Ambulatory blood pressure monitoring and risk of cardiovascular disease: a population based study

BACKGROUND: Information on the relationship between ambulatory blood pressure (BP) and cardiovascular disease in the general population is sparse. METHODS: Prospective study of a random sample of 1700 Danish men and women, aged 41 to 72 years, without major cardiovascular diseases. At baseline, ambulatory BP, office BP, and other risk factors were recorded. The end point was a combined end point consisting of cardiovascular mortality, ischemic heart disease, and stroke. RESULTS: After a mean follow-up of 9.5 years, 156 end points were recorded. In multivariate models, the relative risk (95% confidence interval) associated with increments of 10/5 mmHg of systolic/diastolic ambulatory BP were 1.35 (1.21-1.50) and 1.27 (1.16-1.39). The corresponding figures for office BP were 1.18 (1.09-1.29) and 1.11 (1.03-1.19). Compared with normotension (office BP <140/90 mm Hg; daytime BP <135/85 mm Hg) the relative risks associated with isolated office hypertension (office BP >/=140/90 mm Hg; daytime BP <135/85 mm Hg), isolated ambulatory hypertension (office BP <140/90 mm Hg; daytime BP >/=135/85 mm Hg), and sustained hypertension (office BP >/=140/90 mm Hg; daytime BP >/=135/85 mm Hg) were 0.66 (0.30-1.44), 1.52 (0.91-2.54), and 2.10 (1.45-3.06), respectively. A blunted BP decrease at night was a risk factor (P = .02) in subjects with daytime ambulatory hypertension, but not in subjects with daytime ambulatory normotension (P = .13). CONCLUSIONS: Ambulatory BP provided prognostic information about cardiovascular disease better than office BP. Isolated office hypertension was not a risk factor and isolated ambulatory hypertension tended to be associated with increased risk. A blunted BP decrease at night was a risk factor in subjects with daytime ambulatory hypertension.     

Detection of carotid atherosclerosis in individuals with masked hypertension and white-coat hypertension by self-measured blood pressure at home: the Ohasama study

OBJECTIVE: To investigate carotid atherosclerosis in individuals with masked hypertension (MHT) and white-coat hypertension (WCHT) in a general population. METHODS: Self-measurement of blood pressure at home (HBP) and casual blood pressure (CBP) measurements were recorded in 812 individuals aged at least 55 years (mean 66.4 years) from the general Japanese population. The intima-media thickness (IMT) of the near and far wall of both common carotid arteries was measured and averaged. The relationships between carotid atherosclerosis (IMT and plaque) and the four blood pressure groups (sustained normal blood pressure: HBP < 135/85 mmHg, CBP < 140/90 mmHg; WCHT: HBP < 135/85 mmHg, CBP >or= 140/90 mmHg; MHT: HBP >or= 135/85 mmHg, CBP < 140/90 mmHg; sustained hypertension: HBP >or= 135/85 mmHg, CBP >or= 140/90 mmHg) were examined using multivariate analysis adjusted for possible confounding factors. RESULTS: Adjusted IMT in individuals with sustained hypertension [0.77 mm; 95% confidence interval (CI) 0.75 to 0.79 mm] and MHT (0.77 mm; 95% CI 0.73 to 0.80 mm) was significantly greater than in those with sustained normal blood pressure (0.71 mm; 95% CI 0.69 to 0.72 mm) and WCHT (0.72 mm; 95% CI 0.71 to 0.74 mm) (P < 0.0001). The odds ratios for the presence of plaques in all four groups were similar to the trends in IMT. CONCLUSIONS: Our findings imply that CBP measurements alone are insufficient to distinguish individuals at high risk of carotid atherosclerosis from those at low risk. However, these individuals do have distinct HBP measurements, suggesting that HBP measurement could become a valuable tool for predicting carotid atherosclerosis.     

