Anthropometric and lifestyle factors associated with white-coat, masked and sustained hypertension in a Chinese population

Hypertension in China: epidemiology and treatment initiatives

The past two to three decades have seen a steady increase in the prevalence of hypertension in China, largely owing to increased life expectancy and lifestyle changes (particularly among individuals aged 35-44 years). Data from the China hypertension survey conducted in 2012-2015 revealed a high prevalence of grade 3 hypertension (systolic blood pressure ≥180 mmHg and diastolic blood pressure ≥110 mmHg) in the general population, which increased with age to up to 5% among individuals aged ≥65 years. The risk profile of patients with hypertension in China has also been a subject of intense study in the past 30 years. Dietary sodium and potassium intake have remained largely the same in China in the past three decades, and salt substitution strategies seem to be effective in reducing blood pressure levels and the risk of cardiovascular events and death. However, the number of individuals with risk factors for hypertension and cardiovascular disease in general, such as physical inactivity and obesity, has increased dramatically in the same period. Moreover, even in patients diagnosed with hypertension, their disease is often poorly managed owing to a lack of patient education and poor treatment compliance. In this Review, we summarize the latest epidemiological data on hypertension in China, discuss the risk factors for hypertension that are specific to this population, and describe several ongoing nationwide hypertension control initiatives that target these risk factors, especially in the low-resource rural setting.

Accuracy of screening strategies for masked hypertension: a large-scale nationwide study based on home blood pressure monitoring

This study compared the ability of guideline-proposed office blood pressure (OBP) screening thresholds [European Society of Hypertension (ESH) guidelines: 130/85 mmHg for individuals with an OBP < 140/90 mmHg; American College of Cardiology/American Heart Association (ACC/AHA) guidelines: 120/75 mmHg for individuals with an OBP < 130/80 mmHg] and novel screening scores to identify normotensive individuals at high risk of having masked hypertension (MH) in an office setting. We cross-sectionally evaluated untreated participants with an OBP < 140/90 mmHg (n = 22,266) and an OBP < 130/80 mmHg (n = 10,005) who underwent home blood pressure monitoring (HBPM) (derivation cohort) from 686 Brazilian sites. MH was defined according to criteria suggested by the ESH (OBP < 140/90 mmHg; HBPM ≥ 135/85 mmHg), Brazilian Society of Cardiology (BSC) (OBP < 140/90 mmHg; HBPM ≥ 130/80 mmHg) and ACC/AHA (OBP < 130/80 mmHg; HBPM ≥ 130/80 mmHg). Scores were generated from multivariable logistic regression coefficients between MH and clinical variables (OBP, age, sex, and BMI). Considering the ESH, BSC, and ACC/AHA criteria, 17.2%, 38.5%, and 21.2% of the participants had MH, respectively. Guideline-proposed OBP screening thresholds yielded area under curve (AUC) values of 0.640 (for ESH criteria), 0.641 (for BSC criteria), and 0.619 (for ACC/AHA criteria) for predicting MH, while scores presented as continuous variables or quartiles yielded AUC values of 0.700 and 0.688 (for ESH criteria), 0.720 and 0.709 (for BSC criteria), and 0.671 and 0.661 (for ACC/AHA criteria), respectively. Further analyses performed with alternative untreated participants (validation cohort; n = 2807 with an OBP < 140/90 mmHg; n = 1269 with an OBP < 130/80 mmHg) yielded similar AUC values. In conclusion, the accuracy of guideline-proposed OBP screening thresholds in identifying individuals at high risk of having MH in an office setting is limited and is inferior to that yielded by scores derived from simple clinical variables.

