Masked Hypertension in Healthy Children and Adolescents: Who Should Be Screened?

PURPOSE OF REVIEW: The goal is to review masked hypertension (MH) as a relatively new phenomenon when patients have normal office BP but elevated out-of-office BP. Firstly, it was described in children in 2004. It has received increased attention in the past decade. RECENT FINDINGS: The prevalence of MH in different pediatric populations differs widely between 0 and 60% based on the population studied, definition of MH, or method of out-of-office BP measurement. The highest prevalence of MH has been demonstrated in children with chronic kidney disease (CKD), obesity, diabetes, and after heart transplantation. In healthy children but with risk factors for hypertension such as prematurity, overweight/obesity, diabetes, chronic kidney disease, or positive family history of hypertension, the prevalence of MH is 9%. In healthy children without risk factors for hypertension, the prevalence of MH is very low ranging 0-3%. In healthy children, only patients with the following clinical conditions should be screened for MH: high-normal/elevated office BP, positive family history of hypertension, and those referred for suspected hypertension who have normal office BP in the secondary/tertiary center.

Masked Hypertension in Pediatric Heart Transplant Recipients.

BACKGROUND: Masked hypertension (HTN), especially, isolated nocturnal HTN (INH) has been shown to be a risk factor for cardiovascular disease (CVD) but is not studied well in pediatric heart transplant (PHT) patients. Ambulatory blood pressure monitoring (ABPM) is known to identify patients with HTN but is not used routinely in PHT. METHODS: A single-center, prospective, cross-sectional study of PHT recipients was performed to observe the incidence of masked HTN using 24-h ABPM. The relationship between ABPM parameters and clinical variables was assessed using Spearman correlation coefficient. p value < 0.05 was considered significant. RESULTS: ABPM was performed in 34 patients, mean age 14 ± 5 years, median 5.5 years post-PHT. All patients had normal cardiac function, left ventricular mass index and blood pressure measurements in the clinic. Four patients had known prior HTN and on medications, one of them was uncontrolled. Of the remaining 30 patients, 18 new patients were diagnosed with masked HTN, of which 14 had INH. Diurnal variation was abnormal in 82% (28/34) patients. 24-h diastolic blood pressure (DBP) index correlated with glomerular filtration rate (GFR) (r = - 0.44, p = 0.01). There was no correlation between other ABPM parameters with tacrolimus trough levels. CONCLUSIONS: ABPM identified masked HTN in 60% of patients, with majority being INH. Abnormal circadian BP patterns were present in 82% and an association was found between GFR and DBP parameters. HTN, especially INH, is under-recognized in PHT recipients and ABPM has a role in their long-term care.

Blood Pressure Measurement and Treatment Decisions.

White-coat and masked hypertension are important hypertension phenotypes. Out-of-office blood pressure measurement is essential for the accurate diagnosis and monitoring of these conditions. This review summarizes literature related to the detection and diagnosis, prevalence, epidemiology, prognosis, and treatment of white-coat and masked hypertension. Cardiovascular risk in white-coat hypertension appears to be dependent on the presence of coexisting risk factors, whereas patients with masked hypertension are at increased risk of target organ damage and cardiovascular events. There is an unmet need for robust data to support recommendations around the use of antihypertensive treatment for the management of white-coat and masked hypertension.

Do children with solitary or hypofunctioning kidney have the same prevalence for masked hypertension?

