1. |
- Asayama, Kei, et al.
(author)
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Setting Thresholds to Varying Blood Pressure Monitoring Intervals Differentially Affects Risk Estimates Associated With White-Coat and Masked Hypertension in the Population
- 2014
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In: Hypertension. - 0194-911X .- 1524-4563. ; 64:5, s. 935-942
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Journal article (peer-reviewed)abstract
- Outcome-driven recommendations about time intervals during which ambulatory blood pressure should be measured to diagnose white-coat or masked hypertension are lacking. We cross-classified 8237 untreated participants (mean age, 50.7 years; 48.4% women) enrolled in 12 population studies, using >= 140/>= 90, >= 130/>= 80, >= 135/>= 85, and >= 120/>= 70 mm Hg as hypertension thresholds for conventional, 24-hour, daytime, and nighttime blood pressure. White-coat hypertension was hypertension on conventional measurement with ambulatory normotension, the opposite condition being masked hypertension. Intervals used for classification of participants were daytime, nighttime, and 24 hours, first considered separately, and next combined as 24 hours plus daytime or plus nighttime, or plus both. Depending on time intervals chosen, white-coat and masked hypertension frequencies ranged from 6.3% to 12.5% and from 9.7% to 19.6%, respectively. During 91 046 person-years, 729 participants experienced a cardiovascular event. In multivariable analyses with normotension during all intervals of the day as reference, hazard ratios associated with white-coat hypertension progressively weakened considering daytime only (1.38; P=0.033), nighttime only (1.43; P=0.0074), 24 hours only (1.21; P=0.20), 24 hours plus daytime (1.24; P=0.18), 24 hours plus nighttime (1.15; P=0.39), and 24 hours plus daytime and nighttime (1.16; P=0.41). The hazard ratios comparing masked hypertension with normotension were all significant (P<0.0001), ranging from 1.76 to 2.03. In conclusion, identification of truly low-risk white-coat hypertension requires setting thresholds simultaneously to 24 hours, daytime, and nighttime blood pressure. Although any time interval suffices to diagnose masked hypertension, as proposed in current guidelines, full 24-hour recordings remain standard in clinical practice.
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2. |
- Boggia, Jose, et al.
(author)
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Ambulatory Blood Pressure Monitoring in 9357 Subjects From 11 Populations Highlights Missed Opportunities for Cardiovascular Prevention in Women
- 2011
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In: Hypertension. - 0194-911X .- 1524-4563. ; 57:3, s. 397-405
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Journal article (peer-reviewed)abstract
- To analyze sex-specific relative and absolute risks associated with blood pressure (BP), we performed conventional and 24-hour ambulatory BP measurements in 9357 subjects (mean age, 52.8 years; 47% women) recruited from 11 populations. We computed standardized multivariable-adjusted hazard ratios for associations between outcome and systolic BP. During a course of 11.2 years (median), 1245 participants died, 472 of cardiovascular causes. The number of fatal combined with nonfatal events was 1080, 525, and 458 for cardiovascular and cardiac events and for stroke, respectively. In women and men alike, systolic BP predicted outcome, irrespective of the type of BP measurement. Women compared with men were at lower risk (hazard ratios for death and all cardiovascular events=0.66 and 0.62, respectively; P<0.001). However, the relation of all cardiovascular events with 24-hour BP (P=0.020) and the relations of total mortality (P=0.023) and all cardiovascular (P=0.0013), cerebrovascular (P=0.045), and cardiac (P=0.034) events with nighttime BP were steeper in women than in men. Consequently, per a 1-SD decrease, the proportion of potentially preventable events was higher in women than in men for all cardiovascular events (35.9% vs 24.2%) in relation to 24-hour systolic BP (1-SD, 13.4 mm Hg) and for all-cause mortality (23.1% vs 12.3%) and cardiovascular (35.1% vs 19.4%), cerebrovascular (38.3% vs 25.9%), and cardiac (31.0% vs 16.0%) events in relation to systolic nighttime BP (1-SD, 14.1 mm Hg). In conclusion, although absolute risks associated with systolic BP were lower in women than men, our results reveal a vast and largely unused potential for cardiovascular prevention by BP-lowering treatment in women.
