained Underwater Breathing Apparatus (SCUBA) Diving and Asthma: Where are we in 2023?

Asthma is a risk factor for an adverse event while diving utilizing self-contained breathing apparatus (SCUBA). There are various consensus based recommendations suggesting criteria to evaluate a person with asthma and allow safe SCUBA diving. A systematic review of the medical literature using Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) was published in 2016 and concluded there is limited evidence, but subjects with asthma are likely at increased risk of adverse if events if participating in SCUBA. This previous review also included there are insufficient data to inform the decision for a specific patient with asthma to dive. The search strategy used in 2016 was repeated in 2022 and is reported in this paper. The conclusions are the same. Suggestions for the clinician are provided to assist in the shared decision-making discussion related to an asthma patient's request to participate in recreational SCUBA diving.

Exercise-Induced Bronchoconstriction in Children

Exercise-induced bronchoconstriction (EIB) is a transient airflow obstruction, typically 5-15 min after physical activity. The pathophysiology of EIB is related to the thermal and osmotic changes of the bronchial mucosa, which cause the release of mediators and the development of bronchoconstriction in the airways. EIB in children often causes an important limitation to physical activities and sports. However, by taking appropriate precautions and through adequate pharmacological control of the condition, routine exercise is extremely safe in children. This review aims to raise awareness of EIB by proposing an update, based on the latest studies, on pathological mechanisms, diagnosis, and therapeutic approaches in children.

VO 2 Max Improvement of 96% in a Non-Elite Recreational Athlete over 24 Months

VO ₂ max is a measure of athletic performance and is generally considered an excellent health parameter for athletic performance testing. Various methods are used to generate such a result generally using a treadmill or cycle ergometer. Improvements have been shown through training. The upper limit of such improvement has been difficult to find in the literature in part because testing often starts with individuals already at a superior level of performance. As genetics may play a significant role in an individual's VO ₂ max, training can only contribute a portion of the result. Humans have a range of maximal oxygen utilization with upper limits approaching 100 mL/kg. This case report demonstrates a 96% improvement over time secondary to selective intense training. The intent was to document objectively amelioration of the VO ₂ max using a defined protocol on standardized testing equipment. This may lead to more efficient training of individuals desiring performance improvement.

Protective effect of a low single dose inhaled steroid against exercise induced bronchoconstriction

OBJECTIVE

Daily use of inhaled corticosteroids (ICS) reduces exercise induced bronchoconstriction (EIB) in asthmatic children. A high single dose of ICS also provided acute protection against EIB. Objective of this study is to investigate whether a low single dose of ICS offers protection against EIB in asthmatic children.

METHODS

31 Mild asthmatic children not currently treated with inhaled corticosteroids, 5-16 years, with EIB (fall in FEV0.5/1 ≥ 13%) were included in a prospective intervention study. They performed two ECT's within 2 weeks. Four hours before the second test children inhaled 200 μg beclomethasone-dipropionate (BDP) with a breath-actuated inhaler (BAI).

RESULTS

The median fall in FEV0.5/1 after 200 μg BDP was significantly reduced from 30.9% at baseline to 16.0% (P < 0.001). Twenty children (64.5%) showed a good response to 200 μg BDP (≥ 50% decrease in fall of FEV0.5/1), while 8 children showed a moderate response (25-50%), and three children showed no response at all (< 25%).

CONCLUSION

A low single dose ICS offers acute protection against EIB in the majority of asthmatic children not currently treated with inhaled corticosteroids.