Biomaterial Database

Hyperventilation during exercise: independence on exercise-induced bronchoconstriction in mild asthma. 1996

V L Kinnula, and A R Sovijärvi

Department of Medicine, Helsinki University Central Hospital, Finland.

Ventilatory gas exchange during exercise was compared in patients with mild asthma (11 females and 11 males), hyperventilation syndrome (HVS, 11 females), and healthy subjects (11 females and 11 males) in order to assess hyperventilation during exercise and its association with exercise-induced bronchoconstriction. The asthmatics showed decreased working capacity and decreased maximal oxygen consumption, with no evidence of limitation due to impairment of ventilatory capacity. Ventilatory equivalents for CO2 and O2 (VE/VCO2 and VE/VO2) at rest did not differ between the controls and asthmatics, but they were significantly elevated in HVS. In female asthmatics, ventilatory equivalents during exercise were significantly (P < 0.05) elevated compared with those of healthy subjects; in female controls, VE/VCO2 was 30.1 +/- 3.3 at low exercise and 27.4 +/- 6.5 at maximal exercise. In female asthmatics, the corresponding figures were 34.9 +/- 6.1 and 36.7 +/- 5.3. Furthermore, VE/VCO2 individually related to percent of maximal oxygen consumption (VO2max) was significantly increased in female asthmatics both at low and high VO2. The highest ventilatory equivalents were obtained in HVS, 41.7 +/- 6.7 and 43.9 +/- 0.9, respectively. Significant exercise-induced bronchoconstriction (decrease of FEV1 > 15%) was found in 50% of the asthmatics. The ventilatory equivalents did not correlate with exercise-induced changes in FEV1 (r2 < 0.3). Mild exercise-induced hyperventilation which was observed in mild female asthmatics, did not appear to be related to exercise-induced bronchoconstriction.

UI	MeSH Term	Description	Entries
D006985	Hyperventilation	A pulmonary ventilation rate faster than is metabolically necessary for the exchange of gases. It is the result of an increased frequency of breathing, an increased tidal volume, or a combination of both. It causes an excess intake of oxygen and the blowing off of carbon dioxide.	Hyperventilations
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D008297	Male		Males
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D011659	Pulmonary Gas Exchange	The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER.	Exchange, Pulmonary Gas,Gas Exchange, Pulmonary
D005260	Female		Females
D005541	Forced Expiratory Volume	Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.	Forced Vital Capacity, Timed,Timed Vital Capacity,Vital Capacity, Timed,FEVt,Capacities, Timed Vital,Capacity, Timed Vital,Expiratory Volume, Forced,Expiratory Volumes, Forced,Forced Expiratory Volumes,Timed Vital Capacities,Vital Capacities, Timed,Volume, Forced Expiratory,Volumes, Forced Expiratory
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D001250	Asthma, Exercise-Induced	Asthma attacks following a period of exercise. Usually the induced attack is short-lived and regresses spontaneously. The magnitude of postexertional airway obstruction is strongly influenced by the environment in which exercise is performed (i.e. inhalation of cold air during physical exertion markedly augments the severity of the airway obstruction; conversely, warm humid air blunts or abolishes it).	Bronchospasm, Exercise-Induced,Exercise-Induced Asthma,Exercise-Induced Bronchospasm,Asthma, Exercise Induced,Bronchospasm, Exercise Induced,Exercise Induced Asthma,Exercise Induced Bronchospasm,Exercise-Induced Asthmas,Exercise-Induced Bronchospasms