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3. |
- Conen, David, et al.
(author)
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Age-Specific Differences Between Conventional and Ambulatory Daytime Blood Pressure Values
- 2014
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In: Hypertension. - 0194-911X .- 1524-4563. ; 64:5, s. 1073-1079
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Journal article (peer-reviewed)abstract
- Mean daytime ambulatory blood pressure (BP) values are considered to be lower than conventional BP values, but data on this relation among younger individuals <50 years are scarce. Conventional and 24-hour ambulatory BP were measured in 9550 individuals not taking antihypertensive treatment from 13 population-based cohorts. We compared individual differences between daytime ambulatory and conventional BP according to 10-year age categories. Age-specific prevalences of white coat and masked hypertension were calculated. Among individuals aged 18 to 30, 30 to 40, and 40 to 50 years, mean daytime BP was significantly higher than the corresponding conventional BP (6.0, 5.2, and 4.7 mm Hg for systolic; 2.5, 2.7, and 1.7 mm Hg for diastolic BP; all P<0.0001). In individuals aged 60 to 70 and >= 70 years, conventional BP was significantly higher than daytime ambulatory BP (5.0 and 13.0 mm Hg for systolic; 2.0 and 4.2 mm Hg for diastolic BP; all P<0.0001). The prevalence of white coat hypertension exponentially increased from 2.2% to 19.5% from those aged 18 to 30 years to those aged >= 70 years, with little variation between men and women (8.0% versus 6.1%; P=0.0003). Masked hypertension was more prevalent among men (21.1% versus 11.4%; P<0.0001). The age-specific prevalences of masked hypertension were 18.2%, 27.3%, 27.8%, 20.1%, 13.6%, and 10.2% among men and 9.0%, 9.9%, 12.2%, 11.9%, 14.7%, and 12.1% among women. In conclusion, this large collaborative analysis showed that the relation between daytime ambulatory and conventional BP strongly varies by age. These findings may have implications for diagnosing hypertension and its subtypes in clinical practice.
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4. |
- Gu, Yu-Mei, et al.
(author)
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Outcome-Driven Thresholds for Ambulatory Pulse Pressure in 9938 Participants Recruited From 11 Populations
- 2014
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In: Hypertension. - 0194-911X .- 1524-4563. ; 63:2, s. 229-237
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Journal article (peer-reviewed)abstract
- Evidence-based thresholds for risk stratification based on pulse pressure (PP) are currently unavailable. To derive outcome-driven thresholds for the 24-hour ambulatory PP, we analyzed 9938 participants randomly recruited from 11 populations (47.3% women). After age stratification (<60 versus >= 60 years) and using average risk as reference, we computed multivariable-adjusted hazard ratios (IIRs) to assess risk by tenths of the PP distribution or risk associated with stepwise increasing (+1 mm Hg) PP levels. All adjustments included mean arterial pressure. Among 6028 younger participants (68 853 person-years), the risk of cardiovascular (HR, 1.58; P=0.011) or cardiac (HR, 1.52; P=0.056) events increased only in the top PP tenth (mean, 60.6 mm Hg). Using stepwise increasing PP levels, the lower boundary of the 95% confidence interval of the successive thresholds did not cross unity. Among 3910 older participants (39 923 person-years), risk increased (P <= 0.028) in the top PP tenth (mean, 76.1 mm Hg). HRs were 1.30 and 1.62 for total and cardiovascular mortality, and 1.52, 1.69, and 1.40 for all cardiovascular, cardiac, and cerebrovascular events. The lower boundary of the 95% confidence interval of the HRs associated with stepwise increasing PP levels crossed unity at 64 mm Hg. While accounting for all covariables, the top tenth of PP contributed less than 0.3% (generalized R-2 statistic) to the overall risk among the elderly. Thus, in randomly recruited people, ambulatory PP does not add to risk stratification below age 60; in the elderly, PP is a weak risk factor with levels below 64 mm Hg probably being innocuous.
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5. |
- Li, Yan, et al.