Association between Cardio-Ankle Vascular Index and Masked Uncontrolled Hypertension in Hypertensive Patients: A Cross-Sectional Study

Detection of masked uncontrolled hypertension (MUCH) that was defined for treated hypertensive individuals who had normal office blood pressure (BP) but elevated ambulatory BP remains largely challenging. Arterial stiffness is one of the leading risk markers for hypertension and can be clinically assessed by the cardio-ankle vascular index (CAVI). This study aimed to evaluate the association between CAVI and MUCH. A total of 155 hypertensive patients were included with their office BP levels and ambulatory BP monitoring measurements, which were divided into controlled hypertension (CH), MUCH, and sustained uncontrolled hypertension (SUCH) groups, respectively. There were 48 patients with CH, 56 patients with MUCH, and 51 patients with SUCH. Both MUCH and SUCH groups had a significantly higher CAVI than the CH group (9.05 (8.20-9.91) vs. 8.33 (7.75-9.15), p = 0.017, and 9.75 (8.35-10.50) vs. 8.33 (7.75-9.15), p = 0.002, respectively). There was no significant difference in CAVI values between the MUCH and SUCH groups. Multinomial logistic regression analysis exhibited that compared with the CH group, increased CAVI levels were positively associated with the presence of MUCH and SUCH (OR 2.046, 95% CI (1.239-3.381), p = 0.005; OR 2.215, 95% CI (1.310-3.747), p = 0.003) after adjusting for confounders. However, there was a similar trend of the CAVI in the MUCH and SUCH groups (OR 0.924, 95% CI (0.629-1.356), p = 0.686). In summary, our findings support, for the first time, the novel notion that CAVI as an arterial stiffness parameter is an independent risk factor for MUCH, being equally important to MUCH and SUCH. When the assessed CAVI is high in hypertensive patients with normotensive office BP levels, it is necessary to further investigate with a 24 h ambulatory BP monitoring to estimate the longstanding BP control. CAVI may be used as a noninvasive indicator to identify patients with MUCH earlier.

Ambulatory blood pressure monitoring for the management of hypertension

ABSTRACT

Ambulatory blood pressure monitoring (ABPM) has become indispensable in the current management of hypertension. ABPM is particularly useful in the accurate diagnosis of hypertension. Its diagnostic thresholds had been recently established based on hard clinical outcomes. Cross-classification of patients according to office and ambulatory blood pressure identifies white-coat, masked, and sustained hypertension. ABPM is also useful in cardiovascular (CV) risk assessment. It provides information on daytime and nighttime blood pressure and circadian rhythm, particularly nighttime blood pressure dipping. Nighttime blood pressure is predictive of CV risk independent of office and daytime blood pressure. Isolated nocturnal hypertension is a special form of masked hypertension, with normal daytime but elevated nocturnal blood pressure. It also helps in the evaluation of blood pressure fluctuation and variation, such as morning blood pressure surge and reading-to-reading blood pressure variability. ABPM may derive several other indexes, such as ambulatory blood pressure index and salt sensitivity index, which may be useful in CV evaluations.

Progression of Type B Intramural Hematoma Patients with Obstructive Sleep Apnea

OBJECTIVE

This study aimed to estimate the influence of obstructive sleep apnea (OSA) on type B intramural hematoma (IMHB) progression.

METHODS

All 127 patients received sleep evaluations and esophageal pressure measurements. Variables associated with aorta-related adverse events and mortality were summarized by logistic regression analysis and Cox proportional hazard models. Competing risk analysis of death was used to estimate aorta-related and non-aorta-related mortality.

RESULTS

The OSA group had a higher aorta-related adverse events rate (46% vs. 4%, P<0.001). The mean nighttime systolic pressure (OR, 1.24; 95% CI, 1.11-1.38, P<0.001) was associated with aorta-related adverse events during the acute phase. Thoracic endovascular aortic repair (TEVAR) (HR, 16.2; 95% CI, 7.68-34.22, P<0.001) and mean morning systolic pressure (HR, 1.43; 95% CI, 1.22-1.68, P<0.001) were associated with a higher rate of occurrence of aorta-related adverse events. The occurrence of OSA (HR, 3.19; 95% CI, 2.57-12.15, P<0.001) and mean morning systolic pressure (HR, 1.59; 95% CI, 1.27-2.01, P=0.002) were significantly associated with aorta-related mortality. Competing risk analysis revealed significantly higher aorta-related mortality in the OSA group (11.8% vs. 2.0%, P=0.0412). A neutrophil-to-lymphocyte ratio (NLR) of > 3.52 (specificity: 90.2%, sensitivity: 89.5%) and a mean platelet volume-to-platelet ratio (MPV/PLT) of > 0.049 (specificity: 98.0%, sensitivity: 98.7%) have diagnostic value for detecting OSA in IMHB.

