Estimate of white-coat effect and arterial stiffness

Hypertension in an ageing population: Diagnosis, mechanisms, collateral health risks, treatments, and clinical challenges

Ageing population is considerably increasing worldwide, which is considered to reflect an improved quality of life. However, longevity in the human lifespan has increased the burden of late-life illnesses including cancer, neurodegeneration, and cardiovascular dysfunction. Of these, hypertension is the most common condition with huge health risks, with an increased prevalence among the elderly. In this review, we outline the current guidelines for defining hypertension and examine the detailed mechanisms underlying the relationship between hypertension and ageing-related outcomes, including sodium sensitivity, arterial stiffness, endothelial dysfunction, isolated systolic hypertension, white coat effect, and orthostatic hypertension. As hypertension-related collateral health risk increases among the elderly, the available management strategies are necessary to overcome the clinical treatment challenges faced among elderly population. To improve longevity and reduce adverse health effects, potential approaches producing crucial information into new era of medicine should be considered in the prevention and treatment of hypertension among elderly population. This review provides an overview of mechanisms underlying hypertension and its related collateral health risk in elderly population, along with multiple approaches and management strategies to improve the clinical challenges among elderly population.

The effects of experimental, meteorological, and physiological factors on short-term repeated pulse wave velocity measurements, and measurement difficulties: A randomized crossover study with two devices

Background

Large longitudinal studies with repeated pulse wave velocity (PWV) measurements, a direct measure of arterial stiffness, are required to realize the full potential of arterial stiffness in clinical practice. To facilitate such studies it is important to increase the power of a study by reducing within-subject variability of PWV, and to ease the use of a PWV device in clinical settings by minimizing PWV measurement difficulties.

Methods

We systematically investigated experimental setting and meteorological conditions, as well as physiological factors and participant characteristics, to determine whether and to what extent they affected: between- and within-subjects variability of PWV recordings, and measurement difficulties of a particular device. We conducted a 2-week longitudinal block-randomized cross-over study with two blinded observers and two commonly used devices: applanation tonometry SphygmoCor CvMS and oscillometric Arteriograph to assess carotid-femoral (cfPWV) or aortic (PWVao) PWV, respectively. Our sample had uniform and wide-spread distribution of age, blood pressures, hypertensive status and BMI. Each participant (N = 35) was recorded 12 times over 3 visiting days, 7 days apart. On each day, recordings were made twice in the morning (7-10 a.m.) and afternoon (16-18 p.m.). Data were analyzed using multilevel mixed-effects models, separately for each device.

Results

In addition to age and mean arterial pressure (MAP) that strongly affected both cfPWV and PWVao, other significant factors appeared to indicate a measurement approach. cfPWV as a more direct measure of arterial stiffness was additionally affected by hypertension status, outdoor temperature, interaction of MAP with outdoor temperature and the order of visit, with MAP within-subject variability contributing on average 0.27 m/s to difference in repeated measurements at 5^°C and 0.004 m/s at 25^°C. PWVao measurements derived at a single brachial site were more dependent on age than cfPWV and also depended on personal characteristics such as height and sex, and heart rate; with within-subject MAP variability adding on average 0.23 m/s to the difference in repeated measures. We also found that female sex significantly increased, and recording in afternoon vs. morning significantly decreased measurement difficulties of both devices.

Conclusion

We identified factors affecting PWV recordings and measurement-difficulties and propose how to improve PWV measuring protocols.

Relations between white coat effect of blood pressure and arterial stiffness

The aim of this study was to analyze the relationship between brachial-ankle pulse wave velocity (b-a PWV) and white coat effect (WCE), that is the difference between the elevated office blood pressure (BP) and the lower mean daytime pressure of ambulatory BP, in a mixed population of normotention, untreated sustained hypertension, sustained controlled hypertension, sustained uncontrolled hypertension, white coat hypertension, white coat uncontrolled hypertension. A total of 444 patients with WCE for systolic BP (54.1% female, age 61.86 ± 13.3 years) were enrolled in the study. Patients were separated into low WCE (<9.5 mm Hg) and high WCE (≥9.5 mm Hg) according to the median of WCE. The subjects with a high WCE showed a greater degree of arterial stiffness than those with a low WCE for systolic BP values (P < .05). The b-a PWV were 17.2 ± 3.3 m/s and 18.4 ± 3.4 m/s in low WCE and high WCE, respectively. The b-a PWV increased with the increase of WCE, showing a positive correlation between them (P > .05 for non-linearity). The significant association between the high WCE and the b-a PWV was confirmed by the results of multiple regression analysis after adjusting for confounding factors (β = .78, 95% Cl .25-1.31, P = . 004). Similar results were observed in subgroups. In conclusion, WCE is significantly associated with arterial stiffness. More research is needed to determine the WCE and target organ damage.

