The Relationship Between Lung Function and Health-Related Quality of Life in Patients With Generalized Myasthenia Gravis

• Published in: Archivos de bronconeumología (English ed.) 2006-05, Vol.42 (5), p.218-224
• Main Authors: de Freitas Fregonezi, G.A., Regiane-Resqueti, V., Pradas, J., Vigil, L., Casan, P.
• Format: Article
• Language: eng ; spa
• Subjects: Aged; Calidad de vida relacionada con la salud (CVRS); Female; Función pulmonary; Health-related quality of life (HRQL); Humans; Lung function; Male; Maximal respiratory pressures; Miastenia gravis; Middle Aged; Myasthenia gravis; Myasthenia Gravis - physiopathology; Presiones respiratorias máximas; Quality of Life; Respiratory Function Tests
• ISSN: 1579-2129; 0300-2896; 1579-2129
• DOI: 10.1016/S1579-2129(06)60449-7

To study lung function abnormalities and health-related quality of life (HRQL) in a group of patients diagnosed with generalized myasthenia gravis, and to analyze the relationship between these 2 sets of variables. In a prospective study of 20 patients diagnosed with generalized myasthenia gravis, the following parameters were measured: spirometry, static lung volumes, breathing pattern, maximal respiratory pressures, and maximum voluntary ventilation. HRQL was assessed using the 36-item short form general health questionnaire (SF-36). The mean (SD) age of the patients was 64 (11) years. Patients were classified into 2 groups depending on whether they had IIa (12 patients) or IIb (8 patients) type disease. A small decrease in total lung capacity (86%) and slight reductions in maximal inspiratory pressure (88%) and maximum voluntary ventilation (63% in group IIb) were observed. The HRQL domains most affected were those related to physical activity and self-perceived health status in all groups, although women were more affected. The scores relating to vitality and physical activity were found to be significantly associated with forced vital capacity and lung volumes. Tidal volume was associated with maximal inspiratory and expiratory pressures, inspiratory capacity, and maximum voluntary ventilation. The respiratory rate to tidal volume ratio was inversely associated with the first three of these variables. A very slight restrictive pattern and a reduction in inspiratory muscle strength were observed. The HRQL domains most affected were those related to physical activity and the patients' self-perceived health status. The weakness of the respiratory muscles contributes to the abnormalities observed in lung function and to the deterioration of health-related quality of life. Estudiar las alteraciones de la función pulmonar y de la calidad de vida relacionada con la salud (CVRS), así como las relaciones entre ambas áreas, en un grupo de pacientes diagnosticados de miastenia gravis generalizada. Se ha realizado un estudio pros-pectivo en 20 pacientes diagnosticados de miastenia gravis generalizada. Se evaluaron la espirometría, los volúmenes pulmonares estáticos, el patrón respiratorio, las presiones respiratorias máximas y la ventilación voluntaria máxima. La CVRS se valoró con el cuestionario general de salud SF-36. La edad media (± desviación estándar) de los pacientes fue de 64 ± 11 años. Se clasificaron en IIa (12 pacientes) y IIb (8 pacientes). Se observ