BACKGROUND: Having a low nephron number is a well-known risk factor for hypertension. There is an inverse relationship between the filtration surface area and systemic hypertension. A significant percentage of masked hypertension can be detected in children with nephron loss by ambulatory blood pressure monitoring (ABPM). METHODS: We prospectively investigated ABPM results of children having reduced kidney mass with normal office blood pressures (BPs) and kidney function. Forty-three children with congenital solitary kidney (group 1), 11 children with acquired solitary kidney (group 2), and 76 children with hypofunctioning kidney (group 3) were compared with age, gender, and BMI-matched healthy control group (group 4). The dietary salt intake of 76 patients was evaluated as salt equivalent (g/day). The primary endpoint was change from baseline in mean 24-h ABPM variables and the proportion of patients with masked hypertension when assessed by ABPM. RESULTS: The masked hypertension ratio of all patients was 12.3% when assessed with ABPM. Night hypertension was significantly higher in all patient groups than in the control group (p = 0.01). Diastolic BP loads of groups 1 and 3 were higher than in controls (p = 0.024). Systolic BP loads were higher only in group 1 than in the control group (p = 0.003). The dietary salt equivalent of patients in group 1 correlated positively with 24-h SBP and mean arterial pressure (MAP) values. Patients with excessive dietary salt intake in group 1 had a significantly higher diastolic BP load than those without excessive salt intake in group 1 (p = 0.002). CONCLUSIONS: Masked hypertension can be seen in children with a solitary kidney or when one of the kidneys is hypofunctioning. Systolic BP loads are higher in children with congenital solitary kidney, and salt intake correlates with systolic BP profiles especially in those. Our results suggest that being born with a congenital solitary kidney increases predisposition to hypertension and salt sensitivity.

Masked hypertension and its associations with glycemic variability metrics in children and adolescents with type 1 diabetes.

BACKGROUND: Masked hypertension defined as having normal office blood pressure (BP) but hypertension detected by continuous BP monitoring has been observed in children and adolescents with type 1 diabetes (T1D). However, no study has evaluated whether masked hypertension is associated with glycemic variability (GV) in these patients. We hypothesized that masked hypertension might be associated with high GV in patients with T1D. METHODS: This cross-sectional study performed continuous glucose monitoring (CGM) in parallel with ambulatory blood pressure monitoring (ABPM) in T1D patients aged 6-21 years. Patients who had known hypertension were excluded. CGM data from the same day as ABPM was calculated for GV including standard deviation (SD), coefficient of variation (CV) of glucose levels, and unstable glycemia which was defined as having a CV of glucose levels ≥ 36%. RESULTS: Thirty-three patients had complete ABPM and CGM data. Mean (SD) age was 13.8 (3.8) years and mean (SD) duration of T1D was 5.4 (3.6) years. All patients had normal office BP, but ABPM showed masked hypertension in 9 patients (27%). In comparison with normotensive patients, patients with masked hypertension had longer duration of T1D (7.4 vs. 4.6 years, p = 0.049), higher insulin requirement (1.2 vs. 0.9 units/kg/day, p = 0.049), and higher SD of glucose (70.3 vs. 47.9 mg/dl, p = 0.038). Masked hypertension group had a greater number of patients (71% vs. 19%, p = 0.02) with unstable glycemia. Multivariate analysis revealed that unstable glycemia was associated with masked hypertension. CONCLUSIONS: The presence of unstable glycemia in children and adolescents with T1D is associated with masked hypertension. Graphical abstract.

Blood pressure phenotypes based on ambulatory monitoring in a general middle-aged population.

BACKGROUND: Ambulatory blood pressure monitoring (ABPM) is increasingly recommended for clinical use, but more knowledge about the prevalence and variability in ABPM-derived phenotypes in the general population is needed. We describe these parameters in the community-based Swedish CArdioPulmonary bioImage Study (SCAPIS) cohort. METHODS: We examined 5881 men and women aged 50-64 with 24-hour ABPM recordings using validated monitors. ABPM phenotypes were defined according to European guidelines. White coat hypertension was defined as elevated office BP (≥140/90 mmHg) with normal mean ambulatory BP (<135/85 mmHg in day-time, <120/70 mmHg in night-time, <130/80 mmHg over 24-h); and masked hypertension as normal office BP (<140/90 mmHg) with elevated mean ambulatory BP (≥135/85 mmHg in day-time, ≥120/70 mmHg in night-time, ≥130/80 mmHg over 24-h). Blood pressure variability was assessed using the coefficient of variation (CV), standard deviation (SD), and average real variability. RESULTS: Based on the ABPM recordings, 36.9% of participants had 24-h hypertension, 40.7% had day-time hypertension, and 37.6% nocturnal hypertension. Among participants treated with anti-hypertensive drugs, one in three had elevated office blood pressures, and more than half had elevated 24-h, day-time or nocturnal blood pressures. Among participants without anti-hypertensive drugs, only one in six had elevated office blood pressures, but one in three had elevated 24-h, day-time or nocturnal blood pressures. Men had higher 24-h blood pressures, more masked hypertension, but less white-coat hypertension than women. The prevalence of white-coat hypertension increased with age, but not the prevalence of masked hypertension. A positive association between blood pressure level and variability was observed, and within-person and between-person SD and CV were of similar magnitude. The variance in ABPM on repeated measurements was substantial. CONCLUSIONS: In the middle-aged general population, masked hypertension is an underappreciated problem on the population level.

