Impact of prehypertension on carotid artery intima–media thickening: Actual or masked?

Association of prehypertension and hyperhomocysteinemia with subclinical atherosclerosis in asymptomatic Chinese: a cross-sectional study

OBJECTIVES

Comorbid hypertension and hyperhomocysteinemia is an important risk factor for carotid atherosclerotic plaque formation. We put forward the hypothesis that the subjects with comorbid prehypertension and hyperhomocysteinemia also had an increased risk of subclinical atherosclerosis, using carotid intima-media thickness (CIMT) as the marker of the atherosclerotic process.

METHODS

A total of 4102 asymptomatic Chinese subjects aged 18-60 years were divided into four groups according to blood pressure (BP) and homocysteine (HCY) level: the control group without prehypertension or hyperhomocysteinemia, isolated prehypertension group, simple hyperhomocysteinemia group and prehypertension with hyperhomocysteinemia group. Serum lipids, fasting blood glucose (FBG), HCY and CIMT were measured.

RESULTS

There was significant difference in the positive rates of increased CIMT among four groups. Compared with the controls, the subjects in the other three groups had a higher risk of increased CIMT (isolated prehypertension group, OR 2.049, 95% CI 1.525 to 2.754; simple hyperhomocysteinemia group, OR 2.145, 95% CI 1.472 to 3.125; prehypertension and hyperhomocysteinemia group, OR 3.199, 95% CI 2.362 to 4.332). However, by multiple logistic regression analysis, only comorbid prehypertension and hyperhomocysteinemia was independently associated with increased CIMT (OR 1.485, 95% CI 1.047 to 2.108, P<0.05).

CONCLUSIONS

Comorbid prehypertension and hyperhomocysteinemia was an independent risk factor of subclinical atherosclerosis in asymptomatic Chinese, but isolated prehypertension or hyperhomocysteinemia was not. Therefore, combined intervention for prehypertension and hyperhomocysteinemia may contribute to decrease the incident of cardiovascular disease.

Intima-Media Thickness Is Linearly and Continuously Associated With Systolic Blood Pressure in a Population-Based Cohort (STANISLAS Cohort Study)

BACKGROUND

Carotid intima-media thickness (cIMT) is a noninvasive marker of cardiovascular risk. The cIMT may be increased in patients with harmonisation, but little is known regarding the functional form of the association between blood pressure (BP) and cIMT in hypertensive and nonhypertensive persons. We aimed to define the shape of the association between BP and cIMT.

METHODS AND RESULTS

We studied cIMT and ambulatory BP monitoring data from a single-center, cross-sectional, population-based study involving 696 adult participants from the STANISLAS cohort, a familial longitudinal cohort from the Nancy region of France. Participants with a history of hypertension were more likely to have a cIMT >900 μm and had higher mean cIMT (both P<0.001). The risk of cIMT >900 μm increased linearly with higher 24-hour and daytime systolic BP in participants both with and without history of hypertension. The relationship between systolic BP and the risk of cIMT >900 μm was not dependent on hypertension status (all P for interaction >0.10). In multivariable analysis adjusted on cardiovascular risk factors, each 5-mm Hg increase in systolic BP was associated with an 8-μm increase in cIMT (β=8.249 [95% CI 2.490-14.008], P=0.005). In contrast, the association between diastolic BP and cIMT was weaker and not significant.

CONCLUSIONS

Systolic BP is linearly and continuously associated with higher cIMT in both hypertensive and nonhypertensive persons, suggesting a detrimental effect of BP on the vascular tree prior to overt hypertension. Similarly, it suggests a detrimental effect of BP at the higher end of the normal range in treated hypertensive patients.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov/. Unique identifier: NCT01391442.

Evaluation of prehypertension and masked hypertension rate among clinically normotensive patients

BACKGROUND

The present cross-sectional study was aimed to identify pre-hypertension and masked hypertension rate in clinically normotensive adults in relation to socio-demographic, clinical and laboratory parameters.

METHODS

A total of 161 clinically normotensive adults with office blood pressure (OBP) <140/90 mmHg without medication were included in this single-center cross-sectional study. OBP, home BP (HBP) recordings and ambulatory BP monitoring (ABPM) were used to identify rates of true normotensives, true pre-hypertensives and masked hypertensives. Data on sociodemographic and clinical characteristics were collected in each subject and evaluated with respect to true normotensive vs. pre-hypertensive patients with masked hypertension or true pre-hypertensive. Target organ damage (TOD) was evaluated in masked hypertensives based on laboratory investigation.

