Awake Blood Pressure Research Articles

Abstract P187: The Associations of White Coat and Masked Hypertension With Cardiovascular Disease and Mortality in the Jackson Heart Study

Introduction: The 2017 American College of Cardiology/American Heart Association (ACC/AHA) blood pressure (BP) guideline uses lower clinic and out-of-clinic BP thresholds to define hypertension compared to previous US guidelines. Using these thresholds, we determined the associations between white coat hypertension (WCH) and masked hypertension with cardiovascular disease (CVD) events and mortality. Methods: We included 993 African Americans participating in the Jackson Heart Study who had clinic BP measured during their baseline study visit between 2000 and 2004 and underwent ambulatory blood pressure monitoring (ABPM). We defined normotension, WCH/white coat effect (WCE), masked/masked uncontrolled hypertension, and sustained hypertension using clinic BP and mean awake BP on ABPM (Table). CVD events (i.e., coronary heart disease and stroke; n=107), and all-cause mortality (n=185) were adjudicated from baseline through December 2014 and December 2016, respectively. Results: The mean age of participants was 59 years and 68% were female. Among those not taking antihypertensive medication, 38% had normotension, 27% had WCH, 33% had masked hypertension, and 31% had sustained hypertension. WCH, masked hypertension, and sustained hypertension were each associated with an increased risk for CVD and mortality compared to normotension (Table). Among those taking antihypertensive medication, 26% had controlled normotension, 25% had a WCE, 45% had masked uncontrolled hypertension, and 39% had treated sustained hypertension. Masked uncontrolled hypertension was associated with a higher risk for CVD and a lower risk for mortality compared to controlled normotension. WCE was not associated with CVD events or all-cause mortality. Conclusions: According to the ACC/AHA BP guideline, WCH and masked hypertension are common among African American adults. ABPM could have an important role in guiding antihypertensive medication initiation and intensification to reduce CVD and mortality risk among African Americans.

Comparing Automated Office Blood Pressure Readings With Other Methods of Blood Pressure Measurement for Identifying Patients With Possible Hypertension

ImportanceAutomated office blood pressure (AOBP) measurement involves recording several blood pressure (BP) readings using a fully automated oscillometric sphygmomanometer with the patient resting alone in a quiet place. Although several studies have shown AOBP measurement to be more accurate than routine office BP measurement and not subject to a “white coat effect,” the cumulative evidence has not yet been systematically reviewed.ObjectiveTo perform a systematic review and meta-analysis to examine the association between AOBP and office BP readings measured in routine clinical practice and in research studies, and ambulatory BP recorded during awake hours, as the latter is a standard for predicting future cardiovascular events.Data SourcesThe MEDLINE, Embase, and Cochrane Library were searched from 2003 to April 25, 2018.Study SelectionStudies on systolic and diastolic BP measurement by AOBP in comparison with awake ambulatory BP, routine office BP, and research BP measurements were included if they contained 30 patients or more.Data Extraction and SynthesisStudy characteristics were abstracted independently and random effects meta-analyses and meta-regressions were conducted.Main Outcomes and MeasuresPooled mean differences (95% CI) of systolic and diastolic BP between types of BP measurement.ResultsData were compiled from 31 articles comprising 9279 participants (4736 men and 4543 women). In samples with systolic AOBP of 130 mm Hg or more, routine office and research systolic BP readings were substantially higher than AOBP readings, with a pooled mean difference of 14.5 mm Hg (95% CI, 11.8-17.2 mm Hg; n = 9; I2 = 94.3%; P < .001) for routine office systolic BP readings and 7.0 mm Hg (95% CI, 4.9-9.1 mm Hg; n = 9; I2 = 85.7%; P < .001) for research systolic BP readings. Systolic awake ambulatory BP and AOBP readings were similar, with a pooled mean difference of 0.3 mm Hg (95% CI, −1.1 to 1.7 mm Hg; n = 19; I2 = 90%; P < .001).Conclusions and RelevanceAutomated office blood pressure readings, only when recorded properly with the patient sitting alone in a quiet place, are more accurate than office BP readings in routine clinical practice and are similar to awake ambulatory BP readings, with mean AOBP being devoid of any white coat effect. There has been some reluctance among physicians to adopt this technique because of uncertainty about its advantages compared with more traditional methods of recording BP during an office visit. Based on the evidence, AOBP should now be the preferred method for recording BP in routine clinical practice.

