Patients with active rheumatoid arthritis (RA) may experience faster decline in kidney function, a new Japanese study finds.
Among 2269 patients with RA (78.4% women; mean age 61.4 years) in the ANSWER cohort study, mean estimated glomerular filtration rate (eGFR) at baseline was 78.5 mL/min/1.73 m2 based on the Japanese Society of Nephrology equation. Investigators assessed RA disease activity score in 28 joints per individual using C-reactive protein (DAS28-CRP) during a median 15.2 months.
Kidney function declined by a significant 0.167 mL/min/1.73 m2 more per year per 1-unit increase in DAS28-CRP, Akira Onishi, MD, PhD, MPH, of Kobe University Graduate School of Medicine in Kobe, Japan, and colleagues reported in the American Journal of Kidney Diseases. Higher RA activity significantly correlated with the greatest annual eGFR decline followed by moderate and low RA activity: -1.386 vs -1.041 vs -0.821 mL/min/1.73 m2 per year, respectively. Even RA remission was associated with an eGFR decline of -0.723 mL/min/1.73 m2 per year. Older age, higher baseline eGFR, and disease duration less than 5.1 years more strongly associated with faster eGFR decline. During the study, no patients died, required a kidney transplant, or initiated dialysis.
Dr Onishi and his colleagues adjusted results for confounders, including age, sex, RA duration, rheumatoid factor, anti-citrullinated peptide antibodies, and use of disease-modifying anti-rheumatic drugs, prescription nonsteroidal anti-inflammatory drugs (NSAIDs), and corticosteroids. They did not assess urinary protein and albumin or use of over-the-counter NSAIDs, however, which is a study limitation.
Although lower RA activity was associated with a slower rate of eGFR decline, Dr Onishi’s team cautioned that even RA patients in remission have progressive eGFR impairment as they get older.
“Considering additional measures to protect renal function, such as avoiding nephrotoxic medications and treating cardiovascular risk factors, are thus also important.”
Disclosure: This research was supported by AbbVie G.K., Asahi Kasei Pharma, AYUMI Pharmaceutical Co., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Janssen Pharmaceutical K.K., Ono Pharmaceutical Co., UCB Japan Co. Ltd., Teijin Healthcare Limited, and Sanofi. Please see the original reference for a full list of disclosures.
Onishi A, Akashi K, Yamamoto W, et al. The association of disease activity and estimated GFR in patients with rheumatoid arthritis: findings from the ANSWER study. Am J Kidney Dis. Published online May 10, 2021. doi:10.1053/j.ajkd.2021.02.338