title: Renal resistance index is a marker of future renal dysfunction in patients with essential hypertension.
abstract: OBJECTIVE
  In patients with essential hypertension (EHT), the intrarenal resistance index (RI) has been shown to be related to the severity of target organ damage (TOD). Cystatin C is has been reported to be related to TOD in EHT. The aim of the present study was to clarify whether the RI predicts future renal function assessed by cystatin C levels in EHT.
  
  
  METHODS
  One-hundred and twelve patients participated. RI and cystatin C were measured at baseline, and 12 months later, cystatin C was measured again.
  
  
  RESULTS
  The patients were divided into 2 groups according to RI value: the low RI group (RI<0.7) and the high RI group (RI> or =0.7). After 12 months, cystatin C levels were significantly elevated in the high RI group, whereas the levels remained unchanged in the low RI group. Stepwise regression analysis using the baseline values of RI, age, pulse pressure, HbA1c, cystatin C, log-transformed (ln) C-reactive protein and ln urinary albumin/creatinine as covariates, showed baseline RI was the only independent determinant of the time-related changes in cystatin C levels.
  
  
  CONCLUSIONS
  This finding suggests that the renal RI may be a marker of future renal dysfunction in EHT.
authors.affiliation: Department of Integrated Medicine and Informatics, Ehime University Graduate School of Medicine, Toon City, Ehime - Japan. okura@m.ehime-u.ac.jp
authors.forename: Takafumi
authors.initials: T
authors.lastname: Okura
authors.forename: Mie
authors.initials: M
authors.lastname: Kurata
authors.forename: Jun
authors.initials: J
authors.lastname: Irita
authors.forename: Daijiro
authors.initials: D
authors.lastname: Enomoto
authors.forename: Masanori
authors.initials: M
authors.lastname: Jotoku
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Nagao
authors.forename: Mitsuko
authors.initials: M
authors.lastname: Koresawa
authors.forename: Shiho
authors.initials: S
authors.lastname: Kojima
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Hamano
authors.forename: Shinichi
authors.initials: S
authors.lastname: Mashiba
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Miyoshi
authors.forename: Jitsuo
authors.initials: J
authors.lastname: Higaki
mesh_terms: D000367:Age Factors; D000368:Aged; D000419:Albuminuria / Q000209:etiology / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood / Q000652:urine; D001794:Blood Pressure; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000097:blood; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D007668:Kidney / Q000098:blood supply*; D007674:Kidney Diseases / Q000097:blood / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012044:Regression Analysis; D012079:Renal Circulation; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D018616:Ultrasonography, Doppler, Duplex; D014655:Vascular Resistance
chemical_list: D015415:Biomarkers; D003404:Creatinine; D055316:Cystatin C; D006442:Glycated Hemoglobin; C525030:CST3 protein, human; C517652:hemoglobin A1c protein, human