Prediction of stroke by home "morning" versus "evening" blood pressure values: the Ohasama study

Predictive power of self-measured blood pressure at home (home BP) for cardiovascular disease risk has been reported to be higher than casual-screening BP. However, the differential prognostic significance of home BP in the morning (morning BP) and in the evening (evening BP), respectively, has not been elucidated. In the Ohasama study, 1766 subjects (>or=40 years) were followed up for an average of 11 years. The predictive power for stroke incidence of evening BP was compared with that of morning BP as continuous variables. The Cox regression model demonstrated that evening BP and morning BP predicted future stroke risk equally. Subjects were also assigned to 1 of 4 categories based on home BP. In this analysis, stroke risk in morning hypertension ([HT] morning BP >or=135/85 mm Hg and evening BP <135/85 mm Hg; relative hazard (RH): 2.66; 95% CI:1.64 to 4.33) and that in sustained HT(morning BP and evening BP >or=135/85 mm Hg; RH: 2.38; 95% CI: 1.65 to 3.45) was significantly higher than that in normotension (morning BP and evening BP <135/85 mm Hg). The risk in morning HT was more remarkable in subjects taking antihypertensive medication (RH: 3.55; 95% CI: 1.70 to 7.38). Although the risk in evening HT (morning BP <135/85 mm Hg and evening BP >or=135/85 mm Hg) was higher than that in normotension, the differences were not significant. In conclusion, morning BP and evening BP provide equally useful information for stroke risk, whereas morning HT, which indicates HT specifically observed in the morning, might be a good predictor of stroke, particularly among individuals using anti-HT medication.     

Subclinical arterial damage in untreated masked hypertensive subjects detected by home blood pressure measurement

BACKGROUND: Masked hypertension (MHT: normal office blood pressure [BP] + elevated BP out of the office) is a significant predictor of target organ damage and cardiovascular disease. The purpose of this study was to investigate the subclinical arterial damage in unmedicated subjects with MHT detected by home BP measurement. METHODS: We recruited 282 subjects not taking antihypertensive medication, who had at least one of the following five cardiovascular risk factors: high BP, hyperlipidemia, diabetes mellitus, current smoking, and chronic kidney disease. Furthermore, we classified them into four groups (normotension [NT], white-coat hypertension [WCHT], MHT, and sustained hypertension [SHT]) by office BP (140/90 mm Hg) and home BP (135/85 mm Hg) measurements. Arterial damage was evaluated by measuring carotid intima-media thickness (IMT) and brachial-ankle pulse wave velocity (baPWV). RESULTS: Subjects with MHT had a higher prevalence of habitual alcohol drinkers than the other groups, and higher pulse rates at home than those with NT and WCHT. After adjustment for covariates, carotid IMT was the highest in MHT among the four groups (mean: 1.01 v 0.83 mm for NT, 0.86 mm for WCHT, and 0.91 mm for SHT, all P < .01). The baPWV was also significantly higher in MHT than NT and WCHT (mean: 1940 v 1663 and 1733 cm/sec, all P < .01), whereas the difference between MHT and SHT (2023 cm/sec) was not significant. CONCLUSIONS: This study shows that masked hypertensives detected by home BP are at higher risk for increased arterial damage than normotensives or white-coat hypertensives, and potentially than sustained hypertensives.     

Left ventricular changes in isolated office hypertension: a blood pressure-matched comparison with normotension and sustained hypertension.

BACKGROUND: Isolated office (IO) hypertension is a benign condition according to some researchers, whereas others believe it is associated with cardiovascular abnormalities and increased cardiovascular risk. The aim of this study is to compare morphofunctional characteristics of the left ventricle (LV) in IO hypertensive subjects, normotensive subjects (hereafter, hypertensives and normotensives), and never-treated sustained hypertensives. The 3 groups were matched not only by age, sex, and body mass index but also by clinic blood pressure (BP) (IO hypertensives and sustained hypertensives) and daytime BP (IO hypertensives and normotensives). METHODS: We enrolled 42 IO hypertensives (clinic BP > 140 and/or 90 mm Hg and daytime BP < or = 130/80 mm Hg), 42 sustained hypertensives (clinic BP > 140 and/or 90 mm Hg and daytime BP > or = 140 and/or 90 mm Hg) and 42 normotensives (clinic BP < 135 and/or 85 mm Hg and daytime BP < or = 130/80 mm Hg). Left ventricular morphologic features and function were assessed using digitized M-mode echocardiography. RESULTS: Compared with normotensives, IO hypertensives had significantly thicker LV walls, increased LV mass, reduced diastolic function, increased prevalence of LV hypertrophy, and preclinical diastolic dysfunction. Sustained hypertensives, compared with IO hypertensives, had significantly thicker LV wall, higher LV mass, and lower diastolic function, whereas the prevalence of LV hypertrophy and preclinical diastolic dysfunction was greater than in IO hypertensives, but the difference did not reach statistical significance (P = .29). CONCLUSIONS: Comparing matched BP groups, IO hypertensives have LV morphofunctional characteristics considerably different from normotensives and qualitatively similar to sustained hypertensives. Therefore, our results support the hypothesis that IO hypertension should not be considered as simply a benign condition.     