Is Masked Hypertension an underlying Cause of Unexplained Left Ventricle Hypertrophy?

OBJECTIVES: Unexplained left ventricular hypertrophy (ULVH) is defined as increased wall thickness in the absence of conditions that predispose to hypertrophy. The aim of this study was to evaluate the rate of masked hypertension in patient with unexplained left ventricle hypertrophy. METHOD: A total of 120 consecutive unexplained left ventricle hypertrophy patients without overt hypertension and diabetes and 121 healthy control subjects were included in the study. After a complete medical history and laboratory examination, patients' height, weight, waist circumference heart rate, and office blood pressure were recorded. All subjects underwent ambulatory blood pressure monitoring, and transthoracic echocardiography. RESULTS: Mean age were similar between patients with ULVH and controls. There was no significant difference in total cholesterol, HDL, LDL cholesterol and triglyceride levels, left ventricle ejection fraction, between the groups. Prevalence of Masked hypertension was significantly higher in patients with ULVH than controls (28.3% vs 6.6%, p < .001). Left ventricular mass index (141.9 ± 16.8 g/cm2 vs. 67.3 ± 10.3 g/cm2, p < .001) was significantly higher in masked hypertensive patients with ULVH compared to normotensive ULVH and control subjects. CONCLUSION: In this study, we found high prevalence of masked hypertension in ULVH patients. Patients with ULVH should be screened by ABPM to detect possible masked hypertension.

Prognostic Significance of Ambulatory BP Monitoring in CKD: A Report from the Chronic Renal Insufficiency Cohort (CRIC) Study.

BACKGROUND: Whether ambulatory BP monitoring is of value in evaluating risk for outcomes in patients with CKD is not clear. METHODS: We followed 1502 participants of the Chronic Renal Insufficiency Cohort (CRIC) Study for a mean of 6.72 years. We evaluated, as exposures, ambulatory BP monitoring profiles (masked uncontrolled hypertension, white-coat effect, sustained hypertension, and controlled BP), mean ambulatory BP monitoring and clinic BPs, and diurnal variation in BP-reverse dipper (higher at nighttime), nondipper, and dipper (lower at nighttime). Outcomes included cardiovascular disease (a composite of myocardial infarction, cerebrovascular accident, heart failure, and peripheral arterial disease), kidney disease (a composite of ESKD or halving of the eGFR), and mortality. RESULTS: Compared with having controlled BP, the presence of masked uncontrolled hypertension independently associated with higher risk of the cardiovascular outcome and the kidney outcome, but not with all-cause mortality. Higher mean 24-hour systolic BP associated with higher risk of cardiovascular outcome, kidney outcome, and mortality, independent of clinic BP. Participants with the reverse-dipper profile of diurnal BP variation were at higher risk of the kidney outcome. CONCLUSIONS: In this cohort of participants with CKD, BP metrics derived from ambulatory BP monitoring are associated with cardiovascular outcomes, kidney outcomes, and mortality, independent of clinic BP. Masked uncontrolled hypertension and mean 24-hour BP associated with high risk of cardiovascular disease and progression of kidney disease. Alterations of diurnal variation in BP are associated with high risk of progression of kidney disease, stroke, and peripheral arterial disease. These data support the wider use of ambulatory BP monitoring in the evaluation of hypertension in patients with CKD. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/JASN/2020_09_24_JASN2020030236.mp3.

[CLINIC BLOOD PRESSURE MONITORING AS A PREDICTOR OF MASKED HYPERTENSION].

