Abstract
Background: Assessment and evaluation of the strength of the respiratory muscles are beneficial in some clinical conditions, Rheumatoid arthritis is an articular disorder with extra-articular manifestations affecting other organs and tissues and worsening prognosis. Pulmonary system involved in about 30-40% of RA patients. The objective of this study is to assess respiratory muscles strength as a biomarker of lung function among asymptomatic patients with rheumatoid arthritis. Patients and Methods: It was analytical, facility-based study at pulmonary function test lab, department of respiratory care at King Saud Medical City (KSMC). Patients confirmed with rheumatoid arthritis, according to ACR /EULAR were selected with age group 18-75 years-old. Pulmonary function tests were carried out using MasterScreen PFT spirometer (CareFusion, Hoechberg Germany manufacture). The machine was calibrated daily.We used of the MicroGard (R) mouthpieces containing filter to prevent the infections. Result: A total of 70 participants in the age range 18-75 years enrolled in the study. Out of 70 participants, 14.3% of the study participants were male subjects while 85.7%were female subjects. Saudis constituted 88.6% of the participants were Saudis and 12.4% non-Saudis. The distribution of the chronicity of rheumatoid arthritis showed 60% of the participants developed rheumatoid arthritis within five years, or less. Mean values of maximal voluntary ventilation (MVV) was significantly lower than in the participants actual measures compared with the mean of predicted values. The mean values of both maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were significantly lower than in participants' actual measures and predicted values. There was significant statistical relation between the maximal voluntary ventilation (MVV) and maximal expiratory pressure (MEP), maximal inspiratory pressure (MIP) of the participants. Conclusion: Maximum voluntary ventilation (MVV), maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) are essential parameters to evaluate the respiratory muscles strength among patients with rheumatoid arthritis. We may be recommended to be to perform these tests done routinely as a part of airflow category of pulmonary function testing for those patients as there are no adverse effects, non-invasive and relatively easy to perform manoeuvres.