RESULTS

Masked hypertension was identified in 8.7% of clinically normotensives. Alcohol consumption was significantly more common in masked hypertension than in true pre-hypertension (28.6 vs. 0.0%, p = 0.020) with risk ratio of 2.7 (95% CI 1.7-4.4). Patients with true pre-hypertension and masked hypertension had significantly higher values for body mass index, waist circumference, systolic and diastolic OBP and HBP (p < 0.05 for each) compared to true normotensive subjects. ABPM revealed significantly higher values for day-time and night-time systolic and diastolic BP (p = 0.002 for night-time diastolic BP, p < 0.001 for others) in masked hypertension than true pre-hypertension.

CONCLUSIONS

Given that the associations of pre-hypertension with TOD might be attributable to the high prevalence of insidious presentation of masked hypertension among pre-hypertensive individuals, ABPM seems helpful in early identification and management of masked hypertension in the pre-hypertensive population.

Untreated masked hypertension and carotid atherosclerosis: a meta-analysis

AIM

Masked hypertension (MH) is recognized as a clinical entity with an unfavorable cardiovascular prognosis; a limited number of reports, however, investigated the impact of this condition on subclinical vascular damage. We performed a meta-analysis aimed at evaluating the association of MH with subclinical carotid atherosclerosis in initially untreated subjects.

DESIGN

Studies were identified by the following search terms: "masked hypertension", "isolated clinic normotension", "white coat normotension", "carotid artery", "carotid atherosclerosis", "carotid intima-media thickness", "carotid damage" and "carotid thickening". Full articles published in English language reporting data from studies performed in untreated adult individuals were considered.

RESULTS

Overall, 2752 untreated subjects (1039 normotensive, 497 MH and 766 hypertensive individuals) of both genders were included in five studies (sample size range 18-222 for MH participants). Common carotid intima-media thickness (IMT) showed a progressive increase from normotensive (681 ± 24 μm) to MH (763 ± 57 μm) (standardized mean difference, SMD: 0.51 ± 0.19, 95% CI 0.13-0.89, p < 0.01) and to sustained hypertensive subjects (787 ± 58 μm) (SMD: 0.33 ± 0.07, 95% CI 0.20-0.46, p < 0.01). The statistical difference between MH and NT became borderline after correction for publication bias. A sensitivity analysis showed that the final result was not substantially affected by a single study effect.

CONCLUSIONS

Our findings support the view that MH subjects tend to have a higher risk of developing early carotid atherosclerosis than their true normotensive counterparts. From a practical perspective, the ultrasound search of preclinical carotid disease may improve cardiovascular risk stratification and decision making strategies in these subjects.

Risk stratification by ambulatory blood pressure monitoring across JNC classes of conventional blood pressure

BACKGROUND

Guidelines propose classification of conventional blood pressure (CBP) into normotension (<120/<80 mm Hg), prehypertension (120-139/80-89 mm Hg), and hypertension (≥140/≥90 mm Hg).

METHODS

To assess the potential differential contribution of ambulatory blood pressure (ABP) in predicting risk across CBP strata, we analyzed outcomes in 7,826 untreated people recruited from 11 populations.

RESULTS

During an 11.3-year period, 809 participants died (276 cardiovascular deaths) and 639, 383, and 225 experienced a cardiovascular, cardiac, or cerebrovascular event. Compared with normotension (n = 2,639), prehypertension (n = 3,076) carried higher risk (P ≤ 0.015) of cardiovascular (+41%) and cerebrovascular (+92%) endpoints; compared with hypertension (n = 2,111) prehypertension entailed lower risk (P ≤ 0.005) of total mortality (-14%) and cardiovascular mortality (-29%) and of cardiovascular (-34%), cardiac (-33%), or cerebrovascular (-47%) events. Multivariable-adjusted hazard ratios (HRs) for stroke associated with 24-hour and daytime diastolic ABP (+5 mm Hg) were higher (P ≤ 0.045) in normotension than in prehypertension and hypertension (1.98 vs.1.19 vs.1.28 and 1.73 vs.1.09 vs. 1.24, respectively) with similar trends (0.03 ≤ P ≤ 0.11) for systolic ABP (+10 mm Hg). However, HRs for fatal endpoints and cardiac events associated with ABP did not differ significantly (P ≥ 0.13) across CBP categories. Of normotensive and prehypertensive participants, 7.5% and 29.3% had masked hypertension (daytime ABP ≥135/≥85 mm Hg). Compared with true normotension (P ≤ 0.01), HRs for stroke were 3.02 in normotension and 2.97 in prehypertension associated with masked hypertension with no difference between the latter two conditions (P = 0.93).

CONCLUSION

ABP refines risk stratification in normotension and prehypertension mainly by enabling the diagnosis of masked hypertension.

Target organ damage and masked hypertension in the general population: the Finn-Home study

BACKGROUND

The relation of masked hypertension to target organ damage has very seldom been investigated in a general population.