Significance of white-coat hypertension in older persons with isolated systolic hypertension: a meta-analysis using the International Database on Ambulatory Blood Pressure Monitoring in Relation to Cardiovascular Outcomes population

The significance of white-coat hypertension in older persons with isolated systolic hypertension remains poorly understood. We analyzed subjects from the population-based 11-country International Database on Ambulatory Blood Pressure Monitoring in Relation to Cardiovascular Outcomes database who had daytime ambulatory blood pressure (BP; ABP) and conventional BP (CBP) measurements. After excluding persons with diastolic hypertension by CBP (≥90 mm Hg) or by daytime ABP (≥85 mm Hg), a history of cardiovascular disease, and persons <18 years of age, the present analysis totaled 7295 persons, of whom 1593 had isolated systolic hypertension. During a median follow-up of 10.6 years, there was a total of 655 fatal and nonfatal cardiovascular events. The analyses were stratified by treatment status. In untreated subjects, those with white-coat hypertension (CBP ≥140/<90 mm Hg and ABP <135/<85 mm Hg) and subjects with normal BP (CBP <140/<90 mm Hg and ABP <135/<85 mm Hg) were at similar risk (adjusted hazard rate: 1.17 [95% CI: 0.87-1.57]; P=0.29). Furthermore, in treated subjects with isolated systolic hypertension, the cardiovascular risk was similar in elevated conventional and normal daytime systolic BP as compared with those with normal conventional and normal daytime BPs (adjusted hazard rate: 1.10 [95% CI: 0.79-1.53]; P=0.57). However, both treated isolated systolic hypertension subjects with white-coat hypertension (adjusted hazard rate: 2.00; [95% CI: 1.43-2.79]; P<0.0001) and treated subjects with normal BP (adjusted hazard rate: 1.98 [95% CI: 1.49-2.62]; P<0.0001) were at higher risk as compared with untreated normotensive subjects. In conclusion, subjects with sustained hypertension who have their ABP normalized on antihypertensive therapy but with residual white-coat effect by CBP measurement have an entity that we have termed, "treated normalized hypertension." Therefore, one should be cautious in applying the term "white-coat hypertension" to persons receiving antihypertensive treatment.     

Masked hypertension in diabetes mellitus: a potential risk

The prevalence and clinical significance of masked hypertension (MHT) in diabetics have infrequently been described. The authors assessed the association of MHT (defined using a clinic blood pressure [BP] <140/90 mm Hg and daytime ambulatory BP > or = 135/85 mm Hg) with microvascular and macrovascular end organ damage in 81 clinically normotensive Japanese diabetic persons. The prevalence of silent cerebral infarcts (SCIs), increased left ventricular mass, and albuminuria were evaluated. Of 81 patients, 38 (46.9%) were classified as having MHT and showed significantly more SCIs (mean +/- SE: 2.5+/-0.5 vs 1.1+/-0.2; P=.017), and more albuminuria (39% vs 16%; P=.025), but no increase in left ventricular mass index, than the normotensive persons in office and on ambulatory BP monitoring group. The prevalence of MHT in this diabetic population was high (47%). Diabetic patients with MHT showed evidence of brain and kidney damage. Hence, out-of-office monitoring of BP may be indicated in diabetics whose BP is normal in the clinic.     