(author)
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Ambulatory Hypertension Subtypes and 24-Hour Systolic and Diastolic Blood Pressure as Distinct Outcome Predictors in 8341 Untreated People Recruited From 12 Populations
- 2014
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In: Circulation. - 0009-7322 .- 1524-4539. ; 130:6, s. 466-474
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Journal article (peer-reviewed)abstract
- Background-Data on risk associated with 24-hour ambulatory diastolic (DBP24) versus systolic (SBP24) blood pressure are scarce. Methods and Results-We recorded 24-hour blood pressure and health outcomes in 8341 untreated people (mean age, 50.8 years; 46.6% women) randomly recruited from 12 populations. We computed hazard ratios (HRs) using multivariable-adjusted Cox regression. Over 11.2 years (median), 927 (11.1%) participants died, 356 (4.3%) from cardiovascular causes, and 744 (8.9%) experienced a fatal or nonfatal cardiovascular event. Isolated diastolic hypertension (DBP24 >= 80 mm Hg) did not increase the risk of total mortality, cardiovascular mortality, or stroke (HRs <= 1.54; P >= 0.18), but was associated with a higher risk of fatal combined with nonfatal cardiovascular, cardiac, or coronary events (HRs >= 1.75; P <= 0.0054). Isolated systolic hypertension (SBP24 >= 130 mm Hg) and mixed diastolic plus systolic hypertension were associated with increased risks of all aforementioned end points (P <= 0.0012). Below age 50, DBP24 was the main driver of risk, reaching significance for total (HR for 1-SD increase, 2.05; P=0.0039) and cardiovascular mortality (HR, 4.07; P=0.0032) and for all cardiovascular end points combined (HR, 1.74; P=0.039) with a nonsignificant contribution of SBP24 (HR <= 0.92; P >= 0.068); above age 50, SBP24 predicted all end points (HR >= 1.19; P <= 0.0002) with a nonsignificant contribution of DBP24 (0.96 <= HR <= 1.14; P >= 0.10). The interactions of age with SBP24 and DBP24 were significant for all cardiovascular and coronary events (P <= 0.043). Conclusions-The risks conferred by DBP24 and SBP24 are age dependent. DBP24 and isolated diastolic hypertension drive coronary complications below age 50, whereas above age 50 SBP24 and isolated systolic and mixed hypertension are the predominant risk factors.
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6. |
- Mena, Luis J., et al.
(author)
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How Many Measurements Are Needed to Estimate Blood Pressure Variability Without Loss of Prognostic Information?
- 2014
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In: American Journal of Hypertension. - : Oxford University Press (OUP). - 0895-7061 .- 1941-7225. ; 27:1, s. 46-55
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Journal article (peer-reviewed)abstract
- BACKGROUND Average real variability (ARV) is a recently proposed index for short-term blood pressure (BP) variability. We aimed to determine the minimum number of BP readings required to compute ARV without loss of prognostic information.METHODS ARV was calculated from a discovery dataset that included 24-hour ambulatory BP measurements for 1,254 residents (mean age 56.6 years; 43.5% women) of Copenhagen, Denmark. Concordance between ARV from full (80 BP readings) and randomly reduced 24-hour BP recordings was examined, as was prognostic accuracy. A test dataset that included 5,353 subjects (mean age 54.0 years; 45.6% women) with at least 48 BP measurements from 11 randomly recruited population cohorts was used to validate the results.RESULTS In the discovery dataset, a minimum of 48 BP readings allowed an accurate assessment of the association between cardiovascular risk and ARV. In the test dataset, over 10.2 years (median), 806 participants died (335 cardiovascular deaths, 206 cardiac deaths) and 696 experienced a major fatal or nonfatal cardiovascular event. Standardized multivariable-adjusted hazard ratios (HRs) were computed for associations between outcome and BP variability. Higher diastolic ARV in 24-hour ambulatory BP recordings predicted (P < 0.01) total (HR 1.12), cardiovascular (HR 1.19), and cardiac (HR 1.19) mortality and fatal combined with nonfatal cerebrovascular events (HR 1.16). Higher systolic ARV in 24-hour ambulatory BP recordings predicted (P < 0.01) total (HR 1.12), cardiovascular (HR 1.17), and cardiac (HR 1.24) mortality.CONCLUSIONS Forty-eight BP readings over 24 hours were observed to be adequate to compute ARV without meaningful loss of prognostic information.
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