5-10
GFR decline rate of Japanese general population: A 10 year follow-up study: A Longitudinal 10-year Follow-up Study
Enyu Imai1, Masaru Horio2, Kunihiro Yamagata3, Kunitoshi Iseki4, Shigeko Hara5, Nobuyuki Ura6, Yutaka Kiyohara7, Yusuke Tsukamoto8, Sadayoshi Ito9, Hirofumi Makino10, Akira Hishida11 and Seiichi Matsuo12
Department of Nephrology, Osaka University Graduate School of Medicine1), Department of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Osaka2), Department of Nephrology, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki 3), Dialysis Unit, University Hospital of The Ryukyus, Okinawa 4), Health Medical Center, Toranomon Hospital, Tokyo 5), Second Department of Internal Medicine, Sapporo Medical University School of Medicine, Hokkaido6), Department of Environmental Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka7), Syuwa General Hospital8), Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Graduate School of Medicine, Miyagai9), Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama10), First Department of Medicine, Hamamatsu University School of Medicine, Shizuoka11), Department of Nephrology, Nagoya University Graduate School of Medicine12)

Abstract
Prevalence of CKD stage 3 to 5 is considerably higher 18.7% in Japanese compared with 4.5% in the United States population. This study investigated whether this higher prevalence of CKD might reflect to a population-based progressive decline in renal function, in turn to increase a risk of end-stage renal disease in Japanese general population. A decline in renal function was assessed with decline in GFR over 10 years which was estimated with the Japanese-coefficient-modified abbreviated MDRD study equation in 120,727 participants with age 40 and older of annual health-check program between two periods, 1989-1993 and 1998-2003. The rate of decline in GFR in the participants was 0.36 ml/min/1.73m2/year on average. In the presence of hypertension, the mean rate of decline in GFR was significantly higher than the absence only in male population with age 50-79. The rate of decline in GFR was more than two times higher in participants with proteinuria than in participants without proteinuria in both sex. The rate of GFR decline was significantly higher in participants with initial GFR <50 ml/min/1.73m2 among the groups younger than age 70 and in participants with initial GFR <40 ml/min/1.7m2 in the group with older age 70-79. We concluded that decline in renal function in Japanese general population was predicted to be slow from the rate of decline in GFR in 10 years. Hypertension, proteinuria and lower GFR are significant risk factors for greater rate of decline in GFR.

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