CONCLUSIONS

OSA leads to a higher aorta-related adverse event rate and mortality in patients with IMHB. Variables associated with outcomes include TEVAR, mean morning/nighttime systolic pressure and OSA. The NLR and MPV/PLT ratios are valuable for detecting OSA in IMHB patients.

Diagnostic performance of clinic and home blood pressure measurements compared with ambulatory blood pressure: a systematic review and meta-analysis

BACKGROUND

Clinic blood pressure measurement (CBPM) is currently the most commonly used form of screening for hypertension, however it might have a problem detecting white coat hypertension (WCHT) and masked hypertension (MHT). Home blood pressure measurement (HBPM) may be an alternative, but its diagnostic performance is inconclusive relative to CBPM. Therefore, this systematic review aimed to estimate the performance of CBPM and HBPM compared with ambulatory blood pressure measurement(ABPM) and to pool prevalence of WCHT and MHT.

METHODS

Medline, Scopus, Cochrane Central Register of Controlled Trials and WHO's International Clinical Trials Registry Platform databases were searched up to 23rd January 2020. Studies having diagnostic tests as CBPM or HBPM with reference standard as ABPM, reporting sensitivity and specificity of both tests and/or proportion of WCHT or MHT were eligible. Diagnostic performance of CBPM and HBPM were pooled using bivariate mixed-effect regression model. Random effect model was applied to pool prevalence of WCHT and MHT.

RESULTS

Fifty-eight studies were eligible. Pooled sensitivity, specificity, and diagnostic odds ratio (DOR) of CBPM, when using 24-h ABPM as the reference standard, were 74% (95% CI: 65-82%), 79% (95% CI: 69%, 87%), and 11.11 (95% CI: 6.82, 14.20), respectively. Pooled prevalence of WCHT and MHT were 0.24 (95% CI 0.19, 0.29) and 0.29 (95% CI 0.20, 0.38). Pooled sensitivity, specificity, and DOR of HBPM were 71% (95% CI 61%, 80%), 82% (95% CI 77%, 87%), and 11.60 (95% CI 8.98, 15.13), respectively.

CONCLUSIONS

Diagnostic performances of HBPM were slightly higher than CBPM. However, the prevalence of MHT was high in negative CBPM and some persons with normal HBPM had elevated BP from 24-h ABPM. Therefore, ABPM is still necessary for confirming the diagnosis of HT.

A comparative meta-analysis of prospective observational studies on masked hypertension and masked uncontrolled hypertension defined by ambulatory and home blood pressure

BACKGROUND

In a comparative meta-analysis, we investigated the prognostic value of masked hypertension and masked uncontrolled hypertension defined by ambulatory or home blood pressure (BP) monitoring.

METHODS

We searched English literature published till 2 September 2018 to identify prospective observational studies. Masked hypertension was defined as a normal clinic BP (<140/90 mmHg) in the presence of an elevated 24 h, daytime or night-time ambulatory or home BP. Clinical outcomes included all-cause and cardiovascular mortality, and fatal and nonfatal cardiovascular, stroke, cardiac, coronary and renal disease events.

RESULTS

In total, 21 studies (n = 130 318) were included. Overall, compared with normotensive participants, masked hypertensive patients had a 5.7/2.9 mmHg higher clinic BP and 18.7/9.8 mmHg higher out-of-office BP. The pooled risk ratio for masked hypertension versus normotension was 1.67 (95% confidence interval, 1.32-2.13) and 2.19 (1.72-2.78) for all-cause (eight studies) and cardiovascular mortality (three studies), respectively, and 1.71 (1.53-1.91), 1.95 (1.36-2.80), 1.76 (1.33-2.33), 1.62 (0.27-9.60), 3.85 (2.03-7.31) for fatal and nonfatal cardiovascular (15 studies), stroke (two studies), cardiac (two studies), coronary (two studies) and renal disease events (two studies), respectively. Risk ratios for all-cause mortality (1.78 versus 1.40, P = 0.16) and fatal and nonfatal cardiovascular events (1.81 versus 1.61, P = 0.29) were similar between studies on ambulatory and home BP monitoring in the overall analyses. The analyses in subgroups according to treatment status (untreated, treated or mixed) and sampling approach (population or referred patients) were confirmatory.

