title: Renal functional changes in relation to hemodynamic parameters during exercise test in normoalbuminuric insulin-dependent children.
abstract: OBJECTIVE
  To examine the relationship between filtration fraction and systemic vasculopathy, in normoalbuminuric insulin-dependent diabetic adolescents.
  
  
  METHODS
  We calculated filtration fraction from measured glomerular filtration rate and renal plasma flow during a hypotonic saline perfusion test in 30 normotensive adolescent diabetic patients (9-19 years), with a mean duration of diabetes of 7.4 years. Blood pressure and heart rate were measured in basal conditions, during a 24-h ambulatory monitoring and during a dynamic exercise test on a cycle ergometer and peripheral vascular resistance was calculated.
  
  
  RESULTS
  Filtration fraction was increased in the diabetic children compared with controls (30+/-6% vs. 22+/-4%, p<0.001), while renal plasma flow was significantly lower (453+/-133 mL/min/1.73 m2 vs. 593+/-155 mL/min/1.73 m2, p<0.001). Peripheral vascular resistance was significantly higher at peak exercise in diabetic children compared to controls (16.3+/-1.3 mmHg/L min m2 vs. 11.4+/-0.5 mmHg/L min m2, p<0.01).
  
  
  CONCLUSIONS
  These results indicate that in young patients with IDDM, without apparent nephropathy or apparent systemic vasculopathy, filtration fraction is increased, suggesting an increased intraglomerular pressure. The associated reduced decrease of peripheral vascular resistance (increased diastolic blood pressure during exercise) suggests that renal functional abnormalities may be partly explained by a systemic vasculopathy, also present in the kidney.
authors.affiliation: Division of Pediatric Nephrology, University Hospital, Gent, Belgium. ann.raes@ugent.be
authors.forename: A
authors.initials: A
authors.lastname: Raes
authors.forename: D
authors.initials: D
authors.lastname: Matthys
authors.forename: R
authors.initials: R
authors.lastname: Donckerwolcke
authors.forename: M
authors.initials: M
authors.lastname: Craen
authors.forename: S
authors.initials: S
authors.lastname: Van Aken
authors.forename: J
authors.initials: J
authors.lastname: Vande Walle
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D017595:Renal Plasma Flow / Q000502:physiology*; D014655:Vascular Resistance / Q000502:physiology*