INTRODUCTION: Masked hypertension is strongly linked to morbidity and mortality. The phenomenon poses a challenge to physicians due to the difficult diagnosis. Recent studies have shown that the incidence may occur in 8.8% -16.6% of the population and up to 30.4% among people with borderline blood pressure. OBJECTIVES: To examine the prevalence of masked hypertension in the Israeli population and the clinic blood pressure status as a predictor of masked hypertension. METHODS: Interviewees were randomly recruited from among passers-by at Assuta Hospital in Ashdod. Those who were found to have normal and normal-high blood pressure ranges were included in the study. Ambulatory blood pressure monitoring was performed, and anthropometric measures were assessed. A statistical analysis compared groups according to their blood pressure clinical and ambulatory blood pressure categories. RESULTS: A total of 35 participants were included in this research. Masked hypertension was found among 35.3% of patients with normal range blood pressure and 27.7% of those in the borderline range. Significant differences were found between the normotensive group and the masked hypertension group in BMI, waist circumference, and clinical category of clinic diastolic blood pressure. CONCLUSIONS: A third of those with in-clinic normal blood pressure suffer from masked hypertension. Borderline in-clinic diastolic blood pressure is significantly associated with masked hypertension. DISCUSSION: This study presents higher masked hypertension rates than previously reported, the difference may be explained by differences in the nature and the lifestyle of the study population. The high incidence of the phenomenon indicates the need for further investigation of patients with in-clinic normal and borderline blood pressure.

Increased masked hypertension prevalence in patients with polycystic ovary syndrome (PCOS).

OBJECTIVE: Polycystic ovary syndrome (PCOS) is a common disorder with important clinical consequences. Many studies have proven that hypertension is one of the most important comorbid disorders in PCOS. Masked hypertension is defined as a presence of normal office blood pressure together with abnormal results in 24-h ambulatory blood pressure monitoring (ABPM). The prevalence of this condition in patients with PCOS is not well defined. The aim of this study was to evaluate the prevalence of masked hypertension in PCOS compared to control subjects. METHODS: Sixty patients with PCOS and 60 control subjects were enrolled in the study. All patients with PCOS and controls without a history of hypertension underwent physical examination including office blood pressure measurement, ABPM, and measurement of laboratory and anthropometric parameters. RESULTS: Mean age was 30.5 ± 6.6 in control group and 26.4 ± 7.1 year in patients with PCOS (p = .001). Twenty-four patients (40%) had masked hypertension in PCOS group whereas 11 patients (18.3%) in the control group (p = .009). Twenty-four-hour diastolic blood pressure (p = .03), daytime systolic (p < .001), and daytime diastolic blood pressure (p = .01) and nighttime systolic blood pressure (p = .01) were significantly higher in patients with PCOS compared with control group. CONCLUSIONS: This study demonstrates increased masked hypertension prevalence in patients with PCOS. We suggest that all patients with PCOS should undergo ambulatory blood pressure monitoring for detecting masked hypertension.

Masked Hypertension: A Systematic Review.