CONCLUSION

Masked hypertension and masked uncontrolled hypertension were associated with unfavorable clinical outcomes, regardless of the out-of-office BP monitoring techniques.

Sex differences in masked hypertension: the Coronary Artery Risk Development in Young Adults study

OBJECTIVE

To evaluate the association of sex with masked hypertension, defined by out-of-clinic hypertension based on ambulatory blood pressure monitoring (ABPM) among adults without hypertension based on blood pressure (BP) measured in the clinic, after adjusting for potential confounders.

METHODS

We evaluated sex differences in the prevalence of masked hypertension and the difference between awake, or alternatively 24-h, ambulatory BP and clinic BP using multivariable adjusted models among 658 participants who underwent 24-h ABPM and had clinic SBP/DBP less than 140/90 mmHg during the Year 30 Exam of the Coronary Artery Risk Development in Young Adults study.

RESULTS

The mean age ± standard deviation (SD) of the participants was 54.8 ± 3.7 years, 58.4% were women, and 58.2% were black. The prevalence of any masked hypertension was 37.5% among women and 60.6% among men. In a model including adjustment for demographics, cardiovascular risk factors, antihypertensive medication, and clinic BP, the prevalence ratios (95% confidence intervals) comparing men versus women were 1.39 (1.18-1.63) for any masked hypertension, and 1.60 (1.28-1.99), 1.71 (1.36-2.15), and 1.40 (1.13-1.73) for masked awake, 24-h and asleep hypertension, respectively. In a fully adjusted model, the differences between mean awake ambulatory BP and clinic BP were 2.75 [standard error (SE) 0.92] mmHg higher for SBP and 3.61 (SE 0.58) mmHg higher for DBP among men compared with women.

CONCLUSION

The prevalence of masked hypertension on ABPM was high in both men and women. Male sex was an independent predictor of masked hypertension.

The antihypertensive effects of aerobic versus isometric handgrip resistance exercise

BACKGROUND

Aerobic exercise reduces blood pressure (BP) on average 5-7 mmHg among those with hypertension; limited evidence suggests similar or even greater BP benefits may result from isometric handgrip (IHG) resistance exercise.

METHOD

We conducted a randomized controlled trial investigating the antihypertensive effects of an acute bout of aerobic compared with IHG exercise in the same individuals. Middle-aged adults (n = 27) with prehypertension and obesity randomly completed three experiments: aerobic (60% peak oxygen uptake, 30 min); IHG (30% maximum voluntary contraction, 4 × 2 min bilateral); and nonexercise control. Study participants were assessed for carotid-femoral pulse wave velocity pre and post exercise, and left the laboratory wearing an ambulatory BP monitor.

RESULTS

SBP and DBP were lower after aerobic versus IHG (4.8 ± 1.8/3.1 ± 1.3 mmHg, P = 0.01/0.04) and control (5.6 ± 1.8/3.6 ± 1.3 mmHg, P = 0.02/0.04) over the awake hours, with no difference between IHG versus control (P = 0.80/0.83). Pulse wave velocity changes following acute exercise did not differ by modality (aerobic increased 0.01 ± 0.21 ms, IHG decreased 0.06 ± 0.15 ms, control increased 0.25 ± 0.17 ms, P > 0.05). A subset of participants then completed either 8 weeks of aerobic or IHG training. Awake SBP was lower after versus before aerobic training (7.6 ± 3.1 mmHg, P = 0.02), whereas sleep DBP was higher after IHG training (7.7 ± 2.3 mmHg, P = 0.02).

