title: Predictive value of dynamic renal resistive index (DRIN) for renal outcome in type 2 diabetes and essential hypertension: a prospective study.
abstract: BACKGROUND
  Hypertension (EH) and type 2 diabetes (T2DM) are major causes of chronic kidney disease (CKD) and identification of predictors of CKD onset is advisable. We aimed to assess whether dynamic renal resistive index (DRIN), as well as other markers of systemic vascular damage, are able to predict albuminuria onset and estimated glomerular filtration rate (eGFR) decline in patients with T2DM or EH.
  
  
  METHODS
  In this prospective observational cohort study, 27 T2DM and 43 EH patients, free of CKD at baseline, were followed-up for 4.1 ± 0.6 years. Resistive Index (RI), endothelium-dependent (FMD) and independent vasodilation in the brachial artery (after glyceryl trinitrate - GTN - 25 μg s.l.), carotid-femoral Pulse Wave Velocity (PWV), Augmentation Index (AIx), DRIN (%RI change after GTN 25 μg s.l.) were evaluated.
  
  
  RESULTS
  Patients developing microalbuminuria were older, more frequently T2DM, with higher UACR at baseline, and showed higher DRIN (-2.8 ± 6.7 vs -10.6 ± 6.4 %, p = 0.01) and PWV (9.9 ± 1.3 vs 7.9 ± 1.5 m/s, p = 0.004) at baseline. The best predictors of microalbuminuria onset were DRIN > -5.16 % in T2DM (sensitivity 0.83, specificity 0.80) and PWV > 8.6 m/s in EH (sensitivity 0.96, specificity 1.00). Individuals whose eGFR declined (n = 27) had higher eGFR at baseline, but similar vascular characteristics; however in EH showing eGFR decline, baseline DRIN and PWV were higher. PWV showed a steeper progression during follow-up in patients developing albuminuria (Visit-outcome interaction: p = 0.01), while DRIN was early compromised but no further impaired (Visit-outcome interaction: p = 0.04).
  
  
  CONCLUSIONS
  PWV and DRIN are able to predict microalbuminuria onset in newly diagnosed EH and T2DM. DRIN is early compromised in T2DM patients developing microalbuminuria.
authors.affiliation: Institute of Clinical Physiology - CNR, Via Moruzzi 1, 56125, Pisa, Italy. rosam.bruno@gmail.com.
authors.forename: R M
authors.initials: RM
authors.lastname: Bruno
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56124, Pisa, Italy. sonoalcomputer@hotmail.it.
authors.forename: A
authors.initials: A
authors.lastname: Salvati
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56124, Pisa, Italy. marta.barzacchi@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Barzacchi
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56124, Pisa, Italy. k.raimo@soluxioni.it.
authors.forename: K
authors.initials: K
authors.lastname: Raimo
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56124, Pisa, Italy. stefano.taddei@med.unipi.it.
authors.forename: S
authors.initials: S
authors.lastname: Taddei
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56124, Pisa, Italy. lorenzo.ghiadoni@med.unipi.i.
authors.forename: L
authors.initials: L
authors.lastname: Ghiadoni
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56124, Pisa, Italy. anna.solini@med.unipi.it.
authors.forename: A
authors.initials: A
authors.lastname: Solini
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000419:Albuminuria / Q000453:epidemiology / Q000503:physiopathology*; D001916:Brachial Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D005919:Glomerular Filtration Rate; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D007668:Kidney / Q000098:blood supply / Q000000981:diagnostic imaging*; D008875:Middle Aged; D011446:Prospective Studies; D063177:Pulse Wave Analysis; D012077:Renal Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012079:Renal Circulation; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology / Q000503:physiopathology; D014463:Ultrasonography; D014664:Vasodilation / Q000502:physiology*