BACKGROUND: Masked phenomenon, Masked Hypertension (MHT) and Masked Uncontrolled Hypertension (MUCH) is a well-defined clinical entity. However, many aspects of MHT/MUCH remain unclear. METHODS: We systematically reviewed the published literature on MHT/MUCH from 1 January 2000 to 31 June 2018 with a particular focus on epidemiology, clinical significance, evaluation and management. Meta-analyses were performed with respect to prevalence, clinical significance and diagnostic agreement between home blood pressure (HBP) and ambulatory BP (ABP) measurements. RESULTS: The overall weighted-mean prevalence of masked phenomenon was 11% [9,14]; MHT 10% [9,11]; and MUCH 13% [8,17]. The weighted-mean prevalence when expressed as a proportion of patients with normal office BP was 32% [25,40]; MHT 28% [15,41]; and MUCH 43% [29,57]. The prevalence of masked phenomenon determined by ABP (11% [8,14]) and HBP (13% [9,16]), was similar. However, ABP appeared to have a greater sensitivity, i.e. proportion of patients diagnosed as having MHT/MUCH was greater with ABP than with HBP (22% v 16%, p<0.05), when both methodologies were applied to the same cohort of patients. The prevalence of MHT was influenced by ethnicities and comorbidities, and in case of MUCH by anti-hypertensive treatment. MHT/MUCH was associated with increased risk of fatal and non-fatal cardiac/cerebrovascular events (relative risk [RR] 2.09 [1.80, 2.44]), and the risk was comparable to sustained hypertension (SHT) (RR 2.26 [1.84, 2.78]). The increased risk occurred regardless of the method of out of office BP assessment; the relative risks for ABP and HBP were 2.38 [1.90, 2.98] and 1.90 [1.57, 2.29] respectively. The diagnostic agreement between ABP and HBP was only modest, kappa = 0.46 [0.40, 0.52], even though the percentage agreement was 83%. The evidence for the management of MHT was scant. CONCLUSIONS: MHT/MUCH is a common BP phenotype with a risk profile similar to that of SHT. Therefore, high risk patients should undergo out of office BP assessment, probably both by HBP and ABP, to confirm diagnosis and be considered for treatment.

The validity of a daytime ambulatory blood pressure to diagnose masked hypertension.

Masked hypertension (MH) is traditionally diagnosed with 24-hour ambulatory blood pressure monitoring (24-ABPM). This is relatively costly and could cause discomfort during the night. We studied the validity of daytime ABP (DT-ABPM) in young National Guard soldiers and determined the prevalence in comparison to the standard 24-ABPM. A prospective study of 196 soldiers aged 21-50 years, without a history of hypertension or antihypertensive medication use. Each participant was fitted with a 12h-ABPM. Patients were diagnosed with MH if the office blood pressure (OBP) was <140/90 mmHg and the average DT-ABPM was ≥135/85 mmHg. By pairing the average OBP with the 12 h-ABPM, the prevalence of MH was estimated as 18/196 (9.2%), the SBP MH (systolic blood pressure) of 8.2% and the DPB MH (diastolic blood pressure) of 3.1%.  When we compared the daytime prevalence with the 24 h-ABPM, and the average OBP, the prevalence of MH was 29/196 (14.8%). No statistically significant difference was noted (kappa=0.74; 95% CI: 0.59 to 0.88). We conclude that DT-ABPM is a good method and convenient to detect MH, with no statistically significant difference when compared to the 24 h-ABPM. The prevalence of MH in young healthy soldiers was unexpectedly high.

Removing the mask on hypertension (REMAH) study: Design; quality of blood pressure phenotypes and characteristics of the first 490 participants.

Purpose: Previous studies that evaluated the prevalence of hypertension in Nigeria were either clinic based, non-standardized or did not include out-of-clinic blood pressure (BP) measurement. Materials and Methods: We selected a rural and an urban community in one state in each of the 6 geopolitical zones of Nigeria. Five consecutive BP of adults older than 18 years were measured in the clinic following which, each participant was provided with a home BP device to obtain duplicate morning and evening BP for 3 days. Result: Out of 556 invited from Anambra State, South-East Nigeria, 490 (88%) consented. Overall, more women participated in both rural (115 vs 61, p < .0001) and urban (213 vs 101; p < .0001) sites. About 35.9% of participants had their home BP monitored. Of the 4890 clinic BP readings, 29.8%, 16.3%, 16.6%, 16.4% and 20.8% ended in 0,2,4,6 and 8 digits respectively. Only 0.8% ended in odd numbers. Of the identical BP readings,5 (0.20%), 6 (0.25%), 56 (2.30%) and 316 (12.9%) SBP and 8 (0.33%), 17 (0.70%), 93 (3.80%), 319 (13.1%) DBP had no difference in five, four, three and two values of the five consecutive readings. Conclusion: REMAH is feasible and the quality of BP will ensure that the final results are robust.

Masked Hypertension in CKD: Increased Prevalence and Risk for Cardiovascular and Renal Events.

