title: Time-to-effect relationships between systolic blood pressure and the risks of nephropathy and retinopathy in patients with type 2 diabetes.
abstract: OBJECTIVE
  To analyze time-to-effect relationships between systolic blood pressure (SBP) and the risks of development of nephropathy and retinopathy in patients with type 2 diabetes.
  
  
  METHODS
  We retrospectively enrolled 647 patients with type 2 diabetes who first visited our hospital between 1995 and 1996, made ≥1 hospital visit per year, had been followed-up for ≥1year, and had undergone ≥4 SBP measurements. Of these, 352 with normoalbuminuria and 516 without retinopathy were followed through June 2012.
  
  
  RESULTS
  Nephropathy developed in 90 patients and retinopathy in 113. Hazard ratios (HRs) for time-dependent SBP-associated nephropathy and retinopathy were the highest during 1year preceding each endpoint or censoring. The HRs for nephropathy had been steadily lower during the preceding 1-17 years, while that for retinopathy had been lower during the preceding 1-5 years and constant during the preceding 5-17 years.
  
  
  CONCLUSIONS
  The time-to-effect relationship with SBP differed for the development of nephropathy and retinopathy. The long-term effect was obvious for nephropathy and borderline for retinopathy, while the short-term effect was stronger and evident for both. Continuous SBP lowering is necessary to prevent nephropathy, whereas SBP control during the preceding 5years seems to be important to prevent retinopathy.
authors.affiliation: Division of Diabetes and Metabolism, The Institute for Adult Diseases, Asahi Life Foundation, Tokyo, Japan. Electronic address: t-takao@asahi-life.or.jp.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Takao
authors.affiliation: Department of Biostatistics, School of Public Health, University of Tokyo, Tokyo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Matsuyama
authors.affiliation: Department of Public Health and Environmental Medicine, The Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Machi
authors.initials: M
authors.lastname: Suka
authors.affiliation: Department of Public Health and Environmental Medicine, The Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yanagisawa
authors.affiliation: Division of Diabetes and Metabolism, The Institute for Adult Diseases, Asahi Life Foundation, Tokyo, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kikuchi
authors.affiliation: Division of Diabetes and Metabolism, The Institute for Adult Diseases, Asahi Life Foundation, Tokyo, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Kawazu
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology*; D003928:Diabetic Nephropathies / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D003930:Diabetic Retinopathy / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors
keywords: Blood pressure; Legacy effect; Nephropathy; Retinopathy; Time-to-effect; Type 2 diabetes