Published in:
01-12-2013 | Original Article
Japan Diabetic Nephropathy Cohort Study: study design, methods, and implementation
Authors:
Kengo Furuichi, Miho Shimizu, Tadashi Toyama, Daisuke Koya, Yoshitaka Koshino, Hideharu Abe, Kiyoshi Mori, Hiroaki Satoh, Masahito Imanishi, Masayuki Iwano, Hiroyuki Yamauchi, Eiji Kusano, Shouichi Fujimoto, Yoshiki Suzuki, Seiya Okuda, Kiyoki Kitagawa, Yasunori Iwata, Shuichi Kaneko, Shinichi Nishi, Hitoshi Yokoyama, Yoshihiko Ueda, Masakazu Haneda, Hirofumi Makino, Takashi Wada, Research Group of Diabetic Nephropathy, Ministry of Health, Labour, and Welfare of Japan
Published in:
Clinical and Experimental Nephrology
|
Issue 6/2013
Login to get access
Abstract
Background
Diabetic nephropathy, leading to end-stage renal disease, has a considerable impact on public health and the social economy. However, there are few national registries of diabetic nephropathy in Japan. The aims of this prospective cohort study are to obtain clinical data and urine samples for revising the clinical staging of diabetic nephropathy, and developing new diagnostic markers for early diabetic nephropathy.
Methods
The Japanese Society of Nephrology established a nationwide, web-based, and prospective registry system. On the system, there are two basic registries; the Japan Renal Biopsy Registry (JRBR), and the Japan Kidney Disease Registry (JKDR). In addition to the two basic registries, we established a new prospective registry to the system; the Japan Diabetic Nephropathy Cohort Study (JDNCS), which collected physical and laboratory data.
Results
We analyzed the data of 321 participants (106 female, 215 male; average age 65 years) in the JDNCS. Systolic and diastolic blood pressure was 130.1 and 72.3 mmHg, respectively. Median estimated glomerular filtration rate (eGFR) was 33.3 ml/min/1.73 m2. Proteinuria was 1.8 g/gCr, and serum levels of albumin were 3.6 g/dl. The majority of the JDNCS patients presented with preserved eGFR and low albuminuria or low eGFR and advanced proteinuria. In the JRBR and JKDR registries, 484 and 125 participants, respectively, were enrolled as having diabetes mellitus. In comparison with the JRBR and JKDR registries, the JDNCS was characterized by diabetic patients presenting with low proteinuria with moderately preserved eGFR.
Conclusions
There are few national registries of diabetic nephropathy to evaluate prognosis in Japan. Future analysis of the JDNCS will provide clinical insights into the epidemiology and renal and cardiovascular outcomes of type 2 diabetic patients in Japan.