PURPOSE OF REVIEW: Hypertension and chronic kidney disease (CKD) are inextricably linked. The causal nature of the relationship is bidirectional. This relationship holds when blood pressure is assessed in the clinic and outside the clinic with home and ambulatory blood pressure monitoring. Patients with CKD are more likely to have high-risk hypertension phenotypes, such as masked and sustained hypertension, and are at increased risk for cardiovascular disease. The purpose of this review is to describe the increased prevalence of masked hypertension in patients with CKD and then describe the increased risk for target organ damage and adverse clinical events associated with masked hypertension in patients with CKD. RECENT FINDINGS: The prevalence of masked hypertension is greater in patients with CKD than that of the general population. Recent studies have demonstrated that masked hypertension is associated with increased risk for target organ damage including left ventricular hypertrophy, elevated pulse wave velocity, proteinuria, and decreased estimated glomerular filtration rate in patients with CKD. Additionally, in patients with CKD, masked hypertension is associated with increased risk for cardiovascular disease, end-stage renal disease, and all-cause mortality. Patients with CKD are at increased risk for masked hypertension. Masked hypertension is associated with increased risk for target organ damage and adverse cardiovascular and renal outcomes in patients with CKD. Further research is necessary to better understand the pathophysiology of masked hypertension, the optimal method for diagnosing masked hypertension, and to determine whether masked hypertension is a modifiable risk factor.

Increased masked hypertension prevalence in patients with obesity.

OBJECTIVES: Masked hypertension is associated with an increased risk for cardiovascular conditions. The aim of the study was to evaluate the relationship obesity parameters, including body weight, waist circumference, and body mass index. METHODS: The study group consisted of 251 consecutive outpatient subjects without overt hypertension. Subjects were classified according to BMI. After a complete medical history and laboratory examination, patients' height, weight, waist circumference heart rate, and office blood pressure were recorded. All subjects underwent ambulatory blood pressure monitoring. Masked hypertension is defined as normal office blood pressure measurement and high ambulatory blood pressure level. RESULTS: Baseline characteristics in patients and controls were similar. Prevalence of Masked hypertension was significantly higher in patients with obesity than controls (30.9% vs 5.7%, p < 0.001). Body mass index (33.2 ± 4.3 vs 25.1 ± 2.7 p < 0.001), waist circumference (98.5 ± 11.7 vs 86.8 ± 8.8, p < 0.001), and weight (86.5 ± 11.8 vs. 69 ± 9.1, p < 0.001) in patients with obesity were significantly higher than in patients with normal weight. Office Systolic BP (121.8 ± 4.4 vs 120.5 ± 4.78, p = 0.035), ambulatory daytime systolic BP (128.8 ± 8.9 vs 124.5 ± 7.4, p < 0.001), ambulatory daytime diastolic BP (73.9 ± 9.5 vs 71.5 ± 7.0, p = 0.019), ambulatory night-time systolic BP in patients with obesity was significantly higher than in patients with normal weight. CONCLUSION: This study demonstrated that masked hypertension prevalence is higher in patients with obesity than control patients. It can be suggested that predefining obesity might be helpful in early detection of masked hypertension.

Masked Isolated Nocturnal Hypertension in Children and Young Adults.

Isolated nocturnal hypertension (INH) is characterized by normal daytime blood pressure (BP) and elevated nighttime BP diagnosed by ambulatory BP monitoring. Masked isolated nocturnal hypertension (MINH) is a subtype of INH in which office BP is normal. We studied the frequency and characteristics of INH and MINH in children and young adults. One hundred and ninety-eight subjects seen by the pediatric nephrology service were studied retrospectively. Isolated nocturnal hypertension (INH) and MINH were diagnosed according to daytime and nighttime ABP and office BP in the case of the latter. One hundred and eighteen subjects (60%) had normotension, 6 (3%) had isolated daytime hypertension, 32 (16%) had INH, and 42 (21%) had day-night hypertension. Sixteen subjects had MINH (8.1%). The underlying diseases of MINH were as follows: no underlying disease 9 (56%), renal disease 6 (38%), and endocrine disease 1 (6%). There was no significant difference in the underlying disease, gender, age, and BMI between MINH and INH with elevated office BP. In conclusion, MINH is present in children and young adults. Since there were no specific features for MINH, screening with ambulatory or home BP monitoring during sleep may be appropriate.

