Supine changes in lung function correlate with chronic respiratory failure in myotonic dystrophy patients.
Quality of life and prognosis of patients with myotonic dystrophy type 1 (MD1) often depend on the degree of lung function impairment. This study was designed to assess the respective prevalence of ventilatory restriction, hypoxaemia and hypercapnia in MD1 patients and to determine whether postural changes in lung function could contribute to the early diagnosis of poor respiratory outcome. Fifty-eight patients (42.6±12.9 years) with MD1 were prospectively evaluated from April 2008 to June 2010 to determine their supine and upright lung function and arterial blood gases. The prevalence of ventilatory restriction was 36% and increased with the severity of muscular disability (from 7.7% to 70.6%). The prevalence of hypoxaemia and hypercapnia was 37.9% and 25.9%, respectively. Multiple regression analysis showed that the supine fall in FEV1 was the only variable associated with ventilatory restriction, hypoxaemia and hypercapnia. Our data indicate that supine evaluation of lung function could be helpful to predict poor respiratory outcome, which is closely correlated with hypoxaemia and/or hypercapnia.
Department of Pulmonary Function Testing and Exercise Testing, CHU Nancy, Nancy F-54000, France; EA 3450 DevAH - Development, Adaptation and Disadvantage, Cardiorespiratory regulations and motor control, Université de Lorraine, F-54000, France. Electronic address: m.poussel@chu-nancy.fr.
Mathias
M
Poussel
Department of Internal Medicine and Orphan Diseases, CHU Nancy, Nancy F-54000, France; Reference Centre in Inherited Metabolism Diseases, CHU Nancy, Nancy F-54000, France.
Pierre
P
Kaminsky
Department of Pulmonary Function Testing and Exercise Testing, CHU Nancy, Nancy F-54000, France; EA 3450 DevAH - Development, Adaptation and Disadvantage, Cardiorespiratory regulations and motor control, Université de Lorraine, F-54000, France.
Pierre
P
Renaud
Department of Pulmonary Function Testing and Exercise Testing, CHU Nancy, Nancy F-54000, France; EA 3450 DevAH - Development, Adaptation and Disadvantage, Cardiorespiratory regulations and motor control, Université de Lorraine, F-54000, France.
Julien
J
Laroppe
Department of Internal Medicine and Orphan Diseases, CHU Nancy, Nancy F-54000, France; Reference Centre in Inherited Metabolism Diseases, CHU Nancy, Nancy F-54000, France.
Lelia
L
Pruna
Department of Pulmonary Function Testing and Exercise Testing, CHU Nancy, Nancy F-54000, France; EA 3450 DevAH - Development, Adaptation and Disadvantage, Cardiorespiratory regulations and motor control, Université de Lorraine, F-54000, France.
Bruno
B
Chenuel
D000328:Adult; D002908:Chronic Disease; D004185:Disability Evaluation; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000175:diagnosis / Q000503:physiopathology; D000860:Hypoxia / Q000175:diagnosis / Q000503:physiopathology; D016014:Linear Models; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000175:diagnosis* / Q000503:physiopathology*; D011187:Posture / Q000502:physiology; D011446:Prospective Studies; D012131:Respiratory Insufficiency / Q000175:diagnosis* / Q000503:physiopathology*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013147:Spirometry; D016683:Supine Position
Hypercapnia; Hypoxaemia; Lung function; Myotonic dystrophy; Ventilatory restriction