Shift work of nursing professionals and blood pressure, burnout and common mental disorders

To analyze the influence of shift work on blood pressure, the presence of burnout and common mental disorders in nursing professionals. A cross-sectional study. Burnout was assessed by the Maslach Burnout Inventory, and Common Mental Disorders by the Self-Reporting Questionnaire. Casual blood pressure measurement and Ambulatory Blood Pressure Monitoring (ABPM) were performed. 231 professionals participated. The majority (59.7%) worked in shifts, and this condition was associated (p≤0.05) with: higher weekly workload; doing the night shift; shorter training and work time at the institution; alcoholism; leisure activity; and alteration in ambulatory blood pressure monitoring of the sleep period. The professionals with common mental disorders and who worked in shifts had lower casual diastolic pressure levels (p = 0.039) and higher hypertension prevalence (p = 0.045). The presence of emotional exhaustion was associated with normal waking blood pressure and depersonalization with altered sleep blood pressure. Shift work was associated with a higher prevalence of work-related negative factors, inadequate habits and lifestyles, and change in sleep blood pressure.

A9728 Comparison of awake home blood pressure using evening measurements to measurement done before bedtime in Malaysian hypertensive patients

Objectives: Studies have reported that home blood pressure (HBP) is a better predictor of cardiovascular mortality and morbidity than office blood pressure (BP). Guidelines recommend averaging the morning and evening HBP measurements to derive the mean awake BP. However recommendation in guidelines regarding the timing of evening HBP measurements is not consistent. Furthermore it is not convenient for most patients to measure the evening HBP before dinner. Hence this study aimed to compare the mean awake HBP when done in the morning and evening to HBP done in the morning and before going to bed. Methods: This is a cross-sectional study of 306 hypertensive patients in a primary care setting in Malaysia. A convenience sampling method was used to recruit patients. Patients were educated according to the standard guidelines on how to measure HBP using a validated oscillometric BP device. Two consecutive BP measurements were taken three times a day (morning, evening before dinner and at bedtime) for seven days. After excluding the measurements of the first day, the remaining measurements were used to derive the mean awake BP. Paired t-test was used for analysis. Results: The mean age of the population was 67 ± 10 years, 46.6% were males. The mean morning HBP was 129.5 mm ± 15 mmHg; mean evening BP taken before dinner was 126.9 ± 14.3 mmHg and bedtime 125.7 ± 15.9mmHg. The mean awake BP using morning and evening was 128.0 mmHg compared with 127.5 mmHg based on morning and bedtime readings, a difference of 0.5 mmHg (p = 0.13). Conclusion: There is no difference in awake HBP whether it is measured in the evening or before bedtime. For convenience of the patients, it would appear to be acceptable the HBP to be done before bed instead of the recommended time of evening before dinner.

The effect of birth season on diurnal variation of blood pressure in hypertensive patients

Background. Birth season has been found to be related to cardiovascular disorders, but the underlying mechanisms are unclear. The aim of this study was to evaluate the relationship between birth season and diurnal variation in blood pressure (BP) parameters in hypertensive patients. Material and methods. We enrolled 194 patients. The date of birth was recorded with the season of birth determined as winter (December-February), spring (March-May), summer (June-August) or autumn (September-November). All patients underwent 24-hour ambulatory blood pressure monitoring (ABPM) for evaluation of dipper or non-dipper status. We searched for the relationship between birth season and non-dipper status and other ABPM parameters. Results. 93 patients were classified into the dipper hypertensive group and 101 patients were in the non-dipper hypertensive group. We did not find any association between non-dipper status and birth season in hypertensive patients (p = 0.517). However, we found a significant relationship between diurnal variation in BP and birth season. This difference was observed between winter and spring season. We found a significant relationship between birth season and 24-hour diastolic BP, awake diastolic BP, sleep diastolic BP and sleep mean BP (p = 0.035, p = 0.037, p = 0.036, p = 0.032, respectively). These ABPM parameters were lower in patients born in winter than in those born in spring. Conclusion. Birth season was found to be related to diurnal variation in blood pressure in hypertensive patients. Hypertensive individuals born in winter had lower blood pressure than those born in spring.