Home Blood Pressure Compared With Office Blood Pressure in Relation to Dysglycemia

BACKGROUND

Masked hypertension is more common in individuals with type 2 diabetes than in individuals with normoglycemia. We aimed to explore if there is a discrepancy between office blood pressure (office BP) and home blood pressure monitoring (HBPM) in relation to HbA1c as well as glycemic status in 5,029 middle-aged individuals.

METHODS

HBPM was measured in a subsample of 5,029 participants in The Swedish CardioPulmonary BioImage Study (SCAPIS), a population-based cohort of 50-64 years old participants. Both office BP and HBPM were obtained after 5 minutes' rest using the semiautomatic Omron M10-IT oscillometric device. White coat effect was calculated by subtracting systolic HBPM from systolic office BP. Participants were classified according to glycemic status: Normoglycemia, prediabetes, or diabetes based on fasting glucose, HbA1c value, and self-reported diabetes diagnosis.

RESULTS

Of the included 5,025 participants, 947 (18.8%) had sustained hypertension, 907 (18.0%) reported taking antihypertensive treatment, and 370 (7.4%) had diabetes mellitus. Both systolic office BP and HBPM increased according to worsened glycemic status (P for trend 0.002 and 0.002, respectively). Masked hypertension was more prevalent in participants with dysglycemia compared with normoglycemia (P = 0.036). The systolic white coat effect was reversely associated with HbA1c (P = 0.012).

CONCLUSIONS

The systolic white coat effect was reversely associated with HbA1c, and the prevalence of masked hypertension increased with dysglycemia.

Plasma uric acid is related to large arterial stiffness but not to other hemodynamic variables: a study in 606 normotensive and never-medicated hypertensive subjects

Background

Elevated level of plasma uric acid (PUA) has been associated with cardiovascular disease, but whether uric acid is an independent risk factor or merely a marker remains controversial.

Methods

We investigated in a cross-sectional setting the association of PUA with hemodynamics in 606 normotensive and never-medicated hypertensive subjects (295 men, 311 women, age range 19–73 years) without cardiovascular disease or gout. In all except 15 individuals, PUA was within the normal range. Supine hemodynamics were recorded using whole-body impedance cardiography and radial tonometric pulse wave analysis.

Results

The mean concentrations of PUA in age, sex and body mass index adjusted quartiles were 234, 278, 314, and 373 µmol/l, respectively. The highest PUA quartile presented with higher aortic to popliteal pulse wave velocity (PWV) than the lowest quartile (8.7 vs. 8.2 m/s, p = 0.026) in analyses additionally adjusted for plasma concentrations of C-reactive protein, low density lipoprotein cholesterol, triglycerides, and mean aortic blood pressure. No differences in radial and aortic blood pressure, wave reflections, heart rate, cardiac output, and systemic vascular resistance were observed between the quartiles. In linear regression analysis, PUA was an independent explanatory factor for PWV (β = 0.168, p < 0.001, R² of the model 0.591), but not for systolic or diastolic blood pressure. When the regression analysis was performed separately for men and women, PUA was an independent predictor of PWV in both sexes.

Conclusions

PUA concentration was independently and directly associated with large arterial stiffness in individuals without cardiovascular disease and PUA levels predominantly within the normal range. Trial registration ClinicalTrials.gov NCT01742702.

Aldosterone-to-renin ratio is related to arterial stiffness when the screening criteria of primary aldosteronism are not met

Aldosterone-to-renin ratio (ARR) is a screening tool for primary aldosteronism (PA), but the significance of ARR when the PA criteria are not met remains largely unknown. In this cross-sectional study we investigated the association of ARR with haemodynamic variables in 545 normotensive and never-medicated hypertensive subjects (267 men, 278 women, age range 19-72 years) without suspicion of PA. Supine haemodynamic data was recorded using whole-body impedance cardiography and radial tonometric pulse wave analysis. In sex-adjusted quartiles of ARR, determined as serum aldosterone to plasma renin activity ratio, the mean values were 282, 504, 744 and 1467 pmol/µg of angiotensin I/h, respectively. The only difference in haemodynamic variables between the ARR quartiles was higher pulse wave velocity (PWV) in the highest quartile versus other quartiles (p = 0.004), while no differences in blood pressure (BP), heart rate, wave reflections, cardiac output or systemic vascular resistance were observed between the quartiles. In linear regression analysis with stepwise elimination, ARR was an independent explanatory factor for PWV (β = 0.146, p < 0.001, R2 of the model 0.634). In conclusion, ARR was directly and independently associated with large arterial stiffness in individuals without clinical suspicion of PA. Therefore, ARR could serve as a clinical marker of cardiovascular risk.Trial registration: ClinicalTrails.gov: NCT01742702.

