title: Dynamic evaluation of renal resistive index in normoalbuminuric patients with newly diagnosed hypertension or type 2 diabetes.
abstract: OBJECTIVE
  Renal resistive index is a useful measure for quantifying alterations in renal blood flow. In the present study we evaluated resistive index at baseline and after vasodilation induced by nitroglycerine in normoalbuminuric patients with type 2 diabetes or essential hypertension, relating the values to indices of systemic vascular dysfunction.
  
  
  METHODS
  Newly diagnosed treatment-naïve type 2 diabetic (n = 32) and hypertensive patients (n = 49) were compared with 27 age- and sex-matched healthy controls. Renal resistive index was obtained by duplex ultrasound at baseline and after 25 μg sublingual nitroglycerine. Endothelium-dependent (flow-mediated dilation) and -independent (response to nitroglycerine) vasodilation in the brachial artery was assessed by computerised edge detection system. Carotid-femoral pulse-wave velocity and augmentation index were assessed by applanation tonometry. Nitrotyrosine levels, an index of oxidative stress, were also measured.
  
  
  RESULTS
  Resistive index was higher in diabetic than in hypertensive patients and controls (p < 0.001), while changes in resistive index induced by nitroglycerine were lower in hypertensive patients compared with controls (p < 0.01), and were further reduced in type 2 diabetic patients. Hypertensive and diabetic patients showed significantly increased arterial stiffness, nitrotyrosine levels and reduced endothelial function than controls (p < 0.05). Changes in resistive index induced by nitroglycerine were independently related to serum glucose, reactive hyperaemia and aortic pulse-wave velocity in the overall population.
  
  
  CONCLUSIONS
  These results support the dynamic evaluation of renal resistive index as an early detector of renal vascular alterations in the presence of type 2 diabetes and hypertension, even before the onset of microalbuminuria.
authors.affiliation: Department of Internal Medicine, University of Pisa, Via Roma 67, 56100 Pisa, Italy.
authors.forename: R M
authors.initials: RM
authors.lastname: Bruno
authors.forename: E
authors.initials: E
authors.lastname: Daghini
authors.forename: L
authors.initials: L
authors.lastname: Landini
authors.forename: D
authors.initials: D
authors.lastname: Versari
authors.forename: A
authors.initials: A
authors.lastname: Salvati
authors.forename: E
authors.initials: E
authors.lastname: Santini
authors.forename: I
authors.initials: I
authors.lastname: Di Paco
authors.forename: A
authors.initials: A
authors.lastname: Magagna
authors.forename: S
authors.initials: S
authors.lastname: Taddei
authors.forename: L
authors.initials: L
authors.lastname: Ghiadoni
authors.forename: A
authors.initials: A
authors.lastname: Solini
mesh_terms: D000328:Adult; D000419:Albuminuria / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology*; D001786:Blood Glucose / Q000378:metabolism; D016022:Case-Control Studies; D015897:Comorbidity; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology*; D007668:Kidney / Q000098:blood supply* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000494:pharmacology; D018384:Oxidative Stress / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000097:blood; D014463:Ultrasonography; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D001786:Blood Glucose; D014665:Vasodilator Agents; C002744:3-nitrotyrosine; D014443:Tyrosine; D005996:Nitroglycerin