title: Vitamin D deficiency and exercise-induced laryngospasm in young competitive rowers.
abstract: Exercise-induced dyspnea is common among adolescents and young adults and often originates from exercise-induced bronchoconstriction (EIB). Sometimes, dyspnea corresponds to exercise-induced laryngospasm (EILO), which is a paradoxical decrease in supraglottic/glottic area. Vitamin D deficiency, which occurs frequently at northern latitudes, might favor laryngospasm by impairing calcium transport and slowing striate muscle relaxation. The aim of this study was to evaluate whether vitamin D status has an influence on bronchial and laryngeal responses to exercise in young, healthy athletes. EIB and EILO were investigated during winter in 37 healthy competitive rowers (24 males; age range 13-25 years), using the eucapnic voluntary hyperventilation test (EVH). EIB was diagnosed when forced expiratory volume in the first second decreased by 10%, EILO when maximum mid-inspiratory flow (MIF50) decreased by 20%. Most athletes (86.5%) had vitamin D deficiency (below 30 ng/mL), 29 mild-moderate (78.4%) and 3 severe (8.1%). EVH showed EIB in 10 subjects (27%), EILO in 16 (43.2%), and combined EIB and EILO in 6 (16.2%). Athletes with EILO had lower vitamin D (19.1 ng/mL vs. 27.0 ng/mL, p < 0.001) and higher parathyroid hormone (30.5 pg/mL vs. 19.2 pg/mL, p = 0.006) levels. The degree of laryngoconstriction (post-EVH MIF50 as a percentage of pre-EVH MIF50) was related directly with vitamin D levels (r = 0.51; p = 0.001) and inversely with parathyroid hormone levels (r = -0.53; p = 0.001). We conclude that vitamin D deficiency is common during winter in young athletes living above the 40th parallel north and favors laryngospasm during exercise, probably by disturbing calcium homeostasis. This effect may negatively influence athletic performance.
authors.affiliation: a Respiratory Medicine and Allergy, AOU "Policlinico-Vittorio Emanuele", Department of Clinical and Experimental Medicine, University of Catania, Via Santa Sofia 78, 95123 Catania, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Heffler
authors.affiliation: b Department of Public Health and Infectious Diseases, "Sapienza" University of Rome, Piazzale Aldo Moro 5, 00185 Roma, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Bonini
authors.affiliation: c Department of Medical Sciences, University of Torino, Via Genova 3, 10126 Torino, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Brussino
authors.affiliation: d Department of Pneumology, Città della Salute e della Scienza, Via Genova 3, 10126 Torino, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Solidoro
authors.affiliation: c Department of Medical Sciences, University of Torino, Via Genova 3, 10126 Torino, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Guida
authors.affiliation: c Department of Medical Sciences, University of Torino, Via Genova 3, 10126 Torino, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Boita
authors.affiliation: a Respiratory Medicine and Allergy, AOU "Policlinico-Vittorio Emanuele", Department of Clinical and Experimental Medicine, University of Catania, Via Santa Sofia 78, 95123 Catania, Italy.
authors.forename: Giuliana
authors.initials: G
authors.lastname: Nicolosi
authors.affiliation: c Department of Medical Sciences, University of Torino, Via Genova 3, 10126 Torino, Italy.|d Department of Pneumology, Città della Salute e della Scienza, Via Genova 3, 10126 Torino, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Bucca
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D054874:Athletic Performance; D001982:Bronchial Diseases / Q000097:blood / Q000209:etiology; D002118:Calcium / Q000097:blood; D003251:Constriction, Pathologic / Q000097:blood / Q000209:etiology; D015444:Exercise; D005260:Female; D005541:Forced Expiratory Volume; D006706:Homeostasis; D006801:Humans; D006985:Hyperventilation / Q000097:blood; D007826:Laryngismus / Q000097:blood* / Q000209:etiology; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D014807:Vitamin D / Q000008:administration & dosage / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000150:complications; D055815:Young Adult
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; D002118:Calcium
keywords: asthma; asthme; cholecalciferol; cholécalciférol; eucapnic hyperventilation; exercice physique; exercise; hyperventilation normocapnique; laryngospasm; laryngospasme; rameurs; rowers