Using an in-office passive leg raise to identify older adults with suboptimal blood pressure control

INTRODUCTION

Passive leg raise (PLR) is a simple, dynamic maneuver that has been used to increase preload to the heart. We hypothesize that PLR may offer a new and efficient office-based tool for assessing blood pressure (BP) control in older adults.

METHODS

One hundred and three veterans (≥60 years old) without known cardiovascular disease and varying degrees of blood pressure control were included in this cross-sectional cohort study. Twenty-four hour ambulatory BP monitoring identified Veterans with optimal and suboptimal BP control (≥125/75 mmHg). Bioimpedance electrodes (Baxter Medical, Deerfield, Illinois, USA) and brachial BP were used to calculate hemodynamic parameter changes across PLR states [pre-PLR, active PLR (3 min), and post-PLR]. Multiple linear regression was used to assess associations between BP control status with changes in hemodynamic parameters between PLR states.

RESULTS

The 24-h ambulatory BP monitoring identified 43 (42%) older Veterans with optimal BP control (mean age of 70.5 ± 7.0 years) and 55 (54%) with suboptimal BP (mean age of 71.3 ± 8.7 years). Veterans with suboptimal BP control had significantly reduced change in total peripheral resistance (ΔTPR) (7.0 ± 156.0 vs. 127.3 ± 145.6 dynes s/cm5; P = 0.002) following PLR compared with Veterans with optimal BP control. Suboptimal BP control (β = -0.35, P = 0.004) had a significant association with reduced ΔTPR, even after adjusting for demographic variables.

CONCLUSION

Measuring PLR-induced hemodynamic changes in the office setting may represent an alternative way to identify older adults with suboptimal BP control when 24-h ambulatory BP monitoring is not available.

Impact of body mass index on long-term blood pressure variability: a cross-sectional study in a cohort of Chinese adults

BACKGROUND

Obesity and overweight are related to changes in blood pressure, but existing research has mainly focused on the impact of body mass index (BMI) on short-term blood pressure variability (BPV). The study aimed to examine the impact of BMI on long-term BPV.

METHODS

Participants in the Kailuan study who attended all five annual physical examinations in 2006, 2008, 2010, 2012, and 2014 were selected as observation subjects. In total, 32,482 cases were included in the statistical analysis. According to the definition of obesity in China, BMI was divided into four groups: underweight (BMI < 18.5 kg/m²), normal weight (18.5 ≤ BMI < 24.0 kg/m²), overweight (24.0 ≤ BMI < 28.0 kg/m²), and obese (BMI ≥ 28.0 kg/m²). We used average real variability to evaluate long-term systolic BPV. The average real variability of systolic blood pressure (ARV_SBP) was calculated as (|sbp2 - sbp1| + |sbp3 - sbp2 | + |sbp4 - sbp3| + |sbp5 - sbp4|)/4. Differences in ARV_SBP by BMI group were analyzed using analysis of variance. Stepwise multivariate linear regression and multiple logistic regression analyses were used to assess the impact of BMI on ARV_SBP.

RESULTS

Participants' average age was 46.6 ± 11.3 years, 24,502 were men, and 7980 were women. As BMI increases, the mean value of ARVSBP gradually increases. After adjusting for other confounding factors, stepwise multivariate linear regression analysis showed that ARVSBP increased by 0.077 for every one-unit increase in BMI. Multiple logistic regression analysis indicated that being obese or overweight, compared with being normal-weight, were risk factors for an increase in ARVSBP. The corresponding odds ratios of being obese or overweight were 1.23 (1.15-1.37) and 1.10 (1.04-1.15), respectively.

CONCLUSIONS

There was a positive correlation between BMI and ARVSBP, with ARVSBP increasing with a rise in BMI. BMI is a risk factor for an increase in ARVSBP.

TRIAL REGISTRATION

Registration No.: CHiCTR-TNC1100 1489 ; Registration Date: June 01, 2006.

