Relationshep between decrease in night blood pressure, heartrate variability and inflammatory parameters

The lack of nocturnal decline in blood pressure (BP) is associated with an increase in cardiovascular events. In this study, we aimed to evaluate the association of night blood pressure, serum uric acid, the low grade inflammation and cardiac autonomic function in untreated dipper and non-dipper hypertensive patients.Methods: Ninety-two eligible consecutive patients attending for initial evaluation of hypertension were investigated. Ambulatory BP measurements, heart rate variability (HRV) indices obtained over 24 Holter ECG recordings, high sensitive C-reactive protein (hsCRP) and serum uric acid levels (SUA) were measured in all patients. The univariate analyses and then multivariate linear regression analyses were performed.Results: The HRV indices (SDNN, SDANN and Triangular index) were inversely correlated with hsCRP (r=-0.425, p<0.001; r=-0.431, p<0.001; r=-0.361, p<0.001) and night BP measurements (for night mean BP: r=-0.286, p=0.006; r=-0.251, p=0.016; r=-0.234, p=0.025; respectively). SUA levels were positively correlated with night BP measurements (for night mean BP [r= 0.260, p=0.012]; night systolic BP [r= 0.249, p=0.016]; night diastolic BP [r= 0.249, p=0.016]). In multivariate linear regression analyses, hsCRP and age were independent redictors of cardiac autonomic dysfunction (for SDNN: ß=-0.380, p<0.001; and ß=-0.256, p=0.006; respectively) and, SUA and HRV indices were independent predictors of night BP measurements (for night mean BP: SUA, ß=0.276,p=0.006; SDNN, ß=-0.253, p=0.021).Conclusion: Our study findings suggest that the lack of nocturnal decline of BP in hypertensive and normotensive patients is independently associated with SUA levels, low grade inflammation and the autonomic dysfunction. These relationships may play an important role in the pathogenesis of hypertension. Especially, in normotensive or hypertensive with relative low blood pressure patients, this relationshep is important and must be searched.