CONCLUSION

Our findings did not support IHG as antihypertensive therapy but that aerobic exercise should continue to be recommended as the primary exercise modality for its immediate and sustained BP benefits.

Persistence of Masked Hypertension in Chinese Patients

BACKGROUND

Masked hypertension (MH) has 10-15% prevalence and carries risk similar to that of sustained hypertension, but its short-term persistence remains uncertain.

METHODS

Forty-five patients with MH (mean age 52.2 years; 37.8% women) were enrolled in the placebo arm of a randomized clinical trial of Chinese medicine (NCT02156024) and followed up for 4 weeks. MH was office normotension (<140/90mm Hg) and daytime (8:00-18:00) hypertension (≥135/85mm Hg).

RESULTS

At enrolment, office and daytime systolic/diastolic blood pressure (BP) averaged 129.0/80.6mm Hg and 132.9/88.9mm Hg, respectively. Daytime BP thresholds for MH were met in 5 patients (11.1%) for systolic BP, in 25 (55.6%) for diastolic BP and in 15 (33.3%) for both. At follow-up, systolic and diastolic BP had not changed compared with baseline (P ≥ 0.12), except for a 2.1mm Hg decrease in office systolic BP (P = 0.049). MH remained present in 28 patients (62.2%; 95% CI, 48.1-76.3%), whereas 13 (28.9%; 15.7-42.1%) and 4 (8.9%; 0.6-17.2%) converted to normotension (daytime BP <135/85mm Hg) or sustained hypertension (office BP ≥140/90mm Hg), respectively. Substituting daytime by 24-hour BP, using 130/80mm Hg as threshold, produced consistent results. Systolic office BP at baseline independently predicted persistence of MH or progression to sustained hypertension at 4 weeks (odds ratio per 1 - SD increase, 3.49; 95% CI, 1.06-11.2; P = 0.04).

CONCLUSIONS

The information that MH persists over 4 weeks in over two-thirds of this sample of patients should inform future clinical trials and guidelines.

Epidemiology of masked and white-coat hypertension: the family-based SKIPOGH study

Objective

We investigated factors associated with masked and white-coat hypertension in a Swiss population-based sample.

Methods

The Swiss Kidney Project on Genes in Hypertension is a family-based cross-sectional study. Office and 24-hour ambulatory blood pressure were measured using validated devices. Masked hypertension was defined as office blood pressure<140/90 mmHg and daytime ambulatory blood pressure≥135/85 mmHg. White-coat hypertension was defined as office blood pressure≥140/90 mmHg and daytime ambulatory blood pressure<135/85 mmHg. Mixed-effect logistic regression was used to examine the relationship of masked and white-coat hypertension with associated factors, while taking familial correlations into account. High-normal office blood pressure was defined as systolic/diastolic blood pressure within the 130–139/85–89 mmHg range.

Results

Among the 652 participants included in this analysis, 51% were female. Mean age (±SD) was 48 (±18) years. The proportion of participants with masked and white coat hypertension was respectively 15.8% and 2.6%. Masked hypertension was associated with age (odds ratio (OR) = 1.02, p = 0.012), high-normal office blood pressure (OR = 6.68, p<0.001), and obesity (OR = 3.63, p = 0.001). White-coat hypertension was significantly associated with age (OR = 1.07, p<0.001) but not with education, family history of hypertension, or physical activity.

Conclusions

Our findings suggest that physicians should consider ambulatory blood pressure monitoring for older individuals with high-normal office blood pressure and/or who are obese.

How should we manage a patient with masked hypertension?