Abstract P361: Single Pill Combination Therapy is Not Superior to Free Combination Therapy for Controlling Hypertension

Introduction: The 2017 AHA guidelines advocate the use of ambulatory blood pressure monitoring (ABPM) for assessing the response to anti-hypertensive therapy and favor the use of single pill combination therapy for patients on multiple drugs. We aimed to investigate whether single pill combination therapy was superior to free pill combination therapy for attainment of goal blood pressure. Methods: We used data from 1074 consecutive ABPM studies performed between February 2017 and March 2018 to identify patients who received the following drug combinations as either single pill or free pills: ACEI/HCTZ, ARB/HCTZ, ACEI/CCB, ARB/CCB. Goal blood pressure was defined as an average awake blood pressure below 130/80 mmHg. Results: There were 193 patients in the single pill combination group and 136 patients in the free pill combination group. There was no difference between the groups regarding age, gender, number of antihypertensive drugs, and previous cardiovascular disease except for previous stroke which was more common in the free pill combination group. Compared to single pill combination, free pill combination showed a trend to superiority in the rate of blood pressure control in all drug combinations, with statistical significance reached only when comparing pooled groups (see table). Conclusions: Single pill combination therapy was not superior to free pill combination therapy for attainment of goal blood pressure.

Asleep blood pressure: significant prognostic marker of vascular risk and therapeutic target for prevention.

Sleep-time blood pressure (BP) is a stronger risk factor for cardiovascular disease (CVD) events than awake and 24 h BP means, but the potential role of asleep BP as therapeutic target for diminishing CVD risk is uncertain. We investigated whether CVD risk reduction is most associated with progressive decrease of either office or ambulatory awake or asleep BP mean. We prospectively evaluated 18078 individuals with baseline ambulatory BP ranging from normotension to hypertension. At inclusion and at scheduled visits (mainly annually) during follow-up, ambulatory BP was measured for 48 consecutive hours. During the 5.1-year median follow-up, 2311 individuals had events, including 1209 experiencing the primary outcome (composite of CVD death, myocardial infarction, coronary revascularization, heart failure, and stroke). The asleep systolic blood pressure (SBP) mean was the most significant BP-derived risk factor for the primary outcome [hazard ratio 1.29 (95% CI) 1.22-1.35 per SD elevation, P < 0.001], regardless of office [1.03 (0.97-1.09), P = 0.32], and awake SBP [1.02 (0.94-1.10), P = 0.68]. Most important, the progressive attenuation of asleep SBP was the most significant marker of event-free survival [0.75 (95% CI 0.69-0.82) per SD decrease, P < 0.001], regardless of changes in office [1.07 (0.97-1.17), P = 0.18], or awake SBP mean [0.96 (0.85-1.08), P = 0.47] during follow-up. Asleep SBP is the most significant BP-derived risk factor for CVD events. Furthermore, treatment-induced decrease of asleep, but not awake SBP, a novel hypertension therapeutic target requiring periodic patient evaluation by ambulatory monitoring, is associated with significantly lower risk for CVD morbidity and mortality.

Office blood pressure measurement in the 21st century.

Measurement of blood pressure (BP) using the auscultatory method must follow specific rules and conditions to be reliable. Nonetheless, these requirements are often not followed in clinical practice, resulting in inaccurate BP readings. Simply replacing manual sphygmomanometers with an oscillometric device may still produce readings that are associated with a white coat effect. These limitations can be overcome by using an oscillometric sphygmomanometer that automatically records multiple readings with the patient resting quietly and alone, called automated office (AO)BP. AOBP produces office readings with a reduced white coat effect, which are also similar to the awake ambulatory BP. There is also evidence that AOBP is a better predictor of target organ damage than attended office BP. Furthermore, clinical outcome data support AOBP as having both a similar diagnostic threshold as awake ambulatory BP and a lower treatment target. Using AOBP in clinical practice simplifies recording office BP by not requiring an additional period of rest before activation of the device and by not having staff present during the actual measurements. Recent studies have reported that automatic BP measurements taken by staff in research studies with close adherence to guidelines using AOBP devices may produce similar readings to AOBP. Further research is needed to determine the best method for recording BP at systolic targets <130mm Hg and the relationship of office BP to ambulatory BP and home BP.

