Prevalence of Abnormal Liver Function Tests in Rheumatoid Arthritis

Abstract

BACKGROUND Rheumatoid arthritis is a systemic, chronic inflammatory polyarthritis that has high morbidity and mortality. Abnormal liver function tests in rheumatoid arthritis may result from the disease itself, drugs taken to treat the condition, injury caused by alcohol, infections such as viral hepatitis or other autoimmune disease affecting the liver. The burden of liver dysfunction in rheumatoid arthritis needs to be determined in our setting. This study set out to determine the prevalence of abnormal liver function tests in ambulatory patients diagnosed with rheumatoid arthritis at the rheumatology out-patient clinic, Kenyatta national hospital. METHODOLOGY This was a cross-sectional study carried out in the rheumatology out-patient clinic of the Kenyatta national hospital. The study included 107 patients aged 18 years and over diagnosed with Rheumatoid arthritis. Consecutive sampling was used to recruit participants. After obtaining written and informed consent, participants’ records were examined for previous liver function test results, medication used and duration of illness. Demographic data and medical history was collected using a pre-structured data capture form. A disease activity score using the DAS28-ESR scale was done. A brief physical exam to evaluate signs of liver disease and assess joint swelling and tenderness was then followed by collection of a blood sample to conduct liver function tests and erythrocyte sedimentation rate. Data was summarized using tables, pie charts, histograms bar charts and line graphs. Stata version 13 was used for data analysis. The prevalence of abnormal liver function tests was calculated as a percentage of the total liver function test results. Factors associated with liver dysfunction were determined using logistic regression. RESULTS The overall prevalence of abnormal liver function tests in the study population was 57%. The most common abnormal liver function tests were direct bilirubin and alkaline phosphatase, which were elevated in 34.6% and 15% of the study population, respectively. Abnormal direct bilirubin was associated with longer duration of disease, adjusted odds ratio of 0.54 (0.34, 0.86) with a p value of 0.009 and with higher disease activity, adjusted OR 2.79(1.23, 6.25) with a p value of 0.014. Abnormal ALP was significantly associated with BMI with an xiv adjusted OR of 0.205 (0.074, 0.57), p value 0.002 as well as duration of disease, with an adjusted OR 1.14 (1.013, 1.29), p value 0.031. CONCLUSION This study found the prevalence of liver dysfunction in patients with rheumatoid arthritis to be 57% and recommends regular monitoring of liver function tests in patients with rheumatoid arthritis