Diagnosis and management of nasal obstruction in the athlete. A narrative review by subgroup B of the IOC Consensus Group on "Acute Respiratory Illness in the Athlete"

TRPA1/M8 agonists upregulate ciliary beating through the pannexin-1 channel in the human nasal mucosa

BACKGROUND

Nasal breathing is important for maintaining physiological respiration. However, airflow in the nasal cavity has an inherent cooling effect and may suppress ciliary beating, an essential frontline defense in the airway. Nasal airflow is thought to be perceived by thermoreceptors for cool temperatures. We herein investigated the effect of the activation of thermosensitive transient receptor potentials (TRPs) for cool/cold temperatures on ciliary beating to search for a compensatory mechanism.

METHODS

Inferior turbinates were collected from patients with chronic hypertrophic rhinitis. Ex vivo ciliary beat frequency (CBF) and ATP release were measured using a high-speed digital video camera and by luciferin-luciferase assay, respectively. Intracellular Ca2+ ([Ca2+]i) imaging of isolated ciliated cells was performed using Fluo-8. The nasal mucosae were also subjected to fluorescence immunohistochemistry and real-time RT-PCR for TRPA1/TRPM8.

RESULTS

CBF was significantly increased by adding either cinnamaldehyde (TRPA1 agonist) or l-menthol (TRPM8 agonist). This increase was inhibited by pannexin-1 blockers, carbenoxolone and probenecid. Cinnamaldehyde and l-menthol also increased the ATP release from the nasal mucosa and [Ca2+]i of isolated ciliated cells. Immunohistochemistry detected TRPA1 and TRPM8 on the epithelial surface including the cilia and in the submucosal nasal glands. Existence of these receptors were confirmed at the transcriptional level by real-time RT-PCR.

CONCLUSIONS

These results indicate the stimulatory effect of the activation of TRPA1/TRPM8 on ciliary beating in the nasal mucosa, which would be advantageous to maintain airway mucosal defense against the fall of temperature under normal nasal breathing. This stimulatory effect is likely to be mediated by pannexin-1.

International Olympic Committee (IOC) consensus statement on acute respiratory illness in athletes part 2: non-infective acute respiratory illness

Acute respiratory illness (ARill) is common and threatens the health of athletes. ARill in athletes forms a significant component of the work of Sport and Exercise Medicine (SEM) clinicians. The aim of this consensus is to provide the SEM clinician with an overview and practical clinical approach to non-infective ARill in athletes. The International Olympic Committee (IOC) Medical and Scientific Committee appointed an international consensus group to review ARill in athletes. Key areas of ARill in athletes were originally identified and six subgroups of the IOC Consensus group established to review the following aspects: (1) epidemiology/risk factors for ARill, (2) infective ARill, (3) non-infective ARill, (4) acute asthma/exercise-induced bronchoconstriction and related conditions, (5) effects of ARill on exercise/sports performance, medical complications/return-to-sport (RTS) and (6) acute nasal/laryngeal obstruction presenting as ARill. Following several reviews conducted by subgroups, the sections of the consensus documents were allocated to 'core' members for drafting and internal review. An advanced draft of the consensus document was discussed during a meeting of the main consensus core group, and final edits were completed prior to submission of the manuscript. This document (part 2) of this consensus focuses on respiratory conditions causing non-infective ARill in athletes. These include non-inflammatory obstructive nasal, laryngeal, tracheal or bronchial conditions or non-infective inflammatory conditions of the respiratory epithelium that affect the upper and/or lower airways, frequently as a continuum. The following aspects of more common as well as lesser-known non-infective ARill in athletes are reviewed: epidemiology, risk factors, pathology/pathophysiology, clinical presentation and diagnosis, management, prevention, medical considerations and risks of illness during exercise, effects of illness on exercise/sports performance and RTS guidelines.

Clinical perspectives on nasopharyngeal morphology in humans

The nasopharynx is an integral component of the upper aerodigestive tract, whose morphologic features share an intimate relationship with a vast array of clinical, functional, and quality of life conditions related to contemporary humans. Its composite architecture and central location amidst the nasal cavity, pharyngotympanic tube, palate, and skull base bears implications for basic physiologic functions including breathing, vocalization, and alimentation. Over the course of evolution, morphological modifications of nasopharyngeal anatomy have occurred in genus Homo which serve to distinguish the human upper aerodigestive tract from that of other mammals. Understanding of these adaptive changes from both a comparative anatomy and clinical perspective offers insight into the unique blueprint which underpins many clinical pathologies currently encountered by anthropologists, scientists, and otorhinolaryngologists alike. This discussion intends to familiarize readers with the fundamental role that nasopharyngeal morphology plays in upper aerodigestive tract conditions, with consideration of its newfound clinical relevance in the era of the COVID-19 pandemic.

Exercise Related Respiratory Problems in the Young-Is It Exercise-Induced Bronchoconstriction or Laryngeal Obstruction?

Complaints of breathlessness during heavy exercise is common in children and adolescents, and represent expressions of a subjective feeling that may be difficult to verify and to link with specific diagnoses through objective tests. Exercise-induced asthma and exercise-induced laryngeal obstruction are two common medical causes of breathing difficulities in children and adolescents that can be challenging to distinguish between, based only on the complaints presented by patients. However, by applying a systematic clinical approach that includes rational use of tests, both conditions can usually be diagnosed reliably. In this invited mini-review, we suggest an approach we find feasible in our everyday clinical work.