Antecedent rest may not be necessary for automated office blood pressure at lower treatment targets.

In SPRINT (Systolic Blood Pressure Intervention Trial), use of the Omron 907XL blood pressure (BP) monitor set at 5minutes of antecedent rest to record BP produced an automated office BP value 7/6mmHg lower than awake ambulatory BP at 27months. The authors studied the impact on automated office BP of setting the Omron 907XL to 0minutes instead of 5minutes of rest in patients with readings in the lower normal BP range, similar to on-treatment BP in the SPRINT intensive therapy group. Patients (n=100) in cardiac rehabilitation were randomized to three BP readings at 1-minute intervals using an Omron 907XL BP device set for 5 or 0minutes of antecedent rest. Mean (±standard deviation) automated office BP (mmHg) after 5minutes of rest (120.2±14.6/66.9±8.6 mm Hg) was lower (P<.001/P<.01) than without rest (124.2±16.4/67.9±9.1 mm Hg). When target BP is in the lower normal range, automated office BP recorded without antecedent rest using an Omron 907XL device should be higher and closer to the awake ambulatory BP, compared with readings taken after 5minutes of rest.

WAVE REFLECTION IS INVERSELY ASSOCIATED WITH THE DEVELOPMENT OF MYOCARDIAL HYPERTROPHY AMONG HYPERTENSIVE SUBJECTS

Objective: Wave reflection forms the basis of arterial input impedance and they offer valuable information on arterial stiffness. Thus, it has emerged as a strong, important marker of premature cardiovascular disease. Objective: To evaluate the association between wave reflection coefficient and the myocardial hypertrophy among hypertensive subjects. Design and method: Subjects with office blood pressure (BP) >140/90 mmHg, without treatment attending our Hypertension Center participated in the study. Exclusion criteria were renal dysfunction, heart failure, severe arrhythmia including atrial fibrillation and evidence of secondary hypertension. A complete medical history was obtained from all participants. Office BP was measured in 3 consecutive visits (Microlife WatchBPN, Microlife, Widnau, Switzerland). Consequently, all participants underwent 24 h ambulatory blood pressure monitoring (24h-ABPM), using the Mobil-O-Graph monitor (IEM, Stolberg, Germany). Mobil-O-Graph records oscillometric brachial BP, and calculates pulse wave velocity (PWV), aortic BP, augmentation index (Aix) and wave reflection as measure of arterial stiffness. BP measurements were performed at 20-min intervals for 24 hour. Daytime and nighttime periods were defined according to the patients’ diaries (awake and asleep periods). Transthoracic echocardiogram for the assessment of myocardial hypertrophy was performed in all subjects. Results are expressed as frequencies and percentages for qualitative variables and as mean values with SD for quantitative variables. Statistical analysis was performed using the Student's t-test for independent samples. A p-value of 0.05 was considered statistically significant. Results: A total of 72 individuals, mean age 52.15 ± 11.97 years, 31 women were included in the analysis. A strong inversed association between wave reflection coefficient and myocardial hypertrophy was observed, with p values <0.002. Similar association were found for 24-hour, awake and asleep BP (p = 0.002, p = 0.018 and p = 0.002, respectively). Conclusions: Wave reflections markedly affect the central pressure profile, further contributing to increased cardiovascular risk. Future studies should assess the role of genetic versus geographic and other environmental influences in wave reflection coefficient as an index of vascular remodeling and especially aortic stiffness.

Left ventricular remodeling and arterial afterload in older women with uncontrolled and controlled hypertension.

