Abstract 5818: Uncovering the Role of Circulating Soluble Receptor for Advanced Glycation End Products in Hypertension: Relationships With Albuminuria
Introduction: The soluble receptor for advanced glycation end-products (sRAGE) participates in the development and acceleration of atherosclerosis, while albuminuria is an established marker of target organ damage.
Hypothesis: Urinary albumin excretion, expressed as the albumin to creatinine ratio (ACR), may be related to sRAGE in essential hypertensives.
Methods: Our population consisted of 80 newly diagnosed untreated non-diabetics with stage I to II essential hypertension [48 men, mean age=52 years, office blood pressure (BP)=145/93 mmHg]. According to the ACR values determined as the mean of two non-consecutive morning spot urine samples, the study population was divided into microalbuminurics (n=27) (mean ACR=30–300 mg/g) and normoalbuminurics (n=53) (mean ACR<30 mg/g). Moreover, in all patients venous blood sampling was performed for estimation sRAGE concentrations.
Results: Microalbuminurics compared to normoalbuminurics were older (53±6 vs 49±5 years, p<0.05), had higher 24-h systolic BP (140±13 vs 132±12 mmHg, p=0.001), while did not differ regarding sex and metabolic profile (p=NS). Moreover, microalbuminurics compared to normoalbuminurics exhibited lower levels of sRAGE (1011±458 vs 1503±931 pg/ml, p<0.003). In the total population, ACR was positively related to age (r=0.345, p=0.004), body mass index (r=0.217, p<0.003) and 24-h systolic BP (r=0.514, p<0.0001), whereas it was negatively correlated with sRAGE (r= −0.275, p=0.018). Regarding sRAGE, it was associated with body mass index (r= −0.241, p=0.003), waist to hip ratio (r= −0.463, p<0.0001) and 24-h pulse pressure (r= −0.372, p=0.001). Multiple regression analysis revealed that age, 24-h systolic BP and sRAGE were the independent predictors of ACR (R2=0.47, p<0.0001). Furthermore, analysis of covariance showed that sRAGE values were significantly different between groups even after adjustment for confounding factors (p<0.05).
Conclusions: In essential hypertension, microalbuminuria is accompanied by attenuated levels of sRAGE, reflecting pronounced vascular dysfunction. Moreover, the close association of sRAGE with ACR, suggests active involvement of sRAGE in atherosclerotic target organ damage progression in non-diabetic essential hypertensives.