Predicted Atherosclerotic Cardiovascular Disease Risk and Masked Hypertension Among Blacks in the Jackson Heart Study.

BACKGROUND: Among individuals without hypertension based on clinic blood pressure (BP), it is unclear who should be screened for masked hypertension, defined as having hypertension based on out-of-clinic BP. We hypothesized that individuals with a higher 10-year predicted atherosclerotic cardiovascular disease (ASCVD) risk, calculated using the pooled cohort risk equations, have a higher prevalence of masked hypertension. METHODS AND RESULTS: We analyzed data from the Jackson Heart Study-a population-based cohort of blacks-to determine the association of predicted ASCVD risk with masked hypertension. The sample included 644 participants, 40 to 79 years of age, with clinic systolic/diastolic BP <140/90 mm Hg, who completed ambulatory BP monitoring, were free of cardiovascular disease, and had data on factors needed to calculate ASCVD risk. Ten-year predicted ASCVD risk was calculated using the pooled cohort risk equations. Any masked hypertension was defined as masked daytime hypertension (mean daytime systolic/diastolic BP ≥135/85 mm Hg), masked nighttime hypertension (mean nighttime systolic/diastolic BP ≥120/70 mm Hg), or masked 24-hour hypertension (mean 24-hour systolic/diastolic BP ≥130/80 mm Hg). The prevalence of any masked hypertension was 54.0%. Compared with participants in the lowest (<5%) predicted ASCVD risk category, multivariable-adjusted prevalence ratios (95% confidence interval) for any masked hypertension were 1.36 (1.03-1.79), 1.62 (1.22-2.16), and 1.91 (1.47-2.48) for those with ASCVD risk of 5% to <7.5%, 7.5% to <10%, and ≥10%, respectively. The C statistic for discriminating between participants with versus without any masked hypertension was 0.681 (95% confidence interval, 0.640-0.723) for ASCVD risk and 0.703 (95% confidence interval, 0.663-0.744) for clinic systolic BP and diastolic BP. CONCLUSIONS: Higher ASCVD risk was associated with an increased prevalence of masked hypertension. Although the discrimination of ASCVD risk for masked hypertension was not superior to clinic BP, risk prediction equations may be useful for identifying the subgroup of individuals with both masked hypertension and high predicted ASCVD risk.

Prevalence of Masked Hypertension Among US Adults With Nonelevated Clinic Blood Pressure.

Masked hypertension (MHT), defined as nonelevated blood pressure (BP) in the clinic setting and elevated BP assessed by ambulatory monitoring, is associated with increased risk of target organ damage, cardiovascular disease, and mortality. Currently, no estimate of MHT prevalence exists for the general US population. After pooling data from the Masked Hypertension Study (n = 811), a cross-sectional clinical investigation of systematic differences between clinic BP and ambulatory BP (ABP) in a community sample of employed adults in the New York City metropolitan area (2005-2012), and the National Health and Nutrition Examination Survey (NHANES; 2005-2010; n = 9,316), an ongoing nationally representative US survey, we used multiple imputation to impute ABP-defined hypertension status for NHANES participants and estimate MHT prevalence among the 139 million US adults with nonelevated clinic BP, no history of overt cardiovascular disease, and no use of antihypertensive medication. The estimated US prevalence of MHT in 2005-2010 was 12.3% of the adult population (95% confidence interval: 10.0, 14.5)-approximately 17.1 million persons aged ≥21 years. Consistent with prior research, estimated MHT prevalence was higher among older persons, males, and those with prehypertension or diabetes. To our knowledge, this study provides the first estimate of US MHT prevalence-nearly 1 in 8 adults with nonelevated clinic BP-and suggests that millions of US adults may be misclassified as not having hypertension.

Clinic Blood Pressure Underestimates Ambulatory Blood Pressure in an Untreated Employer-Based US Population: Results From the Masked Hypertension Study.