White-coat hypertension as a risk factor for the development of home hypertension: the Ohasama study

BACKGROUND: White-coat hypertension is a condition characterized by elevated blood pressure (BP) in medical settings combined with normal ambulatory-recorded BP or self-measured BP at home (home BP). However, it is unknown whether this condition represents a transient state in the development of hypertension outside medical settings. METHODS: We followed up 128 subjects with white-coat hypertension (home BP <135/85 mm Hg and office BP > or = 140/90 mm Hg) for 8 years and compared the risk of progression with home hypertension (home BP > or = 135/85 mm Hg or start of treatment with antihypertensive medication) with 649 sustained normotensive subjects (home BP <135/85 mm Hg and office BP <140/90 mm Hg) using data from population-based home BP measurement projects in Japan. RESULTS: During the 8-year follow-up period, 60 subjects (46.9%) with white-coat hypertension and 144 (22.2%) with sustained normotension progressed to home hypertension. The odds ratio of subjects with white-coat hypertension for progression to home hypertension (adjusted for possible confounding factors) was significantly higher than for subjects with sustained normotension (odds ratio, 2.86; P<.001). This association was observed independent of baseline home BP levels. CONCLUSION: The results from the present 8-year follow-up study demonstrate that white-coat hypertension is a transitional condition to hypertension outside medical settings, suggesting that white-coat hypertension may carry a poor cardiovascular prognosis.     

Masked hypertension and target organ damage in treated hypertensive patients

BACKGROUND: Recent studies have shown that an elevated ambulatory or home blood pressure (BP) in the absence of office BP-a phenomenon called masked hypertension-is associated with poor cardiovascular prognosis. However, it remains to be elucidated how masked hypertension modifies target organ damage in treated hypertensive patients. METHODS: A total of 332 outpatients with chronically treated essential hypertension were enrolled in the present study. Patients were classified into four groups according to office (<140/90 or >or=140/90 mm Hg) and daytime ambulatory (<135/85 or >or=135/85 mm Hg) BP levels; ie, controlled hypertension (low office and ambulatory BP), white-coat hypertension (high office but low ambulatory BP), masked hypertension (low office but high ambulatory BP), and sustained hypertension (high office and ambulatory BP). Left ventricular mass index, carotid maximal intima-media thickness, and urinary albumin levels were determined in all subjects. RESULTS: Of the patients, 51 (15%), 65 (20%), 74 (22%), and 142 (43%) were identified as having controlled hypertension, white-coat hypertension, masked hypertension, and sustained hypertension, respectively. Left ventricular mass index, maximal intima-media thickness, and urinary albumin level in masked hypertension were significantly higher than in controlled hypertension and white-coat hypertension, and were similar to those in sustained hypertension. Multivariate regression analyses revealed that the presence of masked hypertension was one of the independent determinants of left ventricular hypertrophy, carotid atherosclerosis, and albuminuria. CONCLUSIONS: Our findings indicate that masked hypertension is associated with advanced target organ damage in treated hypertensive patients, comparable to that in cases of sustained hypertension.     

Cardiovascular outcome in treated hypertensive patients with responder, masked, false resistant, and true resistant hypertension

BACKGROUND: The aim of this study was to evaluate the cardiovascular outcome in apparently responder hypertensive patients with responder and masked hypertension, and in apparently resistant hypertensive patients with false and true resistant hypertension. METHODS: The occurrence of fatal and nonfatal cardiovascular events was evaluated in 340 patients with responder hypertension (clinic blood pressure [BP] <140/90 mm Hg and daytime BP <135/85 mm Hg), 126 with masked hypertension (clinic BP <140/90 mm Hg and daytime BP >135 or 85 mm Hg), 146 with false resistant hypertension (clinic BP >or=140 or 90 mm Hg and daytime BP <135/85 mm Hg), and 130 with true resistant hypertension (clinic BP >or=140 or 90 mm Hg and daytime BP >135 or 85 mm Hg). RESULTS: During follow-up period (4.98 +/- 2.9 years), the event-rate per 100 patient-years was 0.87, 2.42, 1.2, and 4.1 in patients with responder, masked, false resistant, and true resistant hypertension, respectively. After adjustment for several covariates, including clinic BP (forced into the model), Cox regression analysis showed that cardiovascular risk was significantly higher in masked hypertension (masked versus responder hypertension, relative risk [RR] 2.28, 95% confidence interval [CI] 1.1-4.7, P < .05) and in true resistant hypertension (true resistant versus responder hypertension, RR 2.94, 95% CI 1.02-8.41, P < .05), whereas there was no significant difference between false resistant and responder hypertension. CONCLUSIONS: This study shows that patients with masked hypertension are at higher risk than those with responder hypertension, and that those with false resistant hypertension are at lower risk than those with true resistant hypertension. Ambulatory BP monitoring should be performed in treated hypertensive patients to obtain a better prognostic stratification.     

