Assessment of PEFR and FEF 2575 in Female SLE Patients and their Relationship with Duration of the Disease

Background: Systemic Lupus Erythematosus (SLE) is an autoimmune disorder which affects multiple organs of human including lungs. Objectives: To assess PEFR and FEF25-75 in SLE patients and to correlate them with the duration of the disease. Method: This cross-sectional study was carried out in the Department of Physiology, BSMMU, Dhaka, from January 2010 to December 2010. A total number of 120 female subjects were selected, among which 30 were age and BMI matched apparently healthy subjects for comparison (control) and 90 were patients of SLE (study group). All the patients were matched for age, sex and BMI. Based on the duration of the disease, patients were subdivided into B1 (1-6 months), B2 (2-5 years) and B3 (6-10 years). Controls were selected from the community and the patients from the Out Patient Department (OPD) of SLE clinic, Department of Medicine, BSMMU, Dhaka. (PEFR) and FEF25-75 of all the subjects were measured by a Digital MicroDL spirometer. For statistical analysis Independent Sample ‘t’ test, One way ANOVA test and Pearson’s correlation coefficient test were performed as applicable. Results: The mean percentage of predicted values of lung function parameters in healthy female subjects were within normal ranges. The mean percentage of predicted values of PEFR and FEF25-75 were significantly lower in all study groups when compared to control. Again, the mean percentage of predicted values of PEFR and FEF25-75 were significantly lower in the patients of Group B3 compared to Group B2. Moreover, these comparisons were significantly lower when compared to Group B1. The differences of the mean percentage of predicted value of PEFR, FEF25-75 were non-significantly lower in Group B2 when compare to Group B1. In addition, FEF25-75 were positively correlated with duration of SLE in group B2 but negatively correlated in B3. On the other hand PEFR was negatively correlated with duration of SLE in both B2 and B3. All these values were statistically non-significant. Conclusion: These pulmonary functions decrease in SLE female and the reduction is inconsistently associated with duration of the disease.

Introduction: Systemic lupus erythematosus (SLE) is a multisystem disorder in which pleuropulmonary involvement is very common.SLE is about nine times as common in women as in men 1 .They also suggested that, the peak age of onset of this multisystemic disorder might be 20 to 50 years.The prevalence of SLE in the USA is approximately 15 to 50/100000 of which highest is among African Americans 2 .In other population the prevalence varies between 1:1000 and 1:10000 1 .In India found a point prevalence of 3 per 100000 3 .There is no standard statistical data in SLE in Bangladesh 3 .SLE may affect all the components of the respiratory system, including upper airways, lung parenchyma, pulmonary vasculature, pleura, and respiratory muscles 4,5 .The clinical presentation of lung involvement ranges from mild, self-limited, pleuritic chest pain to fatal pulmonary hemorrhage 6 .Subclinical pulmonary involvement has been reported from autopsy series with a prevalence of 93% 7 .A few percentages (4-5%) of SLE patients with lung disease have the clinical symptoms of lung disease 8 .Lung involvements may exaggerate gradually and may be the vital cause of morbidity and mortality of SLE patient 9 .Large numbers of subjects in Bangladesh are affected by SLE.Usually they are treated by the physician with an aim to relieve the symptoms ignoring the prevention of pulmonary complications.For that cause, pulmonary involvement in SLE may remain undiagnosed for a long period.Early diagnosis of lung involvement is beneficial in most patients for therapy and could have an important effect on therapeutic strategies 4,31 .Therefore early detection of lung involvement is important in patients with SLE 4 .Many researchers have investigated pulmonary functions in this group of patient abroad 5,10-16 .In our country, several investigators studied on SLE 3,17 .With the best of our knowledge, no such study has been undertaken to explore the pulmonary function status in SLE patients in Bangladesh.The aim of the present study was to investigate the pulmonary involvement of SLE patients whose do not have the clinical symptoms and sign of lung disease.This study also observed the extent of lung involvement with the duration of SLE.The outcome of this study may act as a source of background information for guiding the clinicians about the risk of pulmonary complications while treating the SLE patients.Method: For this study, 90 female patients of SLE were selected from the Out Patient Department (OPD) of SLE clinic, Department of Medicine, BSMMU, Dhaka (study group).The study group was selected according to the updated American College of Rheumatology (ACR) revised criteria of SLE 18 .In this study, the study population was subdivided into B 1 (1-6 months), B 2 (2-5 years) and B 3 (6-10 years) on the basis of duration of disease.Disease duration was characterized as the duration from the date of physician diagnosis until the date at first study visit.For comparison, 30 ages (20 to 40 years), BMI (19.73 to 25.6 kg/m 2 ) matched apparently healthy female persons (control) were collected from different areas of Dhaka city by personal contact.After selection, all the subjects were thoroughly informed about the aim, benefit and study procedure.Informed written consent was obtained.she was requested to attend the Department of Physiology at 7.30 am in a fasting state on the day of examination.Then she was requested to attend the Department of Physiology at 7.30 am in a fasting state on the day of examination.A detail personal, medical, family, socioeconomic, occupational and dietary history was recorded in a preformed questionnaire.Thorough physical examination was done and documented.Any subject with diabetes mellitus (Fasting plasma glucose >7 mmol/dl 19 )

