Vascular function of the peripheral circulation in patients with nephrosis

Background. Nephrotic syndrome is associated with abnormal lipoprotein meta bolism and increased risk of coronary heart disease. Endothelial dysfunctio n, an early phase of atherogenesis that manifests as impaired flow-mediated dilation (FMD) of the peripheral circulation, may link these associations. Methods. We examined endothelial function of the brachial artery and forear m resistance arteries in 15 patients with nephrosis (NP), 15 patients with primary hyperlipidemia (HL) alone, and 15 normolipidemic, nonproteinuric su bjects (NC) matched for age, sex, and weight. The NP and HL groups had simi lar serum cholesterol and triglyceride concentrations. Postischemic FMD (en dothelium-dependent) and glyceryl trinitrate-mediated dilation (GTNMD: endo thelium-independent) of the brachial artery were studied using ultrasonogra phy and computerized edge detection software. Postischemic forearm blood fl ow was also measured using plethysmography. Results. Postischemic FMD of the brachial artery was significantly lower in the NP and HL groups compared with NC group (mean +/- SE): NP 4.91 +/- 0.8 %, HL 4.53 +/- 0.6%, NC 8.45 +/- 0.5% (P < 0.001). There were no significan t differences among the groups in baseline diameter and GTNMD of the brachi al artery, nor in maximal forearm blood flow and Row debt repayment of the forearm microcirculation. Significant differences in FMD among the groups w ere principally related to differences in serum low-density lipoprotein cho lesterol. Conclusions. Patients with NP have abnormal endothelium-dependent but prese rved endothelium-independent dilation of the brachial artery following an i schemic stimulus. Postischemic forearm microcirculatory function is unimpai red. Dyslipoproteinemia is probably the principal cause of endothelial dysf unction of conduit arteries in patients with NP and the basis for their inc reased risk of cardiovascular disease.