Augmentation index, a predictor of cardiovascular events, is increased in children and adolescents with primary nephrotic syndrome

Background Arterial stiffness is associated with an increased risk of cardiovascular diseases. Augmentation index (AIx@75), a measure of arterial stiffness and wave reflection, has not been evaluated in patients with primary nephrotic syndrome (PNS). We investigated whether central and peripheral vascular profiles, hemodynamic parameters, and biochemical tests are associated with AIx@75 in PNS patients. Methods This observational study involved 38 children and adolescents with PNS (12.14 +/- 3.65 years) and 37 healthy controls (13.28 +/- 2.80 years). Arterial stiffness and vascular and hemodynamic parameters were measured noninvasively using the Mobil-O-Graph (R) (IEM, Stolberg, Germany). In the PNS group, biochemical tests and corticosteroid dosage/treatment time were analyzed. Results Peripheral and central systolic blood pressure (SBPp, SBPc) Z-scores were significantly higher in the PNS patients. AIx@75 was significantly higher in the PNS patients (25.14 +/- 9.93%) than in controls (20.84 +/- 7.18%). In the control group, AIx@75 negatively correlated with weight (r = - 0.369; p = 0.025), height (r = - 0.370; p = 0.024), and systolic volume/body surface (r = - 0.448; p = 0.006). In the PNS group, a univariate linear correlation showed that AIx@75 negatively correlated with weight (r = - 0.360; p = 0.027), height (r = 0.381; p = 0.18), and systolic volume/body surface (r = - 0.447; p < 0.002) and positively with the Z-score of SBPp (r = 0.407; p = 0.011), peripheral diastolic blood pressure (DBPp, r = 0.452; p = 0.004), SBPc (r = 0.416; p = 0.009), DBPc (r = 0.407; p = 0.011), triglycerides (r = 0.525; p = 0.001), and cholesterol [total (r = 0.539; p < 0.001), LDLc (r = 0.420; p = 0.010), and non-HDLc (r = 0.511; p = 0.001)]. Conclusions Early abnormalities of AIx@75 and vascular parameters suggest that patients with PNS, even in stable condition, present subclinical indicators for the development of cardiovascular disease.