Variability of NT-proBNP and Its Relationship with Inflammatory Status in Patients with Stable Essential Hypertension: A 2-Year Follow-Up Study

Background: The variability of NT-proBNP levels has been studied in heart failure, yet no data exist on these changes over time in hypertensive patients. Furthermore, studies on the relationship between natriuretic peptides and inflammatory status are limited. Methodology/Principal Findings: 220 clinically and functionally asymptomatic stable patients (age 59613, 120 male) out of 252 patients with essential hypertension were followed up, and NT-proBNP was measured at baseline, 12 and 24 months. No differences in NT-proBNP were found with respect to the basal stage in the hypertrophic group, but significant changes were found in non-hypertrophic subjects. The reproducibility of NT-proBNP measurements was better in patients with hypertrophy than in the non-hypertrophic group for the three intervals (stage I-basal; stage II-stage I; stage II-basal) with a reference change value of 34%, 35 % and 41%, respectively, in the hypertrophic group. A more elevated coefficient of correlation was obtained in the hypertrophic group than in patients without hypertrophy: basal versus stage I (r = 0.79, p,0.0001 and r = 0.59, p,0.0001) and stage I versus stage II (r = 0.86, p,0.0001 and r = 0.56, p,0.0001). Finally, levels of NT-proBNP significantly correlated with sTNF-R1 (p,0.0001) and IL-6 (p,0.01) during follow-up. A multivariate linear regression analysis showed that sTNF-R1 is an independent factor of NT-proBNP. Conclusions/Significance: This work shows that there is good stability in NT-proBNP levels in a follow-up study o