METHODS

An unselected population cohort (n = 1989 of which 1540 were not treated for hypertension) underwent office (duplicate measurements on one visit by a nurse) and home (duplicate measurements on 7 days) blood pressure (BP) measurements and evaluation of electrocardiographic left ventricular hypertrophy (ECG-LVH, n = 1989/1540), carotid intima-media thickness (cIMT, n = 758/592), and pulse wave velocity (PWV, n = 237/158). ECG-LVH was diagnosed using Cornell voltage criteria. PWV was measured using whole-body impedance cardiography. Masked hypertension was defined as office BP less than 140/90 mmHg with home BP at least 135/85 mmHg and white-coat hypertension as office BP at least 140/90 mmHg and home BP less than 135/85 mmHg.

RESULTS

Masked and sustained hypertensive individuals had significantly higher age-adjusted and sex-adjusted Cornell voltage, cIMT, and PWV than normotensive individuals. White-coat hypertensive patients had higher age-adjusted and sex-adjusted Cornell voltage than normotensive individuals but significantly lower Cornell voltage and PWV than sustained hypertensive patients. The differences in Cornell voltage and PWV remained significant after adjustment for confounding factors. However, all differences became nonsignificant after adjustment for systolic home BP.

CONCLUSION

Masked and sustained hypertension is accompanied by increased risk for hypertensive target organ damage, whereas white-coat hypertension seems to be a more benign phenomenon.

Endothelial wall thickness, cardiorespiratory fitness and inflammatory markers in obese and non-obese adolescents

BACKGROUND

Increased carotid intima-media thickness (c-IMT) is considered a marker of early-onset atherosclerosis and it has been found in obese children and adolescents, but the risk factors associated with this population remain to be elucidated.

OBJECTIVE

To compare and verify the relationship between c-IMT, metabolic profile, inflammatory markers, and cardiorespiratory fitness in obese and non-obese children and adolescents.

METHOD

Thirty-five obese subjects (19 boys) and 18 non-obese subjects (9 boys), aged 10-16 years, were included. Anthropometry, body composition, blood pressure, maximal oxygen consumption (VO2max), and basal metabolic rate were evaluated. Serum glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), blood lipids, C-reactive protein (CRP), and adiponectin were assessed. c-IMT was measured by ultrasound.

RESULTS

The results showed that c-IMT, triglycerides, insulin, HOMA-IR, and CRP values were significantly higher in the obese group than in the non-obese group, and high-density lipoprotein cholesterol (HDL-c), adiponectin, and VO2max values were significantly lower in the obese group than in the non-obese group. The c-IMT was directly correlated with body weight, waist circumference, % body fat, and HOMA-IR and inversely correlated with % free fat mass, HDL-c, and VO2max.

CONCLUSIONS

Our findings show that c-IMT correlates not only with body composition, lipids, insulin resistance, and inflammation but also with low VO2max values in children and adolescents.

Endothelial-dependent flow-mediated dilation in African Americans with masked-hypertension

BACKGROUND

Office-blood pressure (BP) measurements alone overlook a significant number of individuals with masked-hypertension (office-BP: 120/80-139/89 mm Hg and 24-h ambulatory BP monitoring (ABPM) daytime ≥135/85 mm Hg or night-time ≥120/70 mm Hg). Diminished endothelial function contributes to the pathogenesis of hypertension. To better understand the pathophysiology involved in the increased cardiovascular (CV) disease risk associated with masked-hypertension, we estimated the occurrence, assessed the endothelial function, compared plasma levels of inflammatory markers, white blood cell count (WBC count), tumor necrosis factor-α (TNF-α), and high sensitivity C-reactive protein (hsCRP) and examined the possible relationship between endothelial function and inflammatory markers in apparently healthy prehypertensive (office-BP: 120/80-139/89 mm Hg) African Americans.

METHODS

Fifty African Americans who were sedentary, nondiabetic, nonsmoking, devoid of CV disease were recruited. Office-BP was measured according to JNC-7 guidelines to identify prehypertensives in whom ABPM was then assessed. Fasting plasma samples were assayed for inflammatory markers. Brachial artery flow-mediated dilation (FMD) at rest and during reactive hyperemia was measured in a subset of prehypertensives.

RESULTS

Subjects in the masked-hypertension sub-group had a higher hsCRP (P = 0.04) and diminished endothelial function (P = 0.03) compared to the true-prehypertensive sub-group (office-BP: 120/80-139/89 mm Hg and ABPM: daytime <135/85 mm Hg or night-time <120/70 mm Hg). Regression analysis showed that endothelial function was inversely related to hsCRP amongst the masked-hypertensive sub-group (R(2) = 0.160; P = 0.04).

CONCLUSIONS

Masked-hypertension was identified in 58% of African Americans which suggests that a masking phenomenon may exist in a sub-group of prehypertensives who also seem to have a diminished endothelial function that could be mediated by an elevated subclinical inflammation leading to the increased CV disease.