Prognostic relevance of masked hypertension in subjects with prehypertension

BackgroundThe prognostic impact of masked hypertension is not yet completely clear. The aim of this study was to evaluate the prognostic relevance of masked hypertension in subjects with prehypertension.MethodsThe occurrence of fatal and nonfatal cardiovascular events was evaluated in 591 subjects with prehypertension defined as clinic blood pressure (BP) in the range of 120-139 mm Hg for systolic BP and 80-89 mm Hg for diastolic BP. Among them, 471 were classified as having true prehypertension (clinic BP <140/90 mm Hg and daytime BP <135/85 mm Hg) and 120 as having masked hypertension (clinic BP <140/90 mm Hg and daytime BP >/=135 or 85 mm Hg).ResultsDuring the follow-up (6.6 +/- 4.3 years, range 0.5-15.5 years), 29 cardiovascular events occurred. In subjects with true prehypertension and masked hypertension the event-rates per 100 patient-years were 0.57 and 1.51, respectively. Event-free survival was significantly different between the groups (P < 0.005). After adjustment for other covariates, including clinic BP (forced into the model), Cox regression analysis showed that cardiovascular risk was significantly higher in masked hypertension than in true prehypertension (masked vs. true prehypertension, relative risk 2.65, 95% confidence interval 1.18-5.98, P = 0.018).ConclusionsAmong subjects with prehypertension, those with masked hypertension are at higher cardiovascular risk than those with true prehypertension. Out-of-office BP should be known in individuals with prehypertension, preferably by ambulatory BP monitoring or alternatively by home BP measurement, to obtain a better prognostic stratification.American Journal of Hypertension (2008). doi:10.1038/ajh.2008.196American Journal of Hypertension (2008); 21, 8, 879-883. doi:10.1038/ajh.2008.196.     

Masked hypertension in elderly managerial employees and retirees

Masked hypertension is reported to have the same level of hazard risk of cardiovascular mortality and stroke morbidity as sustained hypertension. The number of managerial employees suffering from cardiovascular disease and stroke is known to be greater than other employee. The aim of this study was to compare the 24-h blood pressure (BP) recordings between elderly male managerial employees and retirees and to propose a strategy for identifying masked hypertension. A total of 38 males (16 managerial employees aged 50-69 years and 22 retirees aged 60-65 years) who were not taking any antihypertensive medications participated in this study. Their 24-h BP was measured by an ambulatory BP monitoring device. Daytime (9:00-17:00 h) BPs of the employees (mean, 139/92 mm Hg) were significantly higher than in the retirees (mean 124/80 mm Hg), while there was no difference in BP before and during sleep. In all, 5 of 16 employees (31%) who were diagnosed as normotensive (<140/90 mm Hg) at a periodic health check had hypertension (>135/85 mm Hg) in the morning measured by ambulatory BP monitoring, while 6 (38%) had a similar level of hypertension during the daytime (9:00-17:00 h). These individuals were diagnosed as having masked hypertension. Multiple regression analyses showed that the job was the only factor that contributed to the difference in BP in the subjects during the daytime. This finding suggested that job stress seemed to be one of the main causes of masked hypertension. We argue that more frequent measurements of BP at the work place are necessary to identify subjects with masked hypertension.     

White-coat hypertension: a clinical review

White-coat hypertension (WCHT), also called 'isolated office or clinic hypertension', is defined as the occurrence of blood pressure (BP) values higher than normal when measured in the medical environment, but within the normal range during daily life, usually defined as average daytime ambulatory BP (ABP) or home BP values (<135 mm Hg systolic and <85 mm Hg diastolic). The prevalence of WCHT varies from 15% to over 50% of all patients with mildly elevated office BP (OBP) values. In untreated hypertensive patients, the probability of WCHT especially increases with female gender and a mildly elevated OBP level. The value of other possible determinants such as (non) smoking status, duration of hypertension, left ventricular mass, number of OBP measurements, educational level, etc. is less consistently shown. Although, for various reasons, studies evaluating the long-term effects of WCHT are not always easy to interpret, most data indicate that persons with WCHT have a worse or equal cardiovascular prognosis than normotensives, but a better one than those with sustained hypertension. WCHT is sometimes considered a prehypertensive state, but data on the long-term evolution of subjects with WCHT are scarce. Patients with WCHT and a high cardiovascular risk or proven target organ damage should be pharmacologically treated. Subjects with uncomplicated WCHT should probably not receive medical therapy, but a close follow-up, including regular assessment of other risk factors and measurement of OBP (every 6 months) and ABP (every 1 or 2 years), is warranted.     