Assessment and management of blood-pressure variability

Blood pressure (BP) is characterized by marked short-term fluctuations occurring within a 24 h period (beat-to-beat, minute-to-minute, hour-to-hour, and day-to-night changes) and also by long-term fluctuations occurring over more-prolonged periods of time (days, weeks, months, seasons, and even years). Rather than representing 'background noise' or a randomly occurring phenomenon, these variations have been shown to be the result of complex interactions between extrinsic environmental and behavioural factors and intrinsic cardiovascular regulatory mechanisms. Although the adverse cardiovascular consequences of hypertension largely depend on absolute BP values, evidence from observational studies and post-hoc analyses of data from clinical trials have indicated that these outcomes might also depend on increased BP variability (BPV). Increased short-term and long-term BPV are associated with the development, progression, and severity of cardiac, vascular, and renal damage and with an increased risk of cardiovascular events and mortality. Of particular interest are the findings from post-hoc analyses of large intervention trials in hypertension, showing that within-patient visit-to-visit BPV is strongly prognostic for cardiovascular morbidity and mortality. This result has prompted discussion on whether antihypertensive treatment should be targeted not only towards reducing mean BP levels but also to stabilizing BPV with the aim of achieving consistent BP control over time, which might favour cardiovascular protection.

Arterial stiffness is related to augmented seasonal variation of blood pressure in hypertensive patients

BACKGROUND

Seasonal variation in blood pressure (BP), a usual tendency of both systolic (SBP) and diastolic BP (DBP) to rise during winter in hypertensive patients, may be related to the higher cardiovascular mortality in winter. However, it is not yet clear what factors are relevant to the seasonal BP changes. We hypothesized that arterial stiffness is related to the BP changes between summer and winter.

METHODS AND RESULTS

Eighty-five elderly (>55 years) patients with essential hypertension (33 males, 64+/-6.0 years) were enrolled. Seasonal BP profiles over at least 2 years were studied along with arterial stiffness and clinical variables (age, gender, smoking, duration of hypertension, anti-hypertensive medications and body mass index). Both SBP and DBP were significantly higher during winter compared with three other seasons (spring 128+/-10.0/79+/-7.3 mmHg, summer 127+/-9.8/78+/-7.1 mmHg, autumn 127+/-10.3/78+/-8.0 mmHg, winter 136+/-12.5/81+/-7.6 mmHg; SBP changes; p<0.001, DBP changes; p<0.001). There were no significant seasonal differences among spring, summer and autumn. Pulse wave velocity (PWV), a widely used clinical indicator of arterial stiffness was correlated with winter-summer differences in SBP (r = 0.272, p = 0.012), but not in DBP (r = 0.188, p = 0.085). Age, which was correlated with PWV strongly (p<0.001), was not significantly related to the seasonal changes in BP (SBP changes; p = 0.114, DBP changes; p = 0.298). No other clinical variables had significant correlation with seasonal BP changes. Multivariate regression analysis revealed that PWV is the only significant predictor for winter-summer SBP changes.

CONCLUSIONS

Our results established a feasible link between arterial stiffness and seasonal BP variation. These findings may partly explain higher cardiovascular risk in patients with increased arterial stiffness.

Superiority of ambulatory to physician blood pressure is not an artifact of differential measurement reliability

BACKGROUND

Ambulatory blood pressure is a better predictor of target organ damage and the risk of adverse cardiovascular events than office measurements. Whether this is due to the greater reliability owing to the larger number of measurements that are usually taken using ambulatory monitoring, or the greater validity of these measurements independent of the number, remains controversial.

METHODS

We addressed this issue by comparing physician readings and ambulatory measurements as predictors of left ventricular mass index. The number of readings was controlled by using the average of three physician readings and randomly selecting three awake readings from a 24-h ambulatory recording.

RESULTS

In a multiple regression analysis that included both the ambulatory and physician blood pressure measurements, only the ambulatory systolic measurements significantly predicted left ventricular mass index (B=0.37, t=3.11, P=0.002); the coefficient for physician's systolic measurements was essentially zero (B=-0.01, t=-0.26, NS).

CONCLUSIONS

These findings suggest that the superiority of ambulatory blood pressure as a predictor of target organ damage, compared with physician measurements, cannot be adequately/fully explained by the impact of the larger number of measurements obtained with ambulatory monitoring.