Health Behaviors, Nocturnal Hypertension, and Non-dipping Blood Pressure: The Coronary Artery Risk Development in Young Adults and Jackson Heart Study

Are ambulatory blood pressure parameters associated more with central adiposity than with total adiposity? Results of the ELSA-Brasil study

Background

Worldwide obesity has a high prevalence, as well as carries a high risk of several chronic diseases, including hypertension. Studies of the association between obesity and ambulatory blood pressure (BP) are scarce and most use only body mass index (BMI) as indicator of adiposity. Thus, we aimed to examine for associations between total and central adiposity and ambulatory BP parameters (BP means and variability, nocturnal dipping and morning surge) among participants in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

Methods

This cross-sectional study (2012-2014) used a subsample of participants (n = 812) of ELSA-Brasil who underwent 24-hour ambulatory BP monitoring to assess systolic and diastolic BP (SBP and DBP, respectively) over 24-hour periods and sub-periods. Indicators for total adiposity were BMI and body fat (BF) and, for central adiposity, waist circumference (WC) and waist-to-height ratio (WHR). Associations were tested using crude and adjusted gamma and logistic regression.

Results

Overweight (BMI) and abdominal obesity (WC and WHR) associated positively with mean 24-hour (Coef = 2.71, 3.09 and 4.00, respectively), waking (Coef = 2.87, 3.26 and 4.16, respectively), and sleeping (Coef = 2.30, 2.74 and 3.50, respectively) SBP; mean DBP associated with high WHR in these three periods (Coef = 2.00, 2.10 and 1.68, respectively) and with WC in the waking period (Coef = 1.44). Overweight and abdominal obesity (WC and WHR) were positively associated with SBP variability over 24 h (Coef = 0.53, 0.45 and 0.49, respectively) and in sleep (Coef = 0.80, 0.74 and 0.59, respectively), and with DBP variability in 24 h (Coef = 0.64, 0.73 and 0.58, respectively), wakefulness (Coef = 0.50, 0.52 and 0.52, respectively) and sleep (Coef = 0.53, 0.45 and 0.49); excess BF associated positively with DBP variability over 24 h (Coef = 0.43) and in wakefulness (Coef = 0.38). Lastly, high WHR and excess BF were associated with higher odds of extreme dipping (OR = 1.03 for both), while high WC and WHR associated with higher odds of exacerbated diastolic morning surge (OR = 3.18 and 3.66, respectively).

Conclusion

Indicators of adiposity were associated with the BP means and variability, nocturnal dipping and morning surge, with more substantial results for indicators of central adiposity that the others.

Classification of blood pressure during sleep impacts designation of nocturnal nondipping

The identification of nocturnal nondipping blood pressure (< 10% drop in mean systolic blood pressure from awake to sleep periods), as captured by ambulatory blood pressure monitoring, is a valuable element of risk prediction for cardiovascular disease, independent of daytime or clinic blood pressure measurements. However, capturing measurements, including determination of wake/sleep periods, is challenging. Accordingly, we sought to evaluate the impact of different definitions and algorithms for defining sleep onset on the classification of nocturnal nondipping. Using approaches based upon participant self-reports, applied definition of a common sleep period (12 am -6 am), manual actigraphy, and automated actigraphy we identified changes to the classification of nocturnal nondipping, and conducted a secondary analysis on the potential impact of an ambulatory blood pressure monitor on sleep. Among 61 participants in the Eastern Caribbean Health Outcomes Research Network hypertension study with complete ambulatory blood pressure monitor and sleep data, the concordance for nocturnal nondipping across methods was 0.54 by Fleiss' Kappa (depending on the method, 36 to 51 participants classified as having nocturnal nondipping). Sleep quality for participants with dipping versus nondipping was significantly different for total sleep length when wearing the ambulatory blood pressure monitor (shorter sleep duration) versus not (longer sleep duration), although there were no differences in sleep efficiency or disturbances. These findings indicate that consideration of sleep time measurements is critical for interpreting ambulatory blood pressure. As technology advances to detect blood pressure and sleep patterns, further investigation is needed to determine which method should be used for diagnosis, treatment, and future cardiovascular risk.

Nocturnal blood pressure rise as a predictor of cognitive impairment among the elderly: a retrospective cohort study

Background

This study investigated the different blood pressure patterns that were evaluated by ambulatory blood pressure monitoring (ABPM) among elderly patients and explored the effect of pressure patterns on cognitive impairment and mortality.

Methods

A total of 305 elderly participants aged ≥65 years were divided into the cognitive impairment group (CI, n = 130) and the non-cognitive impairment group (NCI, n = 175) according to the MMSE score. All participants underwent ABPM to evaluate possible hypertensive disorder and cerebral MRI for the evaluation of cerebral small vessel disease. Follow-up was performed by telephone or medical records. The primary outcome was all-cause mortality. Secondary endpoints were major adverse cardiac and cerebrovascular events (MACCE).

Results

Among 305 participants, 130 (42.6%) were identified with cognitive impairment (CI), with average systolic blood pressure (BP) of 127 mmHg and diastolic BP of 66 mmHg. According to ABPM, only 13.1% had a dipper pattern, 45.6% had a nocturnal BP rise, while 41.3% had a non-dipper pattern. Compared with NCI patients, the CI group had significantly higher night-time systolic BP (130.0 ± 18.2 vs. 123.9 ± 15.1, p = 0.011), and more participants had nocturnal BP rise (52.3% vs. 40.6%, p = 0.042). Nocturnal BP rise was associated with greater white matter hyperintensities (WMH) (p = 0.013). After 2.03 years of follow-up, there were 35 all-cause deaths and 33 cases of major adverse cardiac and cerebrovascular events (MACCE). CI was independently associated with all-cause mortality during long-term observation (p < 0.01). Nocturnal BP rise had no significant predictive ability for all-cause mortality in elderly patients (p = 0.178).