Diagnostic criteria of white coat hypertension (WCH): consequences for the implications of WCH for target organs

In a sample comprising 51 normotensive subjects and 51 subjects with in-clinic arterial hypertension [blood pressures (BPs) > or = 140/90 mmHg), we investigated the prevalence of target organ damage [left ventricular hypertrophy (LVH) and retinal vasculopathy] in white coat hypertension (WCH) groups defined using: (a) the "optimal ambulatory BP" criterion of the Seventh International Consensus Conference (in-clinic BPs >140/90 mmHg, daytime mean BPs < 130/80 mmHg) and (b) the "normal ambulatory BP" criterion proposed in 1997 by Verdecchia and co-workers (in-clinic BPs >140/ 90 mmHg, daytime mean BPs < 135/85 mmHg), and we compared the results with those obtained for the normotensive group and for a WCH group defined as in a 1996 study of the same data. We found that the newer criteria did not alter the conclusions reached in 1996: namely, that WCH constitutes a state of risk intermediate between normotension and sustained hypertension, which demands in-depth evaluation and active monitoring, if not immediate therapy. We also found that when the WCH group was defined as those patients with in-clinic BPs > or = 140/90 mmHg and 24-h mean BPs < 121/78 mmHg, the prevalence of target organ damage was similar to that found in the control group. We conclude that if WCH status is to imply absence of elevated risk of target organ damage, then the ambulatory BP threshold defining WCH should be lower than the upper limit of ambulatory BPs among subjects who are normotensive in the clinic. The desirability of predicting target organ damage in both hypertensive and normotensive subjects using criteria combining in-clinic BPs, daytime mean ambulatory BPs and night-time mean ambulatory BPs is suggested.     

White coat hypertension and pregnancy outcome.

The presence and outcome effect of white coat hypertension in pregnancy was determined with 24-h ambulatory blood pressure (BP) monitoring. Sixty women presenting with high clinic BP (>/=140/90 mm Hg) in the second trimester were included. Patients were divided into two groups based on daytime ambulatory BP findings: <135/85 mm Hg, white coat hypertension (n = 37); >/=135/85 mm Hg, 'true' hypertension (n = 23). Complicated pregnancy outcome was defined as the presence of pre-eclampsia and/or intrauterine growth restriction. Groups were compared for pregnancy outcome and for background and delivery factors. The predictive value of ambulatory BP measurements for pregnancy outcome was determined. Pregnancy outcome was better in the white coat hypertension group than in the true hypertension group: pre-eclampsia-3 (8.1%) vs 13 (56.5%) (P = 0.0046); intrauterine growth restriction-5 (13.5%) vs 10 (43.4%) (P = 0. 0139); and preterm delivery-11 (29.7%) vs 15 (65.2%) (P = 0.015). Night-time ambulatory BP measurements were the best predictor of complicated pregnancy, followed by daytime and 24-h measurements. We conclude that second trimester ambulatory BP monitoring can be used to differentiate patients who have white coat hypertension, which is associated with a better pregnancy outcome than true hypertension.     

