Twenty-Four-Hour Blood Pressure Variability Is Associated With Lower Cognitive Performance in Young Women With a Recent History of Preeclampsia

Abstract

Background: Women with a history of preeclampsia (hxPE) exhibit sustained arterial stiffness and elevated blood pressure postpartum. Aortic stiffness and 24-hour blood pressure variability (BPV) are associated with age-related cognitive decline. Although hxPE is related to altered cognitive function, the association between aortic stiffness and BPV with cognitive performance in young women with hxPE has not been investigated. The objectives of this study were to (i) test whether cognitive performance is lower in young women with hxPE and (ii) determine whether aortic stiffness and BPV are associated with cognitive performance independent of 24-hour average blood pressure.

Methods: Women with hxPE (N = 23) and healthy pregnancy controls (N = 38) were enrolled 1-3 years postpartum. Cognitive performance was assessed in domains of memory, processing speed, and executive function. Twenty-four-hour ambulatory blood pressure monitoring and carotid-femoral pulse wave velocity (cfPWV) were used to measure BPV and aortic stiffness, respectively.

Results: Women with hxPE had slower processing speed (-0.56 ± 0.17 vs. 0.34 ± 0.11 Z-score, P < 0.001) and lower executive function (-0.43 ± 0.14 vs. 0.31 ± 0.10 Z-score, P = 0.004) compared with controls independent of education, whereas memory did not differ. BPV and cfPWV (adjusted for blood pressure) did not differ between women with hxPE and controls. Greater diastolic BPV was associated with lower executive function independent of 24-hour average blood pressure and education in women with hxPE (r = -0.48, P = 0.03) but not controls (r = 0.15, P = 0.38).

Conclusions: Select cognitive functions are reduced postpartum in young women with a recent hxPE and linked with elevated 24-hour diastolic BPV.

Keywords: ambulatory blood pressure monitoring; blood pressure; hypertension; postpartum; pregnancy/preeclampsia; pulse wave velocity.

Graphical Abstract

Figure 1.

Indices of 24-hour blood pressure variability. X₁, X₂, …, X_n represent a set of blood pressure recordings over a 24-hour period; $\overline{X}$ represents the mean value of a set of 24-hour blood pressure measurements. Abbreviation: ABPM, ambulatory blood pressure monitoring. SD represents the standard deviation of BP measurements within a measurement period and reflects the overall dispersion of blood pressure values; wSD represents the day and night SD weighted for the duration of day and night recordings, which removes the variability introduced by beneficial blood pressure dipping. CV represents the SD of 24-hour blood pressure normalized to the corresponding 24-hour average blood pressure. ARV represents the average of the absolute difference between consecutive blood pressure measurements and is sensitive to the temporal order of blood pressure recordings including faster fluctuations.

Figure 2.

Cognitive performance in women with a history of preeclampsia compared with healthy pregnancy controls. Analysis of covariance was performed to compare cognitive performance in memory, processing speed, and executive function in women with a history of preeclampsia (N = 23; closed circles) and healthy pregnancy controls (N = 38; open circles) controlling for years of education and body mass index. Results represented as individual data points with line at group mean.

Figure 3.

Association between diastolic blood pressure variability (BPV) and executive function. Multiple linear regression was performed with corresponding interaction term (preeclampsia history × diastolic BPV) to determine whether the association between BPV and executive function differed in women with a history of preeclampsia. Years of education, body mass index, and 24-hour average diastolic blood pressure were included in the model as covariates (Table 3). Bivariate and partial Pearson’s correlations were performed to evaluate the relation between diastolic BPV and executive function in women with a history of preeclampsia (N = 23; closed circles) and healthy controls (N = 38; open circles). R_p indicates partial correlation adjusted controlling for years of education, body mass index, and 24-hour average diastolic blood pressure.