A number of studies have shown that masked hypertension (MH) confers an increased risk of target organ damage and of cardiovascular events suggesting that patients with MH would benefit from antihypertensive treatment. However, there is no general agreement about how this condition should be diagnosed. Although ambulatory blood pressure monitoring (ABPM) and self blood pressure measurement (SBPM) provide different and complementary clinical information, the recently published ESH/ESC guidelines for the management of arterial hypertension suggest that for initial assessment of the patient, SBPM may be more suitable in primary care and ABPM in specialist care. If SBPM provides borderline values it is advisable to confirm the diagnosis of MH with ABPM. As the prevalence of MH declines with repeated ABPMs the diagnosis of MH should be based on at least two ABPMs. Patients with MH should undergo a careful diagnostic work-up to assess the existence of additional risk factors including a worsened metabolic profile and the presence of target organ involvement. Treatment of the patient with MH should initially be addressed to improve the patient's lifestyle in order to decrease out-of-office blood pressure and to ameliorate metabolic data. If non-pharmacological measures are insufficient to normalize blood pressure, MH may benefit from pharmacological treatment but no clinical trial has been implemented as yet with the specific purpose of testing this hypothesis. Despite this lack of evidence, the 2013 ESH/ESC guidelines have recommended that in patients with MH also drug treatment should be considered because in patients with MH the risk of adverse outcome is very close to that in sustained hypertension. When ambulatory blood pressure is measured, pharmacological treatment may be modulated according to whether blood pressure is elevated during daytime hours or during sleep.

The impact of different anthropometric measures on sustained normotension, white coat hypertension, masked hypertension, and sustained hypertension in patients with type 2 diabetes

BACKGROUND

Many studies have aimed to determine whether body mass index (BMI), waist circumference (WC), or waist to hip ratio (WHR) best predicts hypertension in diabetic patients, with conflicting results. However, no study has examined the specific relationship between these anthropometric parameters with sustained normotension (SNT), white coat hypertension (WCHT), masked hypertension (MHT), and sustained hypertension (SHT) based on office and ambulatory blood pressure (BP) measurements in these patients.

METHODS

Patients with newly diagnosed type 2 diabetes underwent the following procedures: history taking, measurements of anthropometric parameters, office and ambulatory BP measurements, physical examination, laboratory analysis, and random and 24-hour urine analysis.

RESULTS

In total, there were 65 dippers and 37 nondipper patients. None of the anthropometric parameters were different between the dippers and the nondippers. There were 25 patients with SNT, 32 with WCHT, seven with MHT, and 38 with SHT. A comparison of anthropometric parameters between these four groups of patients showed that WC (P=0.016) and WHR (P=0.015) were different among all groups. According to regression analysis, only BMI was independently related with MHT (odds ratio [OR], 1.373, P=0.022), whereas only WC has been associated with SHT (OR, 1.321, P=0.041).

CONCLUSION

Among anthropometric parameters, only WC and WHR were different in SNT, WCHT, MHT, and SHT in newly diagnosed patients with type 2 diabetes.

Use of ambulatory blood pressure monitoring to guide hypertensive therapy

OPINION STATEMENT

With the advent of noninvasive 24-hour ambulatory blood pressure monitoring (ABPM), clinicians have access to a wealth of individualized data for the hypertensive patient. This has led to a greater understanding of the pathophysiology of hypertension and its complications. This tool has provided more precise diagnostic criteria for hypertension and helped discover those with white coat and masked hypertension. Patterns noted on ABPM and correlated with outcomes have allowed for more accurate identification of patients at high risk of cardiovascular (CV) events, and have offered an additional prognostic tool. In addition, ABPM allows for the assessment of the efficacy and adequacy of blood pressure treatment. In the current paper, we will describe the essential components of ABPM, review the evidence detailing the prognostic information that can be derived from its use, highlight clinical scenarios wherein ABPM can offer invaluable diagnostic information, and describe applications of ABPM that evaluate the efficacy of treatment of the hypertensive patient.

The relationship between exercise capacity and masked hypertension in sedentary patients with diabetes mellitus

AIM

Although exaggerated blood pressure responses (EBPR) to exercise have been related to future hypertension and masked hypertension (MHT), the relationship between exercise capacity and MHT remains unclear. A sedentary life style has been related to increased cardiovascular mortality, diabetes mellitus (DM), and hypertension. In this study, we aimed to examine the relationship between exercise capacity and MHT in sedentary patients with DM.

