FVC, FEV₁ and FEV₁/ FVC % in Rheumatoid Arthritic Female and their Relationships with Duration of the Disease

Abstract

Background: Rheumatoid Arthritis (RA) is the most common inflammatory disorder mediated through
the immune system, affecting joints and various organs including lungs. Pulmonary dysfunction in
RA patients has been reported. Objective: To observe FVC, FEV₁ and FEV₁/ FVC % in female patients
of RA and their relationships with duration of the disease. Methods: This cross-sectional study was
carried out in the Department of Physiology, BSMMU, Dhaka, from January to December 2009 on 90
RA female patients of 30-50 years age (Group B). For comparison, 30 age and BMI matched apparently
healthy subjects (Group A) were also studied. According to the duration of disease, RA patients were
subdivided into B₁ (newly diagnosed), B₂ (3-5 years ) and B₃ (6-10 years ). They were selected from the
Out Patient Department of Physical Medicine of Bangabandhu Sheikh Mujib Medical University,
Dhaka. FVC, FEV₁ and FEV₁/FVC% of all the subjects were measured by a digital MicroDL spirometer.
Results were expressed as percent of predicted value. For statistical analysis One-Way ANOVA,
Unpaired Student's 't' test and Pearson's correlation coefficient test were performed, as required.
Results: The mean percentage of predicted values of these lung function parameters in the healthy
female subjects and newly diagnosed (B₁) RA patients were within normal ranges. The mean percentage
of predicted values of all the spirometric variables were significantly lower in the patients in B₃
compared to those in B₂ (FVC p<0.01, FEV₁ p<0.01), B₁ (FVC p<0.05, FEV₁ p<0.05, FEV₁/FVC% p<
0.001) and A (FVC p<0.01, FEV₁ p<0.001, FEV₁/FVC% p<0.001), except FEV₁/FVC% in B₃ vs B₂ which
was lower but nonsignificant. Again these same parameters were significantly lower in B₂ in comparison
to B₁ (FVC p<0.001, FEV₁ p<0.001, FEV₁/FVC% p< 0.001) and A (FVC p<0.001, FEV₁ p<0.05, FEV₁/
FVC% p<0.001). In addition all the ventilatory variables had significant (p<0.001) negative correlation
with durations of disease except FVC in B₁, which was significant at p<0.01 level. Conclusion: This
study reveals that pulmonary functions may be lower in patients of RA and the lung function is
inversely related to the duration of disease.

Key Words: FVC; FEV₁; Rheumatoid Arthritis

DOI: 10.3329/jbsp.v5i1.5412

J Bangladesh Soc Physiol. 2010 June; 5(1): 8-13