RESUMO
Respiratory muscle endurance is of interest in pulmonary, critical care and many other areas of medicine. The maximal voluntary ventilation [MVV] test is an objective dynamic method for measuring the working capacity of respiratory muscles. Therefore, we designed the present study to determine the effect imposed by diabetes mellitus on respiratory muscle endurance in Saudi diabetic patients. We conducted this study in the Department of Physiology, College of Medicine, King Khalid University Hospital and Diabetic Centre, King Abdul-Aziz University Hospital, Riyadh, Saudi Arabia during the year 2002-2004. In this study, we recruited 39 male diabetic patients and equal number of control subjects and all participants were non-smokers with age range of 23-71 years. The subjects were matched for age, height and weight. We determined the respiratory muscles endurance by a direct MVV test during inspiratory and expiratory phases of respiration by using a MP-100 student Bio Pac system and compared the results using a paired t-test. In inspiratory and expiratory phases of respiration, diabetic patients showed a significant reduction in the mean values of direct MVV test [p<0.001] relative to their matched controls. We conclude that in diabetic patients the respiratory muscles endurance is impaired by a decreased in MVV values. This decline in MVV further showed that the diabetic patients have a reduced inhaled and exhaled volumes during consecutive breaths