Inflammatory markers and chronic kidney disease

Objective: Background: Resistant hypertension (RHT) defined as an uncontrolled blood pressure (BP) despite the use of 3 or more antihypertensives presents a high cardiovascular (CV) morbidity and mortality and high prevalence of chronic kidney disease (CKD). High BP levels and kidney injury appear to be strongly associated with inflammatory biomarkers. Objective: To evaluate the relationship between inflammatory markers and subclinical and established CKD in a large cohort of patients with RHT Design and method: Cross-sectional study that evaluated 423 resistant hypertensives (30.5% male, mean age 64.0 ± 10.8 years) submitted to renal function assessment (albuminuria dosage and evaluation of glomerular filtration rate calculated from the CKD-EPI formula) and dosage of inflammatory markers: TNF-alpha, MCP-1, E-selectin and PAI-1. Socio-demographic characteristics, anthropometric measurements and CV risk factors were recorded. We considered subclinical CKD those patients with moderately high albuminuria (30–300 mg/g) and/or GFR between 30 and 60 ml/min/1.73m2 and established CKD those who presented albuminuria > 300 mg/g and/or TFG < 30 ml/min/1.73m2. Variance analysis compared serum levels of the 4 inflammatory markers and bivariate analysis compared patients with and without subclinical and established chronic kidney disease. Results: The prevalence of established CKD was 7.3% (31 patients) and subclinical CKD was 47% (187 patients). Patients with subclinical CKD were older and with higher arterial stiffness (higher pulse wave velocity). TNF-alpha (7.1 [4.4–8.6] vs 51, [3.2–7.5]) and MCP-1(284 [220–379] vs 260 [185–359] were significant higher in this group of patients. When we analyzed patients with established CKD, we observed that they have higher BP levels and that TNF-alpha values (7.8 [5.6–14.0] vs 5.6 [3.5–8.3]) and E-selectin (54.4[41.2–61.3] vs. 47.8 [32.0–65.3]) were significantly higher in this group. Conclusions: Among the inflammatory markers evaluated, which was most strongly correlated with subclinical CKD were TNF-alpha and MCP-1, while those with established CKD have higher TNF-alpha and E-selectin levels, possibly pointing out that the MCP-1 is an earlier marker of kidney injury.