Abstract
Aims/Introduction: Although increases in urinary protein excretion generally precede a decline in the glomerular filtration rate, non-proteinuric renal impairment is common in patients with diabetes. In the present study, we examined the relationship between indices of arterial stiffness and renal function in type 2 diabetic patients without proteinuria. METHODS: Blood sampling, 24-h urine collection, brachial-ankle pulse wave velocity, and 24-h ambulatory blood pressure monitoring were performed in type 2 diabetic patients without overt proteinuria. The ambulatory arterial stiffness index was calculated as (1 - the regression slope of diastolic/systolic ambulatory blood pressure). Estimated glomerular filtration rate (eGFR)was calculated using the simplified prediction equation proposed by the Japanese Society of Nephrology. RESULTS: Of 213 non-proteinuric patients with type 2 diabetes, 60 (28.2%) had a reduced eGFR (<60 mL/min per 1.73 m(2)). Although the urinary albumin excretion rate was significantly correlated with the eGFR, 34 of 152 patients with normoalbuminuria (22.4%) had a reduced eGFR. The eGFR was significantly and negatively correlated with the ambulatory arterial stiffness index and brachial-ankle pulse wave velocity, but not with 24-h pulse pressure. Multivariate analysis revealed that increased age and increased urinary albumin excretion were independently associated with decreased eGFR. In addition, the ambulatory arterial stiffness index, but not brachial-ankle pulse wave velocity, were found to be independently and significantly associated with eGFR. CONCLUSIONS: Ambulatory arterial stiffness index is a marker for increased risk of renal failure in non-proteinuric patients with type 2 diabetes. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00146.x, 2012).