White coat syndrome and its variations: differences and clinical impact

Hypertension is closely linked to increased cardiovascular risk and development of target organ damage (TOD). Therefore, proper clinical follow-up and treatment of hypertensive subjects are mandatory. A great number of individuals present a variation on blood pressure (BP) levels when they are assessed either in the office or in the out-of-office settings. This phenomenon is defined as white coat syndrome - a change in BP levels due to the presence of a physician or other health professional. In this context, the term "white coat syndrome" may refer to three important and different clinical conditions: 1) white coat hypertension, 2) white coat effect, and 3) masked hypertension. The development of TOD and the increased cardiovascular risk play different roles in these specific subgroups of white coat syndrome. Correct diagnose and clinical guidance are essential to improve the prognosis of these patients. The aim of this review was to elucidate contemporary aspects of these types of white coat syndrome on general and hypertensive population.

Body weight-dependent relationships between alcohol consumption and pulse pressure in middle-aged Japanese women

High pulse pressure is a risk factor for cardiovascular disease, and excessive alcohol drinking increases the risk of hypertension. The purpose of this study was to elucidate the relationship between alcohol intake and pulse pressure in women and to determine whether body weight influences their relationship. The subjects were 18,791 Japanese middle-aged women, and they were divided into tertile groups for body weight or three different body mass index (BMI, kg/m²) groups (low BMI <22; middle BMI ≥22 and <25; high BMI ≥25). The subjects in each group were further divided into four groups of nondrinkers, occasional drinkers, regular light drinkers, and regular heavy drinkers by habitual alcohol consumption. Pulse pressure levels were compared between nondrinkers and drinkers in each group for body weight or BMI. Pulse pressure was significantly higher in regular heavy drinkers than in nondrinkers in the first tertile group for body weight and in the low BMI group but not in the second and third tertile groups for body weight and in the middle and high BMI groups. In all tertile groups and all BMI groups, pulse pressure was not significantly different in occasional drinkers and regular light drinkers than in nondrinkers. In women with lower body weight, heavy drinking was positively associated with pulse pressure, while this association was not found in women with middle or higher body weight. Thus, body weight potently confounds the relationship between alcohol consumption and pulse pressure.

Arterial Stiffness in Treated Hypertensive Patients With White-Coat Hypertension

Arterial stiffness, assessed through pulse wave velocity (PWV), independently predicts cardiovascular outcomes. In untreated persons, white-coat hypertension (WCH) has been related to arterial stiffness, but data in treated patients with WCH are scarce. The authors aimed to determine a possible association between WCH and arterial stiffness in this population. Adult treated hypertensive patients underwent home blood pressure monitoring and PWV assessment. Variables associated with PWV in univariable analyses were entered into a multivariable linear regression model. The study included 121 patients, 33.9% men, median age 67.9 (interquartile range 18.4) years, 5.8% with diabetes, and 3.3% with a history of cardiovascular or cerebrovascular disease. In multivariable analysis, WCH in treated hypertensive patients remained a determinant of PWV: β=1.1 (95% confidence interval, 0.1-2.1 [P=.037]; adjusted R² 0.49). In conclusion, WCH is independently associated with arterial stiffness in treated hypertensive patients. Whether this high-risk association is offset by antihypertensive treatment should be further investigated.

White-Coat and Reverse White-Coat Effects Correlate with 24-h Pulse Pressure and Systolic Blood Pressure Variability in Children and Young Adults

Masked hypertension (MH) and white-coat hypertension (WCH) are associated with organ damage. In the present study, we examined the correlation between the magnitude of white-coat effect (WCE) or reverse WCE (RWCE) and 24-h pulse pressure (PP), an indicator of target organ damage and arterial stiffness, in children and young adults. We also examined the relationship of WCE or RWCE and blood pressure (BP) variability, another predictor of clinical outcomes. One hundred and ninety-eight subjects were studied. According to the office BP and ambulatory BP, they were divided into normotension, WCH, MH, and hypertension. The magnitude of WCE or RWCE, along with male gender and 24-h systolic BP, was the determinant of 24-h PP. In subjects with 24-h PP ≥ 61 mmHg, the magnitude of WCE or RWCE, age, male ratio, height, weight, BMI, the percentage of secondary hypertension, that of MH, office systolic BP, and 24-h systolic BP were significantly greater. There was a progressive increase in 24-h PP from normotension, WCH, MH, to hypertension. BP variability in subjects with MH was numerically highest in both systolic and diastolic. Diastolic BP variability of WCH, MH, and hypertension was significantly higher than that of normotension. Finally, the magnitude of WCE or RWCE in systolic showed a significant correlation with systolic BP variability. In conclusion, the magnitude of WCE or RWCE correlates with 24-h PP and systolic BP variability, which may suggest increased arterial stiffness in WCH and MH.

