A study of microalbuminuria in patients with rheumatoid arthritis

Abstract

Background: Rheumatoid arthritis (RA) is a chronic inflammatory disorder with potential systemic complications including renal involvement. Microalbuminuria represents early endothelial dysfunction and may indicate disease severity and cardiovascular risk in RA patients. The aim of the study is to determine the prevalence of microalbuminuria in patients with rheumatoid arthritis and to examine its correlation with disease activity markers including rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). Methods: The study included 40 patients with established rheumatoid arthritis diagnosed according to the 2020 American College of Rheumatology-European Alliance of Associations for Rheumatology (ACR EULAR) classification criteria. Patients underwent comprehensive clinical assessment including detailed history, physical examination with tender and swollen joint counts, and laboratory investigations. Microalbuminuria was assessed using spot morning urine samples with albumin-to-creatinine ratio (ACR) method, defining microalbuminuria as ACR more than or equal to 30 mg/g. Disease activity markers including ESR, CRP, and RF were measured using standard laboratory methods. Statistical analysis was performed using appropriate parametric and non-parametric tests, with p value less than 0.05 considered statistically significant. Results: Microalbuminuria was present in 8 out of 40 patients (20%). Patients with microalbuminuria demonstrated significantly elevated inflammatory markers compared to those without microalbuminuria. Mean ESR was 48.8±13.7 mm/hr in the microalbuminuria-positive group versus 31.6±12.2 mm/hr in the microalbuminuria- negative group (p=0.001). Mean CRP levels were 29.2±8.4 mg/L in microalbuminuria-positive patients compared to 20.06±12.1 mg/L in microalbuminuria negative patients (p=0.05). Rheumatoid factor showed a strong association with microalbuminuria, with 100% (8/8) of microalbuminuria-positive patients being RF positive compared to 62.5% (20/32) of microalbuminuria-negative patients (p=0.038). Conclusion: Microalbuminuria was present in 20% of rheumatoid arthritis patients and showed significant correlations with disease activity markers including ESR, CRP, and RF. These findings establish microalbuminuria as a valuable biomarker of disease severity and systemic inflammation in RA. Routine microalbuminuria screening should be considered in RA patients, especially those with high disease activity or elevated inflammatory markers.