Renal Hyperfiltration and Arterial Stiffness in Humans With Uncomplicated Type 1 Diabetes

Abstract

OBJECTIVE We have reported that renal hyperfiltration is associated with endothelial dysfunction in early type 1 diabetes. However, the relationship between renal hyperfiltration and arterial stiffness is unknown. Accordingly, we measured arterial stiffness in type 1 diabetic subjects with hyperfiltering (n = 20) or normofiltering (n = 18). RESEARCH DESIGN AND METHODS Augmentation index (AIx), aortic pulse wave velocity (PWV), renal hemodynamic function (inulin and paraaminohippurate clearances), and urinary and circulating plasma cGMP were measured in normoalbuminuric subjects with type 1 diabetes during clamped euglycemia (glucose 4–6 mmol/l) and hyperglycemia (glucose 9–11 mmol/l). RESULTS During clamped euglycemia, hyperfiltering subjects (glomerular filtration rate ≥135 ml/min/1.73 m2) exhibited lower AIx values (−6.1 ± 2.9 vs. 13.9 ± 2.7%, P = 0.001) and higher cGMP levels in urine and plasma compared with normofiltering subjects. These differences were maintained during clamped hyperglycemia. As expected, renal hemodynamic responses to clamped hyperglycemia were exaggerated in normofilterers, but values for AIx remained unchanged. CONCLUSIONS Renal hyperfiltration is associated with reduced arterial stiffness in subjects with uncomplicated type 1 diabetes.