How well do office and exercise blood pressures predict sustained hypertension? A Dundee Step Test Study

Exercise systolic blood pressure (BP) appears to be a better predictor of cardiac mortality than casual office BP. We tested whether this could be explained by exercise systolic BP being a better predictor of sustained hypertension than casual office BP. Exercise systolic BP was measured using the lightweight 3-min single stage, submaximal Dundee Step Test in 191 consecutive subjects (102 male, age 52 (s.d. 13) years) who were referred to a specialist hypertension clinic for assessment. Exercise systolic BP was compared with office BP and daytime ambulatory BP (ABP). Sustained hypertension was defined as a mean daytime systolic and/or diastolic ABP of >/=140/90 mm Hg. Receiver operating characteristic (ROC) curves of exercise systolic BP and office BP in predicting sustained hypertension were compared. The positive predictive value of office diastolic BP >/=90 mm Hg and office systolic BP >/=140 mm Hg for sustained hypertension were 64% and 67% respectively. However, exercise systolic BP >/=180 mm Hg had a positive predictive value of 76%. Twenty-two percent (42/191) of subjects had an exercise systolic BP rise to >/=210 mm Hg, and 93% of this group had sustained hypertension on ABP. Whilst exercise systolic BP was a better predictor of sustained hypertension using currently recommended office BP treatment thresholds, the ROC curves of these indices were not different. In a multiple regression analysis, exercise systolic BP was an independent predictor of sustained hypertension, accounting for 36% of the variance of daytime systolic ABP after adjusting for age, gender and antihypertensive drug treatment. In conclusion, exercise systolic BP was a marginally better predictor of sustained hypertension than office BP. This may partly explain why exercise systolic BP is a potent predictor of cardiac mortality.     

Relationship between aortic stiffness and cardiovascular risk factors in a population of normotensives, white-coat normotensives, white-coat hypertensives, sustained hypertensives and diabetic patients.

OBJECTIVE: To evaluate the relationship between carotid-femoral pulse wave velocity (PWV) and office and ambulatory blood pressure (ABP) and other cardiovascular risk factors and to determine the discriminatory value of PWV in a large population including normotensive subjects (NT), white-coat normotensives (masked hypertension) (WCNT), and white-coat hypertensives (WCHT) compared to a group of treated and untreated hypertensive patients. METHODS: The study population included a total of 688 subjects aged from 18 to 80 years, with no previous cardiovascular events, who underwent 24 h ABP monitoring, biochemical evaluation and determination of PWV and left ventricular mass index (LVMI). Subjects were classified as true normotensives (NT, n=132; normal office and ABP values), WCNT (n=39; office BP < 140/90 and daytime BP > or =135 or > or =85 mmHg), WCHT (n=87; office BP > or =140 or > or =90 and daytime BP < 135/85 mmHg). Untreated (UT-HT, n=154) and treated (T-HT, n=171) hypertensive patients and type 2 diabetic patients (DM, n=102) were also studied. RESULTS: Values of PWV (m/s) in all groups were, in ascending order: NT (8.9 +/- 0.2) < WCHT (9.9 +/- 0.2) < T-HT (11.4 +/- 0.2) = WCNT (11.5 +/- 0.4) < UT-HT (11.9 +/- 0.3) < DM (12.6 +/- 0.4) (ANOVA, p = 0.043), and of LVMI (g/m2): NT (59 +/- 2) = WCHT (63 +/- 2) < WCNT (73 +/- 3) = T-HT (75 +/- 3) = UT-HT (77 +/- 3) < DM (84 +/- 4) (ANOVA, p < 0.05). The percentage of subjects with PWV values below the median (10.7 m/s) was higher (p < 0.02) in NT (81.8%) and WCHT (72.6%) than in UT-HT (49.2%), T-HT (43.6%), WCNT (47.6%) and DM (27.7%). In multiple regression analysis, taking PWV as the dependent variable, age (all groups), 24h systolic BP (UT-HT, T-HT, WCNT and DM) and 24h diastolic BP (NT and WCHT) were the variables that independently influenced the PWV value. CONCLUSIONS: Higher values of PWV occur in clinical situations associated with higher cardiovascular risk. This is in agreement with risk stratification based on ABP values but not on office BP values. Lower PWV and LVMI values occur in NT and WCHT subjects, supporting a low cardiovascular risk in these groups. By contrast, higher PWV values were associated with higher ABP values in DM, hypertensive patients and white-coat normotensives, i.e. clinical situations that are associated with higher cardiovascular risk, who in the present study also exhibited higher LVMI than subjects with normal ABP values.     