METHODS

This study included 85 sedentary and normotensive patients with DM. Each patient's daily physical activity level was assessed according to the INTERHEART study. All patients underwent an exercise treadmill test, and exercise duration and capacity were recorded. Blood pressure (BP) was recorded during all exercise stages and BP values ≥ 200/110 mmHg were accepted as EBPR. MHT was diagnosed in patients having an office BP <140/90 mmHg and a daytime ambulatory BP >135/85 mmHg. Patients were divided into two groups according to their ambulatory BP monitoring (MHT and normotensive group).

RESULTS

The prevalence of MHT was 28.2%. Exercise duration and capacity were lower in the MHT group than in the normotensive group (p<0.05) and were negatively correlated with age, HbA1c, mean daytime BP, and mean 24 hour BP. Peak exercise systolic BP and the frequency of EBPR were both increased in the MHT group (25.0% and 8.1%, respectively, p=0.03). According to a multivariate regression, exercise capacity (OR: 0.61, CI95%: 0.39-0.95, p=0.03), EBPR (OR: 9.45, CI95%: 1.72-16.90, p=0.01), and the duration of DM (OR: 0.84, CI95%: 0.71-0.96, p=0.03) were predictors of MHT.

CONCLUSION

Exercise capacity, EBPR, and the duration of DM were predictors of MHT in sedentary subjects with DM.

High sodium intake is associated with masked hypertension in Japanese patients with type 2 diabetes and treated hypertension

BACKGROUND

Knowledge regarding the association between dietary sodium intake and the incidence of masked hypertension is limited.

METHODS

A total of 193 Japanese type 2 diabetic outpatients who had been treated with antihypertensive agents and with office blood pressures <140/90 mm Hg were recruited. Masked hypertension was defined as having office blood pressure <140/90 mm Hg and 24-h mean ambulatory blood pressure ≥130/80 mm Hg. The dietary sodium intake was estimated by measuring the 24-h urinary sodium excretion.

RESULTS

Masked hypertension was found in 128 (66.3%) patients. An age- and sex-adjusted univariate logistic regression analysis showed that urinary albumin excretion, renin-angiotensin system inhibitor use, office systolic blood pressure, and amount of dietary sodium intake were significantly associated with masked hypertension. A multivariate logistic regression analysis also identified an older age, renin-angiotensin system inhibitor use, an office elevated systolic blood pressure, and high dietary sodium intake to be independently associated with masked hypertension. When compared with those who consumed a low salt diet (sodium <120 mEq/day), the odds ratio for the risk of exhibiting masked hypertension in patients who consumed a medium salt diet (sodium 120 to <200 mEq/day) or a high salt diet (sodium ≥200 mEq/day) were 5.3 (P < 0.001) and 12.6 (P < 0.001), respectively.

CONCLUSIONS

Masked hypertension is a common feature in type 2 diabetic patients being treated for hypertension. The observed association with sodium intake raised the hypothesis that excessive sodium intake may play a part in the genesis of masked hypertension in these patients.

Masked hypertension: evidence of the need to treat

The diagnosis of masked hypertension has been made easier with the widespread availability of home blood pressure monitoring devices with levels of accuracy comparable to ambulatory blood pressure monitoring. The negative impact of masked hypertension on cardiovascular morbidity and mortality is evidenced by numerous well-designed clinic-based and population-based studies. The relationship of masked hypertension and target organ damage is also well documented. These two factors, combined with the robust evidence of reduced cardiovascular morbidity and mortality achieved with blood pressure treatment, makes the argument for actively identifying patients with masked hypertension and prescribing treatment similar to that for patients with sustained hypertension. In this paper, we review the evidence for the cardiovascular prognosis of masked hypertension compared with sustained hypertension, we review its impact on target organ damage, we propose an algorithm for the treatment of patients with masked hypertension, and we point out the pitfalls in adopting such an approach.

Job strain and masked hypertension

OBJECTIVES

To determine whether psychosocial work characteristics are associated with the prevalence of masked hypertension in a population of white collar workers.

METHODS

White-collar workers were recruited from three public organizations. Blood pressure (BP) was measured at the workplace for manual measurements (mean of the first three readings taken by a trained assistant) followed by ambulatory measurements (mean of all subsequent readings taken during the working day). Masked hypertension (MH) was defined as manual BP <140/90 mm Hg, and ambulatory BP ≥135/85 mm Hg. Job strain was evaluated, using the quadrant method for exposure assessment, as well as alternative formulations.

