Prevalence of chronic kidney disease and administration of RA-related drugs in patients with RA: The NinJa 2012 study in Japan

Abstract

Objectives: To estimate the prevalence of chronic kidney disease in patients with rheumatoid arthritis (RA) and the administration of disease-modifying anti-rheumatic-drugs (DMARDs), using data from the National Database of Rheumatic Disease by iR-net in Japan (NinJa) 2012 study.

Methods: From a total of 11,940 RA patients, 7135 who underwent an estimated glomerular filtration rate (eGFR) test were studied. Renal dysfunction staging was assessed using Japanese eGFR equations and classified according to the Kidney Disease Improving Global Outcomes 2012 clinical practice guideline.

Results: The prevalence of GFR stages was as follows: stage G1, 25.4%; stage G2, 55.9%; stage G3, 17.5%; stage G4, 0.8%; and stage G5, 0.2%. Overall, 92.7% of patients received at least one DMARD. Sulfasalazine, tacrolimus, and biologics (except inflixmab) were administered in all GFR stages. Methotrexate was not prescribed in patients with stage G5, but methotrexate 3.5 mg/week (mean) was prescribed in four patients (6.8%) with stage G4. Non-steroidal anti-inflammatory drugs and glucocorticoids were prescribed in 40.5% and 43.7% of patients, respectively.

Conclusion: The prevalence of kidney disease in this large sample of RA patients was higher than that in the general population, and the results suggest that RA patients with renal dysfunction require careful drug selection.

Keywords:

• Epidemiology
• Renal dysfunction
• Rheumatoid arthritis
• Rheumatoid arthritis-related drugs

Acknowledgments

The authors thank Mayumi Yokoyama for expert technical assistance. The authors acknowledge the assistance of following clinicians who have referred patients to NinJa: Drs Shoji Sugii, Atsushi Kaneko, Yukihiko Saeki, Yasuhiko Yoshinaga, YasuoSuenaga, Toshihiro Matsui, Toshihito Mori, Kenji Ichikawa, Fuminori Hirano, Yukitomo Urata, Noriyuki Chiba, Yoshiaki Kuga, Takao Sugiyama, Makoto Sueishi, Kumiko Akiyama, Ryutaro Matsumura, Sakae Tanaka, Yuho Kadono, Tetsuharu Sawada, Mitsumasa Kishimoto, Kota Shimada, Megumi Unno, Hiroshi Tsutani, Isao Matsushita, Tomotaro Sato, Masao Katayama, Kunikazu Ogawa, Koichiro Omura, Shiro Oshima, Jun Hashimoto, Kazutaka Izawa, Koichiro Tabaha, Hajime Sano, Shinichiro Tsoumada, Akira Okamoto, Susumu Nishi, Takao Yamanaka, Yuji Moriya, Toru Koyama, Kanuri Matsumori, Takeharu Tonai, Shigeru Yoshizawa, Eiichi Suematsu, Tomoya Miyamura, Taiichiro Miyashita, Satoru Motokawa, Yojiro Kawabe, Eiji Uechi, Issaku Toyohara, Akira Kashiwagi, Noburo Hagino, Yoshiki Shiohira, Jinju Nishino, and Akiko Komiya.

Conflict of interest

This work was supported in part by Health Science Research Grants from the Ministry of Health, Labour and Welfare of Japan to Shigeto Tohma.