SP338
AGE AND MALNUTRITION MARKERS ARE PREDICTORS OF ARTERIAL STIFFNESS IN ADULTS WITH AND WITHOUT CHRONIC KIDNEY DISEASE

Introduction and Aims: Arterial stiffness, as marker of subclinical vascular disease, is increasingly acknowledged in the setting of chronic kidney disease (CKD) and was associated with increased cardiovascular (CV) and renal risk. However, conflicting data about its potential contributors in CKD exist. Therefore, we aimed to explore the relationship among various traditional and novel CV risk factors with cardio-ankle vascular index (CAVI, as index of arterial stiffness) in non-dialysis CKD patients and matched controls.

Methods: One hundred thirty-five clinically stable patients (59% male, 61 [47-71] years, 21% non-CKD, 7% CKD stage 2, 37% CKD stage 3, 23% CKD stage 4, and 12% CKD stage 5) prospectively entered this cross-sectional study. Atrial fibrillation and renal replacement therapy were exclusion criteria. CAVI was measured by automatic waveform analyzer (VaSera VS-1000) and a value >9 was considered indicative of arterial stiffness. Medical history (for CKD vintage, cardiovascular, metabolic and primary kidney diseases), body mass index (BMI) and blood pressure measurement were obtained. Plasma mineral metabolism parameters (total calcium, phosphate - PO4, intact parathyroid hormone, calcidiol - 25OHD, total alkaline phosphatase), serum lipid status (total cholesterol, triglycerides), serum albumin, C-reactive protein (CRP), estimated GFR (abbreviated MDRD formula) and urinary albumin to creatinine ratio were measured. Spearman rank correlation and multiple regression analysis were used to test associations.

Results: Overall, 74% subjects had arterial hypertension, 47% - at least one atherosclerotic manifestation, 21% - diabetes mellitus, 25% - obesity, 7% - malnutrition, and 13% were active smokers, with similar prevalence in both CKD and non-CKD groups. Increased CAVI was found in 73% patients (62% in non-CKD vs. 75% in CKD subjects, p=0.16, with similar proportions along CKD stages). In bivariate analysis, a strong positive association of CAVI with age (rs=0.69, p<0.001), but no relationships with estimated GFR and any of the other study parameters were found. However, multivariate regression analysis retained Log(age) (B=0.49; 95%CI 0.40 to 0.57, p<0.001), Log(PO4) (B=-0.23; 95%CI -0.37 to -0.10, p=0.001), and Log(BMI) (B=-0.19; 95%CI -0.34 to -0.03, p=0.02) as independent determinants of Log(CAVI) in a model that accounted for 49% of its variation (p<0.001). Therefore, higher age, lower BMI and lower PO4 predicted arterial stiffness in the investigated cohort.

Conclusions: Arterial stiffness is common in older patients with high prevalence of atherosclerotic disease, irrespective of CKD presence and severity. Besides the expected association with aging, malnutrition (as suggested by lower serum phosphate and BMI) seems to contribute to the decrease of arterial elastic properties in non-dialysis patients with various degrees of glomerular filtration rate decline.