Left ventricular mass of persistent masked hypertension in Hong Kong Chinese adolescents: a 4-year follow-up study.

OBJECTIVE: In our previous study, the prevalence of childhood masked hypertension was 11%. This study aims to assess the left ventricular mass index of persistent masked hypertension and determine the factors of elevated left ventricular mass index in Hong Kong Chinese adolescents from a community cohort. DESIGN: Community prospective cohort study, follow-up of a case-control study in community. SUBJECTS: Patients with masked hypertension at baseline were invited to recheck ambulatory blood pressure for the persistence of masked hypertension. RESULTS: A total of 144 out of 165 patients with masked hypertension in the 2011/2012 ambulatory blood pressure survey consented to participate in the study. In all, 48 patients were found to have persistent masked hypertension by ambulatory blood pressure rechecking and were matched with normotensive controls by sex, age, and body height. The left ventricular mass (117.3±39.9 g versus 87.0±28.2 g versus 102.0±28.2 g) and left ventricular mass index (30.1±8.4 g/m2.7 versus 23.9±6.3 g/m2.7 versus 25.1±5.7 g/m2.7) were significantly higher in the persistent masked hypertension group (p<0.0001) compared with the patients without persistent masked hypertension and controls. In multivariate linear regression analysis, left ventricular mass index was found to be higher in male gender (ß=4.874, p<0.0001) and the patients with persistent masked hypertension (ß=2.796, p=0.003). In addition, left ventricular mass index was positively associated with body mass index z-score (ß=3.045, p<0.0001) and low-density lipoprotein cholesterol concentration (ß=1.634, p=0.015). CONCLUSIONS: Persistent masked hypertension in adolescents is associated with elevated left ventricular mass index.

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.

Comparisons of Office and 24-Hour Ambulatory Blood Pressure Monitoring in Children with Obstructive Sleep Apnea.

OBJECTIVE: To compare office blood pressure (BP) and 24-hour ambulatory BP (ABP) monitoring to facilitate the diagnosis and management of hypertension in children with obstructive sleep apnea (OSA). STUDY DESIGN: Children aged 4-16 years with OSA-related symptoms were recruited from a tertiary referral medical center. All children underwent overnight polysomnography, office BP, and 24-hour ABP studies. Multiple linear regression analyses were applied to elucidate the association between the apnea-hypopnea index and BP. Correlation and consistency between office BP and 24-hour ABP were measured by Pearson correlation, intraclass correlation, and Bland-Altman analyses. RESULTS: In the 163 children enrolled (mean age, 8.2 ± 3.3 years; 67% male). The prevalence of systolic hypertension at night was significantly higher in children with moderate-to-severe OSA than in those with primary snoring (44.9% vs 16.1%, P = .006). Pearson correlation and intraclass correlation analyses revealed associations between office BP and 24-hour BP, and Bland-Altman analysis indicated an agreement between office and 24-hour BP measurements. However, multiple linear regression analyses demonstrated that 24-hour BP (nighttime systolic BP and mean arterial pressure), unlike office BP, was independently associated with the apnea-hypopnea index, after adjustment for adiposity variables. CONCLUSIONS: Twenty-four-hour ABP is more strongly correlated with OSA in children, compared with office BP.

An Update on Masked Hypertension.

Masked hypertension refers to the phenomenon of having a non-elevated clinic blood pressure (BP) despite having an elevated out-of-clinic BP. Masked hypertension is a common phenotype with a cardiovascular risk profile similar to that of sustained hypertension, defined as elevated clinic and out-of-clinic BP. Current guidelines offer little guidance on the best practices for detecting and treating masked hypertension. This is in part due to insufficient evidence upon which to base recommendations as many questions remain regarding the optimal clinical management of masked hypertension. In this review, we will discuss the recent literature on masked hypertension related to disease prevalence, diagnosis, screening strategies, adverse outcomes, and treatment, and will highlight critical areas for future research.