Abstract 5217: Endothelial Vasomotor Dysfunction in the Brachial Artery Predicts Development of Early Stage Renal Dysfunction in Patients With Type 2 Diabetes Mellitus
Endothelial dysfunction in renal vasculature is implicated in the pathogenesis of renal failure in type 2 diabetes mellitus (DM). Endothelial dysfunction occurs in systemic vasculature of DM patients, and there may be a relationship between endothelial dysfunction in the brachial artery and renal vasculature. This study examined whether endothelial vasomotor dysfunction in the brachial artery predicts early renal dysfunction in DM patients.
Methods: Flow-mediated endothelium-dependent dilation (FMD, % increase in artery diameter from baseline) in the brachial artery was measured in 275 consecutive DM patients with normal renal function at enrollment (serum creatinine levels [sCr] <1.0 mg/dl, urinary albumin excretion [UAE] < 25 mg/day and estimated glomerular filtration rate [eGFR] ≥ 60 mL/min/1.73 m2 at baseline). They were prospectively followed for 1.5 years. The end point was development of early stage renal dysfunction, defined as occurrence of one or more of the following events: sCr ≥ 1.2 mg/dL, UAE ≥ 30 mg/day and eGFR < 60 mL/min/1.73 m2.
Results: During the follow-up period, early stage renal dysfunction developed in 63 (46.7%) patients with impaired FMD (< 5.2%, 50th percentile of the distribution) and in 17 (12.1 %) patients with the preserved FMD (≥ 5.2%) (p < 0.0001). Using multivariate logistic analysis, the impaired FMD was an independent predictor of the development of early stage renal dysfunction (OR; 5.1, 95%CI; 2.62 - 9.68, p < 0.0001) after adjustment with covariates, including hypertension, age, use of anti-diabetic drugs and CRP levels. Using a c-statistic, the predictive value of impaired FMD was significantly incremental over that of the conventional known risks including hypertension, age, use of anti-diabetic drug and CRP levels for progression of renal dysfunction (area under the ROC curve; 0.88 and 0.72, respectively, p = 0.01). Dilator response of the brachial artery to nitrates had no significant predictive value.
Conclusions: Endothelial vasomotor dysfunction in the brachial artery is an independent predictor of development of early renal dysfunction in DM patients. The measurement of FMD is useful for identifying patients with type 2 DM at risk of developing future renal dysfunction.