The prevalence of hypertension increases with advancing age in women. Blood pressure control is more difficult to achieve in older women, and despite well-controlled blood pressure, the cardiovascular mortality remains high. However, the underlying mechanisms are not understood. Nineteen women with uncontrolled hypertension on drug treatment (70 ± 2 [SE] years, ambulatory awake blood pressure; 152 ± 2/84 ± 2 mm Hg), 19 with controlled hypertension (68 ± 1 years, 128 ± 2/71 ± 2 mm Hg), and 31 healthy normotensive women (68 ± 1 years, 127 ± 1/73 ± 1 mm Hg) were recruited. Participants were weaned from antihypertensive drugs and underwent 3 weeks of run-in before cardiac-vascular assessments. Left ventricular morphology was evaluated with cardiac magnetic resonance imaging. Arterial load and vascular stiffness were measured via ultrasound and applanation tonometry. Left ventricular mass normalized by body surface area was not different between hypertension groups (uncontrolled vs controlled: 50.0 ± 1.7 vs 51.8 ± 2.3 g/m), but it was lower in the normotensive group (41.7 ± 0.9 g/m; one-way analysis of variance [ANOVA] P = 0.004). Likewise, central pulse wave velocity was not different between hypertension groups (11.5 ± 0.6 vs 11.1 ± 0.5 m/s) and lower in the normotensive group (9.1 ± 0.3 m/s; 1-way ANOVA P = 0.0001). Total peripheral resistance was greater in uncontrolled hypertension (HTN) compared with normotensive group (2051 ± 323 vs 1719 ± 380 dyns/cm), whereas controlled HTN group (1925 ± 527 dyns/cm) was not different to either groups. Regardless of current blood pressure control, hypertensive older women exhibited increased cardiac mass and arterial stiffness compared with normotensives. Future large-scale longitudinal studies are warranted to directly investigate the mechanisms for the high cardiovascular mortality among older hypertensive women with well-controlled blood pressure.

Nocturnal blood pressure fluctuation and associated influential factors in severe obstructive sleep apnea patients with hypertension

Obstructive sleep apnea syndrome (OSAS) can induce dramatic blood pressure (BP) fluctuations during sleep and it can be associated with hypertension. We investigated the properties and associated influential factors of BP fluctuation in severe OSAS with and without hypertension. Two hundred one severe OSAS subjects were divided into hypertensive and normotensive groups. BP was continuously monitored via measurement of pulse transmit time (PTT). The value of apnea-related systolic BP elevation (ΔSBP) was used to reflect the amplitude of BP fluctuation, and the SBP index (the number of ΔSBP > 10mmHg per hour of sleep time) was used to stand for the frequency of significant BP fluctuations. Compared with the normotensive group, △SBP and SBP index were higher in the hypertensive group (13.8 ± 4.4mmHg vs 10.9 ± 3.1mmHg; 44.8 ± 21.3 events/h vs 26.8 ± 15.8 events/h, all p < 0.001). Multiple regression analysis showed that percentage of sleep time with oxygen saturation < 90% (TST90) and SBP index correlated more with mean level of awakeness and sleep SBP than with apnea-hypopnea index (AHI). Analysis of all apnea events demonstrated that △SBP and the frequency of BP fluctuations were more remarkable following hypoxia than following arousal; △SBP correlated more with oxygen desaturation degree (r = 0.388, p < 0.01) and minimal SpO2 (r = 0.392, p < 0.01) than with apnea length and desaturation duration. In severe OSAS, nocturnal and awake BP levels are associated more with the nocturnal hypoxic duration and BP fluctuation than with AHI. Nocturnal BP fluctuation can be induced by both hypoxia and arousal, and especially by hypoxia. NCT02876471.

The relationship of age-adjusted Charlson comorbidity ındex and diurnal variation of blood pressure