Conclusions

Nocturnal BP rise contributed to greater cognitive impairment in elderly patients. Not nocturnal BP rise, but CI could significantly increase all-cause mortality. Controlling BP based on ABPM is critical for preventing the progression of cognitive dysfunction.

Team Science: American Heart Association's Hypertension Strategically Focused Research Network Experience

In 2015, the American Heart Association awarded 4-year funding for a Strategically Focused Research Network focused on hypertension composed of 4 Centers: Cincinnati Children's Hospital, Medical College of Wisconsin, University of Alabama at Birmingham, and University of Iowa. Each center proposed 3 integrated (basic, clinical, and population science) projects around a single area of focus relevant to hypertension. Along with scientific progress, the American Heart Association put a significant emphasis on training of next-generation hypertension researchers by sponsoring 3 postdoctoral fellows per center over 4 years. With the center projects being spread across the continuum of basic, clinical, and population sciences, postdoctoral fellows were expected to garner experience in various types of research methodologies. The American Heart Association also provided a number of leadership development opportunities for fellows and investigators in these centers. In addition, collaboration was highly encouraged among the centers (both within and outside the network) with the American Heart Association providing multiple opportunities for meeting and expanding associations. The area of focus for the Cincinnati Children's Hospital Center was hypertension and target organ damage in children utilizing ambulatory blood pressure measurements. The Medical College of Wisconsin Center focused on epigenetic modifications and their role in pathogenesis of hypertension using human and animal studies. The University of Alabama at Birmingham Center's areas of research were diurnal blood pressure patterns and clock genes. The University of Iowa Center evaluated copeptin as a possible early biomarker for preeclampsia and vascular endothelial function during pregnancy. In this review, challenges faced and successes achieved by the investigators of each of the centers are presented.

Influence of elevated sleep-time blood pressure on vascular risk and hypertension-mediated organ damage

We report the analysis of 252 hypertensive patients whose blood pressure (BP) was assessed by around-the-clock ambulatory BP monitoring compared to office BP measurement during a follow-up investigation of 8.7 y (SD: 2.43 y) that evaluated the added value of measuring sleep-time BP values. We found that 37.3% of the patients had mismatched diagnoses between the two techniques of BP assessment, with 11.5% of the patients showing white-coat hypertension and 25.8% masked hypertension. Only 12.3% of the diagnosed and treated patients presented normal BP values. Nocturnal (sleep-time) hypertension was present in 70.63%. The sleep-time systolic BP mean was found to be an independent vascular risk factor (F = 9.005, p < .001), indirectly measured through the 10-year risk of morbidity and mortality. Additionally, the elevated sleep-time systolic BP mean was a better marker of subclinical hypertension-mediated organ damage (ρ = 0.19, p < .01) than either the awake (ρ = 0.168, p < .01) or 24 (ρ = 0.184, p < .01) systolic BP means. In conclusion, the accuracy and sleep-time measurements provided by ambulatory BP make it particularly relevant in hypertension diagnosis and management. The use of the ambulatory BP measurement method could end up modifying current therapeutic targets, with sleep-time systolic BP mean becoming a main one, in order to optimize hypertension control and reduce hypertension-related organ pathology and cardiovascular disease morbidity and mortality.

Visceral fat, cardiometabolic risk factors, and nocturnal blood pressure fall in young adults with primary hypertension

The aims of this study were to assess associations of body fat levels and distribution with metabolic profiles and 24-hour blood pressure in young adults with primary hypertension. Visceral fat (VF) was estimated using dual-energy X-ray absorptiometry. VF was highly significantly associated with a high frequency of overweight/obesity, impaired fasting glucose, increased levels of triglycerides and LDL-cholesterol, and lowered level of HDL-cholesterol. The value of systolic blood pressure (SBP) nocturnal fall was similar between patients receiving RAAS inhibitors, beta-blockers, and calcium channel blockers. In multiple regression, the VF/weight ratio after adjusting for age, gender, total fat, and chronotherapeutic drug delivery was associated with the percentage SBP nocturnal fall (β = -.3108; 95% CI: -0.5923; -0.0980; P = .013). In males, excess VF increased the odds by 2.3 times for non-dipping blood pressure. Our results suggest that in young adult hypertensives, the VF/weight ratio might be associated with non-dipping blood pressure.

Clinical Significance and Therapeutic Implication of Nocturnal Hypertension: Relationship between Nighttime Blood Pressure and Quality of Sleep

Recent global hypertension guidelines recommend an early, strict and 24-hour blood pressure (BP) control for the prevention of target organ damage and cardiovascular events. Out-of-office BP measurement such as ambulatory BP monitoring and home BP monitoring is now widely utilized to rule out white-coat hypertension, to detect masked hypertension, to evaluate the effects of antihypertensive medication, to analyze diurnal BP variation, and to increase drug adherence. Nocturnal hypertension has been neglected in the management of hypertension despite of its clinical significance. Nighttime BP and non-dipping patterns of BP are stronger risk predictors for the future cardiovascular mortality and morbidity than clinic or daytime BP. In addition to ambulatory or home daytime BP and 24-hour mean BP, nocturnal BP should be a new therapeutic target for the optimal treatment of hypertension to improve prognosis in hypertensive patients. This review will provide an overview of epidemiology, characteristics, and pathophysiology of nocturnal hypertension and clinical significance, therapeutic implication and future perspectives of nocturnal hypertension will be discussed.