RESULTS

BP measurements were obtained from 2,357 workers (80% participation, 61% women; mean age, 44 years). For men, being in the active group (high psychological demands and high decision latitude) was associated with MH (adjusted odds ratio, 2.07; 95% confidence interval, 1.30-3.31). No significant association with a higher prevalence of MH was observed in women.

CONCLUSION

MH is associated with job strain in men. Workers in "active" job situations may be more likely to have the condition.

Masked hypertension: different blood pressure measurement methodology and risk factors in a working population

OBJECTIVES

To estimate the prevalence of masked hypertension when the same ambulatory device is used for both manual and ambulatory blood pressure measurements and to measure associations with lifestyle risk factors in a working population.

METHODS

White-collar workers were recruited from three public organizations. Blood pressure was measured at the workplace using Spacelabs 90207 for manual measurements (mean of the first three readings taken by a trained assistant) followed by ambulatory measurements (mean of every other reading obtained during the working day). Masked hypertension was defined as manual blood pressure measurement of less than 140/90 mmHg and ambulatory blood pressure measurement of at least 135/85 mmHg. Smoking, alcohol intake, BMI and leisure physical activity were also assessed.

RESULTS

Blood pressure measurements were obtained from 2370 workers (80% participation, 61% women; mean age = 44 years). Masked hypertension was diagnosed in 15.02% of the participants. The prevalence was higher in men [adjusted odds ratio (OR) = 2.38, 95% confidence interval (CI) = 1.86-3.05]. The prevalence in men increased with age (adjusted OR = 2.08 for 40-49 years, 95% CI = 1.33-3.26 and adjusted OR = 1.91 for > or =50 years, 95% CI = 1.20-3.04) and BMI (adjusted OR = 1.78 for BMI > or = 27, 95% CI = 1.21-2.64). The prevalence in women increased with BMI (adjusted OR = 1.65 for BMI > or =27, 95% CI = 1.14-2.39) and alcohol intake (adjusted OR = 2.12 for at least six drinks per week, 95% CI = 1.34-3.35).

CONCLUSION

Masked hypertension is frequent and still present when blood pressure is measured out of the office, using the same device for manual and ambulatory measurements. Sex, age, BMI and alcohol intake are associated with masked hypertension.

Prevalence, causes, and consequences of masked hypertension: a meta-analysis

BACKGROUND

Masked hypertension (MH) is a relatively newly detected condition of which little is known. More information about MH may help to improve overall antihypertensive health care. We aimed to investigate the prevalence, potential causes, and associated consequences of MH.

METHODS

We searched published literature using MEDLINE, EMBASE, and the Cochrane database completed with references cited in reviews and original study articles. We restricted our research to articles written in the English, German, French, and Spanish language. Studies were included only when the prevalence of MH was reported, office blood pressure (BP) values were given, and methods of BP measurements were described in detail. All data were extracted independently by two readers with a standardized protocol and data-collection form.

RESULTS

The prevalence of MH averaged 16.8% (95% confidence interval 13.0-20.5%). The MH prevalence was 7% for children and 19% for adults. MH prevalences did not differ significantly when determined with self or ambulatory BP measurement (21.1% vs. 16.8%; P = 0.42). Subjects with MH had significantly higher left ventricular mass index (LVMI) values than normotensives (110 vs. 98 g/m2; P < 0.01) but similar values as sustained hypertensives (109 g/m2). In addition, patients with MH were more often smokers than normotensives (mean difference 18%; P < 0.03).

CONCLUSIONS

MH strikes about a quarter of the patients who were initially classified as normotensives (based on office BP measurements) and of treated hypertensives. Patients with MH seem to have a similar cardiovascular risk as sustained hypertensives but they may remain undetected. The presence of MH seems to be a matter of a coincidently low office BP value not related to certain subject characteristics although the chance of its presence may be increased by smoking and antihypertensive treatment.