ABSTRACTBackgrounds: Charlson Comorbidity index (CCI) is a scoring system to predict prognosis and mortality. It exhibits better utility when combined with age, age-adjusted Charlson Comorbidity Index (ACCI). The aim of this study was to evaluate the relationship between ACCI and diurnal variation of blood pressure parameters in hypertensive patients and normotensive patients.Methods: We enrolled 236 patients. All patients underwent a 24-h ambulatory blood pressure monitoring (ABPM) for evaluation of dipper or non-dipper pattern. We searched the correlation between ACCI and dipper or non-dipper pattern and other ABPM parameters. To further investigate the role of these parameters in predicting survival, a multivariate analysis using the Cox proportional hazard model was performed.Results: 167 patients were in the hypertensive group (87 patients in non-dipper status) and 69 patients were in the normotensive group (41 patients in non-dipper status) of all study patients. We found a significant difference and negative correlation between AACI and 24-h diastolic blood pressure (DBP), awake DBP, awake mean blood pressure (MBP) and 24-h MBP and awake systolic blood pressure(SBP). Night decrease ratio of blood pressure had also a negative correlation with ACCI (p = 0.003, r = −0.233). However, we found a relationship with non-dipper pattern and ACCI in the hypertensive patients (p = 0.050). In multivariate Cox analysis sleep MBP was found related to mortality like ACCI (p = 0.023, HR = 1.086, %95 CI 1.012–1.165)Conclusion: ACCI was statistically significantly higher in non-dipper hypertensive patients than dipper hypertensive patients while ACCI had a negative correlation with blood pressure. Sleep MBP may predict mortality.

Hypertension: New perspective on its definition and clinical management by bedtime therapy substantially reduces cardiovascular disease risk.

Diagnosis of hypertension-elevated blood pressure (BP) associated with increased cardiovascular disease (CVD) risk-and its management for decades have been based primarily on single time-of-day office BP measurements (OBPM) assumed representative of systolic (SBP) and diastolic BP (DBP) during the entire 24-hours span. Around-the-clock ambulatory blood pressure monitoring (ABPM), however, reveals BP undergoes 24-hours patterning characterized in normotensives and uncomplicated hypertensives by striking morning-time rise, 2daytime peaks-one ~2-3hours after awakening and the other early evening, small midafternoon nadir and 10-20% decline (BP dipping) in the asleep BP mean relative to the wake-time BP mean. A growing number of outcome trials substantiate correlation between BP and target organ damage, vascular and other risks is greater for the ABPM-derived asleep BP mean, independent and stronger predictor of CVD risk, than daytime OBPM or ABPM-derived awake BP. Additionally, bedtime hypertension chronotherapy, that is, ingestion of ≥1 conventional hypertension medications at bedtime to achieve efficient attenuation of asleep BP, better reduces total CVD events by 61% and major events (CVD death, myocardial infarction, ischaemic and haemorrhagic stroke) by 67%-even in more vulnerable chronic kidney disease, diabetes and resistant hypertension patients-than customary on-awaking therapy that targets wake-time BP. Such findings of around-the-clock ABPM and bedtime hypertension outcome trials, consistently indicating greater importance of asleep BP than daytime OBPM or ambulatory awake BP, call for a new definition of true arterial hypertension plus modern approaches for its diagnosis and management.

Carotid atherosclerosis and the association between nocturnal blood pressure dipping and cardiovascular events

The impact of a nondipping blood pressure (BP) pattern, defined as (awake systolic BP - sleep systolic BP)/awake systolic BP<0.1, on cardiovascular events in populations with different degrees of carotid atherosclerosis is uncertain. The authors hypothesized that a nondipping BP pattern would show differential predictive power for cardiovascular events, including total cardiovascular death, sudden death, nonfatal cardiovascular events, and nonfatal stroke, between populations with and without carotid atherosclerosis. To test this hypothesis, the authors analyzed 493 patients (mean age 67.9years, 47.5% men) from the J-HOP (Japan Morning Surge-Home Blood Pressure) study for whom ambulatory BP monitoring and carotid intima-media thickness data were available. Twenty-nine cardiovascular events occurred during follow-up (1867 person-years). A nondipping BP pattern was independently associated with cardiovascular events in the population without carotid atherosclerosis, defined as carotid intima-media thickness <1.1mm after adjustment for other cardiovascular risk factors including age, sex, diabetes mellitus, chronic kidney disease, and 24-hour systolic BP (hazard ratio, 8.15; 95% confidence interval, 1.76-37.78 [P<.01]). This association was not found in the population with carotid intima-media thickness ≥1.1mm. Therefore, in the hypertensive population without carotid atherosclerosis, physicians should consider ambulatory BP monitoring to determine the nocturnal BP pattern as an alternative approach to assessing cardiovascular events.