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

OBJECTIVE: We investigated to what extent anthropometric and lifestyle factors contributed to the classification of Chinese individuals into groups with white-coat, masked and sustained hypertension (HT). METHODS: We measured the office and ambulatory blood pressure (BP) in 694 Chinese enrolled in the JingNing population study (45.7% men; mean age, 48.4 years). In multivariate-adjusted analyses, we determined the correlates of both types of BP and the factors contributing to white-coat HT (conventional and daytime BP > or =140/90 and <135/85 mmHg, respectively), masked HT (<140/90 and > or =135/85 mmHg) and sustained HT (> or =140/90 and > or =135/85 mmHg), relative to normotension (<140/90 and <135/85 mmHg). RESULTS: In continuous analyses, the conventional and daytime BPs were positively associated with age, body mass index and urinary sodium, and inversely with urinary potassium. The prevalence of white-coat, masked and sustained HT was 7.8, 10.8, and 35.0%, respectively. In line with the continuous analyses, the risk of sustained hypertension increased with age [odds ratio (OR), 2.11 per 10 years], body mass index (OR, 1.27 per 1 kg/m2) and urinary sodium (OR, 1.18 per 50 mmol/day), but was inversely associated with urinary potassium (OR, 0.34 per 25 mmol/day). Furthermore, the risk of white-coat and masked HT increased with age (OR, 1.79 and 1.40, respectively) and body mass index (OR, 1.14 and 1.12). Women were less likely to have masked hypertension than men (OR, 0.39). CONCLUSIONS: Sex, age, body mass index, and urinary sodium and potassium excretion contribute to the risk of white-coat, masked and sustained HT in Chinese.     

Metabolic syndrome and masked hypertension among African Americans: The Jackson Heart Study

The metabolic syndrome is associated with higher ambulatory blood pressure. The authors studied the association of metabolic syndrome and masked hypertension (MHT) among African Americans with clinic‐measured systolic/diastolic blood pressure (SBP/DBP) <140/90 mm Hg in the Jackson Heart Study. MHT was defined as daytime, nighttime, or 24‐hour hypertension on ambulatory blood pressure monitoring. Among 359 participants not taking antihypertensive medication, the metabolic syndrome was associated with MHT (prevalence ratio, 1.38; 95% confidence interval, 1.10–1.74]). When metabolic syndrome components (clinic SBP/DBP 130–139/85–89 mm Hg, abdominal obesity, impaired glucose, low high‐density lipoprotein cholesterol, high triglycerides) were analyzed separately, only clinic SBP/DBP 130–139/85–89 mm Hg was associated with MHT (prevalence ratio, 1.90; 95% confidence interval, 1.56–2.32]). The metabolic syndrome was not associated with MHT among participants not taking antihypertensive medication with SBP/DBP 130–139/85–89 and <130/85 mm Hg, separately, or among participants taking antihypertensive medication (n=393). Ambulatory blood pressure monitoring screening for MHT among African Americans should be considered based on clinic BP, not metabolic syndrome.     

Masked Hypertension in Elderly Managerial Employees and Retirees

Masked hypertension is reported to have the same level of hazard risk of cardiovascular mortality and stroke morbidity as sustained hypertension. The number of managerial employees suffering from cardiovascular disease and stroke is known to be greater than other employee. The aim of this study was to compare the 24-h blood pressure (BP) recordings between elderly male managerial employees and retirees and to propose a strategy for identifying masked hypertension. A total of 38 males (16 managerial employees aged 50–69 years and 22 retirees aged 60–65 years) who were not taking any antihypertensive medications participated in this study. Their 24-h BP was measured by an ambulatory BP monitoring device. Daytime (9:00–17:00 h) BPs of the employees (mean, 139/92 mm Hg) were significantly higher than in the retirees (mean 124/80 mm Hg), while there was no difference in BP before and during sleep. In all, 5 of 16 employees (31%) who were diagnosed as normotensive (<140/90 mm Hg) at a periodic health check had hypertension (>135/85 mm Hg) in the morning measured by ambulatory BP monitoring, while 6 (38%) had a similar level of hypertension during the daytime (9:00–17:00h). These individuals were diagnosed as having masked hypertension. Multiple regression analyses showed that the job was the only factor that contributed to the difference in BP in the subjects during the daytime. This finding suggested that job stress seemed to be one of the main causes of masked hypertension. We argue that more frequent measurements of BP at the work place are necessary to identify subjects with masked hypertension.