Relation of C-reactive protein and tumor necrosis factor-alpha to ambulatory blood pressure variability in healthy adults.

Elevated blood pressure (BP) variability has been linked to an increased risk for adverse cardiovascular events, but the biologic factors that promote elevated BP variability are not entirely understood. This cross-sectional study examined whether inflammatory factors might be associated with elevated BP variability during 24-hour ambulatory BP monitoring. Subjects were 140 healthy, normotensive adults. Inflammatory markers included C-reactive protein (CRP) and tumor necrosis factor-alpha. BP variability was calculated as the within-subject SD of BP values obtained during the daytime, nighttime, and 24-hour periods. In linear regression models that were adjusted for mean BP and other factors, CRP quartiles were positively associated with daytime systolic BP variability; for subjects in the lowest to highest CRP quartiles, the mean within-subject SDs of daytime systolic BP were 9.31, 9.62, 10.55, and 11.17, respectively (p for linear trend = 0.001). CRP showed similar positive associations with nighttime and 24-hour systolic BP variability. In contrast, tumor necrosis factor-alpha was not independently associated with systolic BP variability during any of the time periods. With respect to diastolic BP variability, significant positive associations were found between CRP and diastolic BP variability during all time periods and between tumor necrosis factor-alpha and daytime diastolic BP variability. In conclusion, there are positive associations between markers of inflammation and BP variability in healthy, normotensive adults, suggesting that inflammation may be 1 of the factors that promotes increased BP variability.