BACKGROUND: Ambulatory blood pressure (ABP) is consistently superior to clinic blood pressure (CBP) as a predictor of cardiovascular morbidity and mortality risk. A common perception is that ABP is usually lower than CBP. The relationship of the CBP minus ABP difference to age has not been examined in the United States. METHODS: Between 2005 and 2012, 888 healthy, employed, middle-aged (mean±SD age, 45±10.4 years) individuals (59% female, 7.4% black, 12% Hispanic) with screening BP <160/105 mm Hg and not taking antihypertensive medication completed 3 separate clinic BP assessments and a 24-hour ABP recording for the Masked Hypertension Study. The distributions of CBP, mean awake ABP (aABP), and the CBP-aABP difference in the full sample and by demographic characteristics were compared. Locally weighted scatterplot smoothing was used to model the relationship of the BP measures to age and body mass index. The prevalence of discrepancies in ABP- versus CBP-defined hypertension status-white-coat hypertension and masked hypertension-were also examined. RESULTS: Average systolic/diastolic aABP (123.0/77.4±10.3/7.4 mm Hg) was significantly higher than the average of 9 CBP readings over 3 visits (116.0/75.4±11.6/7.7 mm Hg). aABP exceeded CBP by >10 mm Hg much more frequently than CBP exceeded aABP. The difference (aABP>CBP) was most pronounced in young adults and those with normal body mass index. The systolic difference progressively diminished, but did not disappear, at older ages and higher body mass indexes. The diastolic difference vanished around age 65 and reversed (CBP>aABP) for body mass index >32.5 kg/m2. Whereas 5.3% of participants were hypertensive by CBP, 19.2% were hypertensive by aABP; 15.7% of those with nonelevated CBP had masked hypertension. CONCLUSIONS: Contrary to a widely held belief, based primarily on cohort studies of patients with elevated CBP, ABP is not usually lower than CBP, at least not among healthy, employed individuals. Furthermore, a substantial proportion of otherwise healthy individuals with nonelevated CBP have masked hypertension. Demonstrated CBP-aABP gradients, if confirmed in representative samples (eg, NHANES [National Health and Nutrition Examination Survey]), could provide guidance for primary care physicians as to when, for a given CBP, 24-hour ABP would be useful to identify or rule out masked hypertension.

Cardiovascular Risk Factors and Masked Hypertension: The Jackson Heart Study.

Masked hypertension is associated with increased risk for cardiovascular disease. Identifying modifiable risk factors for masked hypertension could provide approaches to reduce its prevalence. Life's Simple 7 is a measure of cardiovascular health developed by the American Heart Association that includes body mass index, physical activity, diet, cigarette smoking, blood pressure (BP), cholesterol, and glucose. We examined the association between cardiovascular health and masked daytime hypertension in the Jackson Heart Study, an exclusively African American cohort. Life's Simple 7 factors were assessed during a study visit and categorized as poor, intermediate, or ideal. Ambulatory BP monitoring was performed after the study visit. Using BP measured between 10:00 am and 8:00 pm on ambulatory BP monitoring, masked daytime hypertension was defined as mean clinic systolic BP/diastolic BP <140/90 mm Hg and mean daytime systolic BP/diastolic BP ≥135/85 mm Hg. Among the 758 participants with systolic BP/diastolic BP <140/90 mm Hg, 30.5% had masked daytime hypertension. The multivariable-adjusted prevalence ratios for masked daytime hypertension comparing participants with 2, 3, and ≥4 versus ≤1 ideal Life's Simple 7 factors were 0.99 (95% confidence interval [CI], 0.74-1.33), 0.77 (95% CI, 0.57-1.03), and 0.51 (95% CI, 0.33-0.79), respectively. Masked daytime hypertension was less common among participants with ideal versus poor levels of physical activity (ratio, 0.74; 95% CI, 0.56-1.00), ideal or intermediate levels pooled together versus poor diet (prevalence ratio, 0.73; 95% CI, 0.58-0.91), ideal versus poor levels of cigarette smoking (prevalence ratio, 0.61; 95% CI, 0.46-0.82), and ideal versus intermediate levels of clinic BP (prevalence ratio, 0.28, 95% CI, 0.16-0.48). Better cardiovascular health is associated with a lower preva lence of masked hypertension.

Masked Hypertension and Cardiovascular Disease Events in a Prospective Cohort of Blacks: The Jackson Heart Study.

Masked hypertension, defined as nonelevated clinic blood pressure (BP) with elevated out-of-clinic BP, has been associated with increased cardiovascular disease (CVD) risk in Europeans and Asians. Few data are available on masked hypertension and CVD and mortality risk among blacks. We analyzed data from the Jackson Heart Study, a prospective cohort study of blacks. Analyses included participants with clinic-measured systolic/diastolic BP <140/90 mm Hg who completed ambulatory BP monitoring after the baseline examination in 2000 to 2004 (n=738). Masked daytime (10:00 am-8:00 pm) hypertension was defined as mean ambulatory systolic/diastolic BP ≥135/85 mm Hg. Masked nighttime (midnight to 6:00 am) hypertension was defined as mean ambulatory systolic/diastolic BP ≥120/70 mm Hg. Masked 24-hour hypertension was defined as mean systolic/diastolic BP ≥130/80 mm Hg. CVD events (nonfatal/fatal stroke, nonfatal myocardial infarction, or fatal coronary heart disease) and deaths identified through December 2010 were adjudicated. Any masked hypertension (masked daytime, nighttime, or 24-hour hypertension) was present in 52.2% of participants; 28.2%, 48.2% and 31.7% had masked daytime, nighttime, and 24-hour hypertension, respectively. There were 51 CVD events and 44 deaths during a median follow-up of 8.2 and 8.5 years, respectively. CVD rates per 1000 person-years (95% confidence interval) in participants with and without any masked hypertension were 13.5 (9.9-18.4) and 3.9 (2.2-7.1), respectively. The multivariable adjusted hazard ratio (95% confidence interval) for CVD was 2.49 (1.26-4.93) for any masked hypertension and 2.86 (1.59-5.13), 2.35 (1.23-4.50), and 2.52 (1.39-4.58) for masked daytime, nighttime, and 24-hour hypertension, respectively. Masked hypertension was not associated with all-cause mortality. Masked hypertension is common and associated with increased risk for CVD events in blacks.

