Rheumatoid arthritis can lead to rapid worsening of kidney function, finds study

Patients with rheumatoid arthritis (RA) are more likely to develop reduced estimated glomerular filtration rate (eGFR) than the general population. Decreased eGFR is associated with a higher risk of cardiovascular disease and mortality independent of traditional cardiovascular risk factors in RA. Because there is evidence that the inflammatory process might contribute to decreased kidney function, chronic inflammation might cause kidney damage in patients with RA.

Thus, researchers aimed to identify the associations of disease activity with eGFR in patients with RA. This longitudinal cohort study used data derived from a multicenter registry of patients with RA in Japan. Patients with RA, eGFR ≥ 15 mL/min/1.73 m2 at baseline, and ≥2 assessments of eGFR were included. The DAS28-CRP (disease activity score in 28 joints using C-reactive protein) was used as a continuous exposure variable for the primary analysis. eGFR, calculated using an equation approved by the Japanese Society of Nephrology, was the primary outcome.

Results highlighted some interesting facts.

• Patients with low disease activity or remission had longer disease duration than patients with high or moderate disease activity.
• Corticosteroid and NSAID use was less frequent in patients with low disease activity or remission. Although patients with higher DAS28-CRP had better eGFR at baseline (by 1.698 mL/min/1.73 m2 ), they had a significantly worse longitudinal eGFR trajectory (difference in slopes per 1 unit greater DAS28-CRP, 0.167 [95% CI, 0.062-0.272] mL/min/1.73 m2 per year; P = 0.002).
• Although as expected, RA patients in general had progressive eGFR decreases as they got older, patients who achieved remission or low disease activity had a slower rate of eGFR loss compared to patients with moderate or high disease activity (−0.817 vs −1.283 mL/min/1.73 m2 per year; P < 0.001; ).
• The association of DAS28-CRP with the eGFR trajectory was dose-dependent (−0.723, −0.821, −1.041, and −1.386 mL/min/1.73 m2 per year for remission and low, moderate, and high disease activity, respectively; ).

"In conclusion, lower disease activity was associated with a slower rate of eGFR decline, but clinicians must recognize that even RA patients in remission have progressive eGFR decline as they get older. Considering additional measures to protect kidney function, such as avoiding nephrotoxic medications and treating cardiovascular risk factors, is thus also important."the research team concluded.

For full article follow the link: 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

Source: American Journal of Kidney Diseases