Aging and hypertension

Aging is known to be a dominant risk factor in the progression of hypertension. Thus, accompanied by an increasing mean age of the population in developed countries, prevention and management of hypertension in the elderly is a task of pressing urgency. Age-associated blood pressure elevation is a result of the aging process in organ systems, which play a key role in the regulation of blood pressure. In addition, advanced aging of the cardiovascular system contributes to the presence of a varied phenotype in elderly hypertension, such as nocturnal hypertension and morning hypertension. Therefore, in order to detect and treat age-associated hypertension appropriately, it is important to assess ambulatory blood pressure monitoring throughout the 24-h period.

Uncontrolled isolated office hypertension is associated with subclinical markers of cardiovascular disease in hypertensive type 2 diabetic patients

Isolated office hypertension (IOH) has been associated with structural cardiac abnormalities; however, its relation to worse cardiovascular prognosis remains uncertain. Less is known regarding the consequences of uncontrolled IOH in treated hypertensives. The aim was to investigate whether uncontrolled IOH was independently associated with two subclinical markers of cardiovascular disease, aortic stiffness and left ventricular hypertrophy (LVH). Clinical laboratory and 24-h ambulatory blood pressure (BP) data were obtained in 523 hypertensive patients with type 2 diabetes. Controlled office-ambulatory hypertension was defined by office blood pressure <140/90 mm Hg and 24-h BP <130/80 mm Hg, whereas uncontrolled IOH by office blood pressure> or =140/90 mm Hg and 24-h BP <130/80 mm Hg. Arterial stiffness was assessed by carotid-femoral pulse wave velocity (PWV) and left ventricular mass index (LVMI) by echocardiography. Statistics included multivariate linear and logistic regressions. According to BP patterns, 152 patients (29.1%) had controlled office-ambulatory hypertension, and 172 (32.9%) had uncontrolled IOH. Patients with uncontrolled IOH had greater LVMI (62.0+/-21.9 vs. 52.9+/-17.0 g m(-2.7), P<0.001) and PWV (11.5+/-2.4 vs. 10.2+/-2.1 m s(-1), P<0.001) than those with controlled hypertension. On linear model, after adjustment for several potential confounders, patients with uncontrolled IOH persisted with higher PWV (P=0.003) and LVMI (P=0.015). On logistic regression, the presence of uncontrolled IOH was independently associated with 2.7-fold (95% CI: 1.3-5.5) and 2.1-fold (95% CI: 1.1-4.0) higher risks of having increased aortic stiffness and LVH, respectively. In conclusion, uncontrolled IOH is associated with increased aortic stiffness and LVH in hypertensive type 2 diabetic patients. This may be a link to augmented cardiovascular risk.

High prevalence of cardiovascular risk factors in children and adolescents with type 1 diabetes: a population-based study

AIMS/HYPOTHESIS

The risk of dying of cardiovascular disease (CVD) before the age of 40 years is increased nearly 20-fold in patients with type 1 diabetes compared with non-diabetic persons. The aim of this study was to evaluate the prevalence of CVD risk factors in a population-based study of children and adolescents with type 1 diabetes.

METHODS

CVD risk factors were examined according to the American Diabetes Association criteria in 2005. Of 26 paediatric clinics in Norway, 25 participated with 1,658 patients, 85% of those eligible. Mean age was 13.1 years and mean diabetes duration 5.7 years.

RESULTS

HbA(1c) was above the target level in 71.4%. A positive family history of early CVD and/or diabetes was found in 33% of participants. LDL-cholesterol was >2.6 mmol/l in 34.5% and HDL-cholesterol was <1.1 mmol/l in 6.9% of participants. Blood pressure was above the 90th percentile by age, sex and height in 7% and above the 95th percentile in 4% of participants. Four per cent of participants were obese, 3% of those >or=12 years of age reported smoking and 1% of all participants had persistent microalbuminuria. Only 0.2% of the patients were receiving statin and 0.3% anti-hypertensive treatments. Dietary habits and physical activity level were evaluated in some patients. Almost all had higher intake of dietary fat and lower intake of fibre than recommended. A large part was less active and watched more TV than recommended.

CONCLUSIONS/INTERPRETATION

Of the participants, 86% had at least one, 45% at least two and 15% at least three CVD risk factors. Few patients were treated with statins and anti-hypertensive drugs.