Groups p value p value
A   I).The mean percentage of predicted values of PEFR and FEF 25-75 were significantly (p<0.001)lower in all study groups when compared to control.Again, the mean percentage of predicted values of PEFR was significantly lower in the patients of Group B 3 compared to Group B 2 (P<0.05) and Group The present study was undertaken to observe spirometric pulmonary function in female patients of SLE.In this study, values of lung function parameters of healthy subjects were within physiological limit and were almost similar to those reported by different investigators of abroad 14 as well as in our country 22,18 .PEFR were significantly (p<0.001)lower in patients of SLE with different duration than those of healthy control subjects.Again, this parameter was lower in patients of 2-5 years duration compared to patients of 1 to 6 months duration.However, this ventilatory parameter was significantly lower in patients of SLE with 6-10 years duration compared to 1 to 6 months duration (p<0.001) and 2-5 years duration (p<0.05).No similar observation was available for comparison.FEF 25-75 in different groups of patients was significantly (p<0.001)lower than those of control subjects.This finding was consistent to the finding of other investigators 10, 16, 24 .Again, this parameter was lower in patients of 2-5 years duration compared to patients of 1 to 6 months duration.On the other hand, this ventilatory parameter was significantly lower in patients of SLE with 6-10 years duration compared to 1 to 6 months duration (p<0.01) and 2-5 years duration (p<0.01).This finding was consistent to the finding of other investigators 16 .

B 1 (
p<0.001) and also the mean percentage of predicted values of FEF 25-75 was significantly lower in the patients of Group B 3 compared to Group B 2 (P<0.01) and Group B 1 (P<0.01).The differences of the mean percentage of predicted value of PEFR, FEF 25-75 were non significantly( p > 0.05) lower in Group B 2 when compare to Group B 1 .Correlation of the study variables with the duration of the disease in SLE are shown in Figure III and IV.FEF 25-75 were positively correlated with duration of SLE in group B 2 but negatively correlated in B 3 on the other hand PEFR was negatively correlated with duration of SLE in both B 2 and B 3 .All these values were statistically non significant Discussion:

Figure III :
Figure III: Correlation of percentage predicted value of PEFR with duration of SLE in different groups (n = 60) or with H/O diagnosis of systemic hypertension (SBP ?140 and DBP ?90 mm ofHg 20 ), with H/O any pulmonary comorbidity (e.g, bronchiectasis, pulmonary fibrosis, pneumonectomy, lobectomy) or any other systemic disease (e.g, rheumatoid arthiritis, connective tissue disorder) or with H/O any heart disease, renal insufficiency(?1.5mg/dl) were excluded from the study 21 .All the subjects were under drug treatment and do not have the clinical symptoms and sign of lung disease.Then the subject was examined for the lung function parameters by using a Digital Spirometer, described by Clement Clark International, in the Respiratory laboratory of Department of Physiology, BSMMU (Annexure-1).Lung function was assessed by Peak expiratory flow rate (PEFR) and Forced mid expiratory flow of FVC (FEF 25-75 ).Data were expressed as mean ± SD (Standard deviation).One-way ANOVA test was done to compare among the groups and Independent sample't' test was done to compare between the groups.Pearson's Correlation Coefficient test was done to correlate the spirometric variables with duration of disease.p value <0.05 was accepted as level of significance.Results: The mean± SD of age and BMI of all the

Table I : Age and BMI in different groups (n=120) Statistical analysis: subjects
were almost similar and groups were matched for age and BMI (Table duration of SLE.These indicated that duration of disease influences the degree of deterioration of lung but were not supported by the significant negative correlation of these parameters with duration of SLE.Conclusion:This study revealed that pulmonary ventilatory functions are lower in female patients of SLE as shown by lower percentage of predicted values of lung function parameters like PEFR & FEF 25-75 in comparison to the values of healthy female subjects.All these functional decrement may be the consequence of interstitial fibrosis as well as bronchial narrowing, neurological involvement or respiratory muscle weakness as a result of the involvement of lung structure in widespread chronic inflammatory process of SLE.These values are not signifacently Furthermore, some lung function is inversely related to the duration of disease and some are directly related to the duration of disease.Therefore, from this study it may be concluded that pulmonary function decrease in SLE female and the reduction is inconsistently associated with duration of the disease.