Automated Office Blood Pressure Measurement.

Manual blood pressure (BP) recorded in routine clinical practice is relatively inaccurate and associated with higher readings compared to BP measured in research studies in accordance with standardized measurement guidelines. The increase in routine office BP is the result of several factors, especially the presence of office staff, which tends to make patients nervous and also allows for conversation to occur. With the disappearance of the mercury sphygmomanometer because of environmental concerns, there is greater use of oscillometric BP recorders, both in the office setting and elsewhere. Although oscillometric devices may reduce some aspects of observer BP measurement error in the clinical setting, they are still associated with higher BP readings, known as white coat hypertension (for diagnosis) or white coat effect (with treated hypertension). Now that fully automated sphygmomanometers are available which are capable of recording several readings with the patient resting quietly, there is no longer any need to have office staff present when BP is being recorded. Such readings are called automated office blood pressure (AOBP) and they are both more accurate than conventional manual office BP and not associated with the white coat phenomena. AOBP readings are also similar to the awake ambulatory BP and home BP, both of which are relatively good predictors of cardiovascular risk. The available evidence suggests that AOBP should now replace manual or electronic office BP readings when screening patients for hypertension and also after antihypertensive drug therapy is initiated.

Association of office and ambulatory blood pressure with blood lead in workers before occupational exposure

In view of decreasing lead exposure and guidelines endorsing ambulatory above office blood pressure (BP) measurement, we reassessed association of BP with blood lead (BL) in 236 newly employed men (mean age, 28.6 years) without previous lead exposure not treated for hypertension. Office BP was the mean of five auscultatory readings at one visit. Twenty-four-hour BP was recorded at 15- and 30-minute intervals during wakefulness and sleep. BL was determined by inductively coupled plasma mass spectrometry. Systolic/diastolic office BP averaged 120.0/80.7 mm Hg, and the 24-hour, awake, and asleep BP 125.5/73.6, 129.3/77.9, and 117.6/65.0 mm Hg, respectively. The geometric mean of blood lead was 4.5 μg/dL (interquartile range, 2.60–9.15 μg/dL). In multivariable-adjusted analyses, effect sizes associated with BL doubling were 0.79/0.87 mm Hg (P = .11/.043) for office BP and 0.29/−0.25, 0.60/−0.10, and −0.40/−0.43 mm Hg for 24-hour, awake, and asleep BP (P ≥ .33). Neither office nor 24-hour ambulatory hypertension was related to BL (P ≥ .14). A clinically relevant white coat effect (WCE; office minus awake BP, ≥20/≥10 mm Hg) was attributable to exceeding the systolic or diastolic threshold in 1 and 45 workers, respectively. With BL doubling, the systolic/diastolic WCE increased by 0.20/0.97 mm Hg (P = .57/.046). Accounting for the presence of a diastolic WCE, reduced the association size of office diastolic BP with BL to 0.39 mm Hg (95% confidence interval, −0.20 to 1.33; P = .15). In conclusion, a cross-sectional analysis of newly hired workers before lead exposure identified the WCE as confounder of the association between office BP and BL and did not reveal any association between ambulatory BP and BL.

The impact of sleep disordered breathing on cardiovascular health in overweight children

BackgroundUp to 50% of overweight/obese children have obstructive sleep apnea (OSA) compared to up to 6% of normal weight children. We compared cardiovascular variables between normal weight and overweight/obese children with and without OSA, and controls. MethodsSeventy-four referred children and 24 normal weight non-snoring controls (8–18 years) were recruited. Referred children were grouped according to their obstructive apnea hypopnea index (OAHI): OSA (>1 event/h) or primary snoring (PS ≤ 1 event/h) and whether they were normal weight (BMI z-score <1.04) or overweight/obese (BMI z-score ≥ 1.04). Wake blood pressure (BP), heart rate (HR), and pulse transit time (PTT, an inverse continuous surrogate measure of blood pressure) during sleep were recorded. ResultsWake BP was higher in the overweight/obese OSA group than in the control, normal weight PS, and overweight/obese PS groups (p < 0.05 for all). During sleep, BP, and HR were elevated in the overweight/obese OSA group compared to those in non-snoring controls (p < 0.05). More children who were overweight/obese had reduced BP and HR dipping from wake to sleep than normal weight children. The BMI z-score predicted HR and PTT when asleep and both age and BMI z-score predicted BP when awake. ConclusionThis study showed that BMI has both combined and independent effects on BP and HR in children with OSA. We have previously shown that treatment of OSA reduces BP and suggest that treatment of OSA in the growing number of overweight/obese children may improve cardiovascular outcomes.