Masked Hypertension and Incident Clinic Hypertension Among Blacks in the Jackson Heart Study.

Masked hypertension, defined as nonelevated clinic blood pressure (BP) and elevated out-of-clinic BP may be an intermediary stage in the progression from normotension to hypertension. We examined the associations of out-of-clinic BP and masked hypertension using ambulatory BP monitoring with incident clinic hypertension in the Jackson Heart Study, a prospective cohort of blacks. Analyses included 317 participants with clinic BP <140/90 mm Hg, complete ambulatory BP monitoring, who were not taking antihypertensive medication at baseline in 2000 to 2004. Masked daytime hypertension was defined as mean daytime blood pressure ≥135/85 mm Hg, masked night-time hypertension as mean night-time BP ≥120/70 mm Hg, and masked 24-hour hypertension as mean 24-hour BP ≥130/80 mm Hg. Incident clinic hypertension, assessed at study visits in 2005 to 2008 and 2009 to 2012, was defined as the first visit with clinic systolic/diastolic BP ≥140/90 mm Hg or antihypertensive medication use. During a median follow-up of 8.1 years, there were 187 (59.0%) incident cases of clinic hypertension. Clinic hypertension developed in 79.2% and 42.2% of participants with and without any masked hypertension, 85.7% and 50.4% with and without masked daytime hypertension, 79.9% and 43.7% with and without masked night-time hypertension, and 85.7% and 48.2% with and without masked 24-hour hypertension, respectively. Multivariable-adjusted hazard ratios (95% confidence interval) of incident clinic hypertension for any masked hypertension and masked daytime, night-time, and 24-hour hypertension were 2.13 (1.51-3.02), 1.79 (1.24-2.60), 2.22 (1.58-3.12), and 1.91 (1.32-2.75), respectively. These findings suggest that ambulatory BP monitoring can identify blacks at increased risk for developing clinic hypertension.

Prevalence of Masked Hypertension and Its Association With Subclinical Cardiovascular Disease in African Americans: Results From the Jackson Heart Study.

BACKGROUND: Studies consisting mostly of whites have shown that the prevalence of masked hypertension differs by prehypertension status. Using data from the Jackson Heart Study, an exclusively African American population-based cohort, we evaluated the association of masked hypertension and prehypertension with left ventricular mass index and common carotid intima media thickness. METHODS AND RESULTS: At the baseline visit, clinic blood pressure (CBP) measurement and 24-hour ambulatory blood pressure monitoring were performed. Masked hypertension was defined as mean systolic/diastolic CBP <140/90 mm Hg and mean daytime systolic/diastolic ambulatory blood pressure ≥135/85 mm Hg. Clinic hypertension was defined as mean systolic/diastolic CBP ≥140/90 mm Hg. Normal CBP was defined as mean systolic/diastolic CBP <120/80 mm Hg and prehypertension as mean systolic/diastolic CBP 120 to 139/80 to 89 mm Hg. The analytic sample included 909 participants. Among participants with systolic/diastolic CBP <140/90 mm Hg, the prevalence of masked hypertension and prehypertension was 27.5% and 62.4%, respectively. The prevalence of masked hypertension among those with normal CBP and prehypertension was 12.9% and 36.3%, respectively. In a fully adjusted model, which included prehypertension status and antihypertensive medication use as covariates, left ventricular mass index was 7.94 g/m(2) lower among those without masked hypertension compared to participants with masked hypertension (P<0.001). Left ventricular mass index was also 4.77 g/m(2) lower among those with clinic hypertension, but this difference was not statistically significant (P=0.068). There were no significant differences in left ventricular mass index between participants with and without masked hypertension, or clinic hypertension. CONCLUSIONS: Masked hypertension was common among African Americans with prehypertension and also normal CBP, and was associated with subclinical cardiovascular disease.

