Renal functional reserve in patients with Type 1 diabetes mellitus.
OBJECTIVE
Decreased renal functional reserve might precede incipient diabetic nephropathy in patients with Type 1 diabetes. The aim of this study was to assess the relationship between renal functional reserve and easily assessable estimates of systemic endothelial dysfunction in normoalbuminuric patients with Type 1 diabetes and diabetic retinopathy.


METHODS
Renal functional reserve was calculated as the relative change in glomerular filtration rate after protein ingestion. Glomerular filtration rate was measured using pharmacokinetic compartmental analysis of single-shot plasma sinistrin clearance. We measured the activity of von Willebrand factor and concentrations of C-reactive protein and apolipoprotein B, as easily assessable estimates of systemic endothelial dysfunction.


RESULTS
Twenty-two patients were studied. Renal functional reserve was inversely associated with activity of von Willebrand factor (R=-0.431, p=0.045) and, in a multivariate model, with concentration of C-reactive protein (R=0.652, p=0.031).


CONCLUSIONS
Renal functional reserve is inversely associated with concentration of C-reactive protein in normoalbuminuric patients with Type 1 diabetes and diabetic retinopathy. This finding provides evidence that decreased renal functional reserve might reflect endothelial dysfunction. We speculate that decreased renal functional reserve might possibly show as an early marker of diabetic nephropathy.
Zaletel
Jelka
J
Department of Endocrinology, Diabetes and Metabolic Diseases, University Medical Centre Ljubljana, Ljubljana, Slovenia. jelka.zaletel@kclj.si
Cerne
Darko
D
Lenart
Katarina
K
Zitta
Sabine
S
Jürgens
Günther
G
Estelberger
Willibald
W
Kocijancic
Andreja
A
D000328:Adult; D001053:Apolipoproteins / Q000097:blood; D015415:Biomarkers; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D003928:Diabetic Nephropathies / Q000175:diagnosis / Q000209:etiology*; D003930:Diabetic Retinopathy / Q000209:etiology; D004730:Endothelium, Vascular / Q000503:physiopathology; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D014841:von Willebrand Factor / Q000032:analysis
D001053:Apolipoproteins; D015415:Biomarkers; D014841:von Willebrand Factor; D002097:C-Reactive Protein