ECG Voltage in Relation to Peripheral and Central Ambulatory Blood Pressure.

BACKGROUNDThe heart ejects in the central elastic arteries. No previous study in workers described the diurnal profile of central blood pressure (BP) or addressed the question whether electrocardiogram (ECG) indexes are more closely associated with central than peripheral BP.METHODSIn 177 men (mean age, 29.1 years), we compared the associations of ECG indexes with brachial and central ambulatory BP, measured over 24 hours by the validated oscillometric Mobil-O-Graph 24h PWA monitor.RESULTSFrom wakefulness to sleep, as documented by diaries, systolic/diastolic BP decreased by 11.7/13.1 mm Hg peripherally and 9.3/13.6 mm Hg centrally, whereas central pulse pressure (PP) increased by 4.3 mm Hg (P < 0.0001). Over 24 hours and the awake and asleep periods, the peripheral-minus-central differences in systolic/diastolic BPs averaged 11.8/–1.6, 12.7/–1.8, and 10.3/–1.2 mm Hg, respectively (P < 0.0001). Cornell voltage and index averaged 1.18 mV and 114.8 mV·ms. Per 1-SD increment in systolic/diastolic BP, the Cornell voltages were 0.104/0.086 mV and 0.082/0.105 mV higher in relation to brachial 24-hour and asleep BP and 0.088/0.90 mV and 0.087/0.107 mV higher in relation to central BP. The corresponding estimates for the Cornell indexes were 9.6/8.6 and 8.2/10.5 mV·ms peripherally and 8.6/8.9 and 8.8/10.7 mV·ms centrally. The regression slopes (P ≥ 0.067) and correlation coefficients (P ≥ 0.088) were similar for brachial and central BP. Associations of ECG measurements with awake BP and PP were not significant.CONCLUSIONSPeripheral and central BPs run in parallel throughout the day and are similarly associated with the Cornell voltage and index.

Abstract 131: Racial Differences in Nocturnal Hypertension and Non-dipping Blood Pressure: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

Risk factors for nocturnal hypertension are more common among blacks compared with whites. We hypothesized nocturnal hypertension and nocturnal non-dipping BP are more common among blacks compared with whites. We analyzed data for 781 participants of the population-based Coronary Artery Risk Development in Young Adults (CARDIA) study who completed ambulatory blood pressure (BP) monitoring (ABPM) in 2015-2016. Awake and sleep periods were defined using actigraphy and self-report. Nocturnal hypertension was defined as mean sleep systolic BP (SBP)/diastolic BP (DBP) ≥ 120/70 mm Hg. Non-dipping SBP and DBP, separately, were defined as a decline in mean sleep BP, relative to mean awake BP &lt; 10%. The mean age of participants was 54.7 years, 21.1% were white women, 38.5% were black women, 16.8% were white men and 23.6% were black men. The prevalence of nocturnal hypertension was 18.2% and 44.5% among white and black women, respectively, and 35.9% and 59.8% among white and black men, respectively. After multivariable adjustment, the prevalence of nocturnal hypertension was higher among black women, white men and black men, each compared with white women (Table). The prevalence of non-dipping SBP was 21.2% and 40.9% among white and black women, respectively, and 19.8% and 37.5% among white and black men, respectively. After multivariable adjustment, non-dipping SBP was more common among black women and black men compared with white women. There were no statistically significant differences in non-dipping DBP across race-gender after multivariable adjustment. Nocturnal hypertension and non-dipping SBP are more common among blacks compared with whites even after adjustment for mean BP.