Prevalence, Determinants, and Clinical Significance of Masked Hypertension in a Population-Based Sample of African Americans: The Jackson Heart Study.

BACKGROUND: The disproportionate rates of cardiovascular disease in African Americans may, in part, be due to suboptimal assessment of blood pressure (BP) with clinic BP measurements alone. To date, however, the prevalence of masked hypertension in African Americans has not been fully delineated. The purpose of this study was to evaluate masked hypertension prevalence in a large population-based sample of African Americans and examine its determinants and association with indices of target organ damage (TOD). METHODS: Clinic and 24-hour ambulatory BP monitoring were conducted in 972 African Americans enrolled in the Jackson Heart Study. Common carotid artery intima-media thickness, left ventricular mass index, and the urinary albumin:creatinine excretion ratio were evaluated as indices of TOD. RESULTS: Masked hypertension prevalence was 25.9% in the overall sample and 34.4% in participants with normal clinic BP. All indices of TOD were significantly higher in masked hypertensives compared to sustained normotensives and were similar between masked hypertensives and sustained hypertensives. Male gender, smoking, diabetes, and antihypertensive medication use were independent determinants of masked hypertension in multivariate analyses. CONCLUSIONS: In this population-based cohort of African Americans, approximately one-third of participants with presumably normal clinic BP had masked hypertension when BP was assessed in their daily environment. Masked hypertension was accompanied by a greater degree of TOD in this cohort.

Prevalence of masked hypertension in African Americans.

Masked hypertension (MH), the presence of normal office blood pressure (BP) with elevated ambulatory pressure, has been shown to correlate with organ damage. Population-based studies from Europe and Asia estimate a prevalence of 8.5% to 15.8%. Two small studies in African Americans estimate a prevalence >40%. Therefore, the authors utilized ambulatory BP monitoring (ABPM) to identify the prevalence of MH in our African American population. Pressure was recorded every 30 minutes while awake and every 60 minutes while asleep. Patients with 24-hour average BP ≥ 135/85 mm Hg, awake average BP ≥ 140/90 mm Hg, or asleep average BP ≥ 125/75 mm Hg had MH. Seventy-three participates had valid data. The mean age of the patients was 49.8 years, mean body mass index was 31.1, and 39 patients (53%) were women. Thirty-three patients (45.2%) had MH. Patients with MH had higher clinic systolic BP and trended toward higher BMI values. The authors corroborated the high prevalence of MH in African Americans. ABPM is critical to diagnose hypertension in African Americans, particularly in those with high-normal clinic pressure and obesity.

White-coat and masked hypertension are associated with carotid atherosclerosis in a general population: the Hisayama study.

BACKGROUND AND PURPOSE: On the basis of combined measurements of clinic blood pressure (CBP) and home blood pressure (HBP), blood pressure status can be divided into normotension, white-coat hypertension (WCHT), masked hypertension (MHT), and sustained hypertension (SHT). Despite the clear impact of MHT and SHT on clinical and subclinical arterial disease, uncertainty about the influence of WCHT remains. The objective of this study was to investigate the associations of WCHT, MHT, and SHT with carotid atherosclerosis in a general population. METHODS: This is a cross-sectional survey of 2915 community-dwelling Japanese aged ≥ 40 years. Normotension was defined as CBP<140/90 and HBP<135/85 mm Hg; WCHT, CBP ≥ 140/90 and HBP<135/85 mm Hg; MHT, CBP<140/90 and HBP ≥ 135/85 mm Hg; and SHT, CBP ≥ 140/90 and HBP ≥ 135/85 mm Hg. Mean intima-media thickness of carotid arteries was measured using a computer-automated system, and carotid stenosis was defined as diameter stenosis ≥ 30%. RESULTS: There were 1374 subjects (47.1%) with normotension, 200 (6.9%) with WCHT, 639 (21.9%) with MHT, and 702 (24.1%) with SHT. The geometric average of mean intima-media thickness was significantly higher among subjects with WCHT (0.73 mm), MHT (0.77 mm), and SHT (0.77 mm) than those with normotension (0.67 mm; all P<0.001 versus normotension). Compared with normotension, all types of hypertension were also associated with increased likelihood of carotid stenosis (age- and sex-adjusted odds ratio, 2.36 [95% confidence interval, 1.27-4.37] for WCHT, 1.95 [1.25-3.03] for MHT, and 3.02 [2.01-4.54] for SHT). These associations remained significant even after adjustment for other cardiovascular risk factors. CONCLUSIONS: WCHT, as well as MHT, and SHT were associated with carotid atherosclerosis in a general Japanese population.