Systolic and diastolic hypertension impair endothelial vasodilatory function in different types of vessels in the elderly: the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study

Influence of early life risk factors and lifestyle on systemic vascular resistance in later adulthood: the cardiovascular risk in young Finns study

PURPOSE

There are limited data available concerning the effects of lifetime risk factors and lifestyle on systemic hemodynamics, especially on systemic vascular resistance. The purpose of the study was to evaluate how lifetime cardiovascular risk factors (body mass index (BMI), high-density lipoprotein, low-density lipoprotein, triglycerides, systolic blood pressure, blood glucose) and lifestyle factors (vegetable consumption, fruit consumption, smoking and physical activity) predict systemic vascular resistance index (SVRI) and cardiac index (CI) assessed in adulthood.

MATERIALS AND METHODS

Our study cohort comprised 1635 subjects of the Cardiovascular Risk in Young Finns Study followed up for 27 years since baseline (1980; aged 3-18 years, females 54.3%) who had risk factor and lifestyle data available since childhood. Systemic hemodynamics were measured in 2007 (aged 30-45 years) by whole-body impedance cardiography.

RESULTS

In the multivariable regression analysis, independent predictors of the adulthood SVRI were childhood BMI, blood glucose, vegetable consumption, smoking, and physical activity (p ≤ .046 for all). Vegetable consumption, smoking, and physical activity remained significant when adjusted for corresponding adult data (p ≤ .036 for all). For the CI, independent predictors in childhood were BMI, systolic blood pressure, vegetable consumption, and physical activity (p ≤ .044 for all), and the findings remained significant after adjusting for corresponding adult data (p ≤ .046 for all). The number of childhood and adulthood risk factors and unfavourable lifestyle factors was directly associated with the SVRI (p < .001) in adulthood. A reduction in the number of risk factors and unfavourable lifestyle factors or a favourable change in BMI status from childhood to adulthood was associated with a lower SVRI in adulthood (p < .001).

CONCLUSION

Childhood BMI, blood glucose, vegetable consumption, smoking and physical activity independently predict systemic vascular resistance in adulthood. A favourable change in the number of risk factors or BMI from childhood to adulthood was associated with lower vascular resistance in adulthood.

Systemic vascular resistance predicts the development of hypertension: the cardiovascular risk in young Finns study

PURPOSE

To study whether systemic hemodynamics, especially systemic vascular resistance, predicts the development of hypertension and improves the risk prediction of incident hypertension beyond common risk factors in the risk models in young adults.

MATERIALS AND METHODS

Typical risk factors for hypertension in the risk prediction models (systolic and diastolic blood pressure, parental history of hypertension, age, sex, body-mass index, smoking), laboratory values (high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, glucose, insulin, C-reactive protein), heart rate (HR), stroke index (SI), and systemic vascular resistance index (SVRI) calculated by whole-body impedance cardiography were evaluated in 2007 and blood pressure in 2011 in 1293 Finnish adults (aged 30-45 years; females 56%; n = 1058 normotensive in 2007).

RESULTS

Of hemodynamic variables, SVRI and HR evaluated in 2007 were independently associated with systolic blood pressure (p < 0.001 and p = 0.047, respectively) and SVRI with diastolic blood pressure measured in 2011 (p = 0.014), and SVRI and HR were independent predictors of incident hypertension (p < 0.001 and p = 0.024, respectively). SVRI was the most significant predictor of incident hypertension independently of other risk factors (odds ratio 2.73 per 1 standard deviation increase, 95% confidence interval 1.93-3.94, p < 0.001). The extended prediction model (including SVRI) improved the incident hypertension risk prediction beyond other risk factors, with an area under the receiver operating characteristic curve of 0.846 versus 0.817 (p = 0.042) and a continuous net reclassification improvement of 0.734 (p < 0.001).

CONCLUSIONS

These findings suggest that systemic vascular resistance index predicts the incidence of hypertension in young adults and that the evaluation of systemic hemodynamics could provide an additional tool for hypertension risk prediction.

Muscle microcirculation alterations and relation to dipping status in newly diagnosed untreated patients with arterial hypertension-A pilot study

OBJECTIVE

The importance of abnormalities observed in the microcirculation of patients with arterial hypertension (AH) is being increasingly recognized. The authors aimed to evaluate skeletal muscle microcirculation in untreated, newly diagnosed hypertensive patients with NIRS, a noninvasive method that evaluates microcirculation.

METHODS

We evaluated 34 subjects, 17 patients with AH (13 males, 49±13 years, BMI: 26±2 kg/m2 ) and 17 healthy controls (12 males, 49±15 years, BMI: 25±3 kg/m2 ). The thenar muscle StO2 (%) was measured by NIRS before, during and after 3-minutes vascular occlusion to calculate OCR (%/min), EF (%/min), and RHT (minute). The dipping status of hypertensive patients was assessed.

RESULTS

The RHT differed between AH patients and healthy subjects (2.6±0.3 vs 2.1±0.3 minutes, P<.001). Dippers had higher EF than nondippers (939±280 vs 710±164%/min, P=.05).

CONCLUSIONS

The study suggests an impaired muscle microcirculation in newly diagnosed, untreated AH patients.

Flow-mediated vasodilation over five years in the general elderly population and its relation to cardiovascular risk factors

BACKGROUND

Flow-mediated vasodilation (FMD) has previously been shown to be related to cardiovascular risk factors in cross-sectional studies. The present study aims to investigate how FMD changes over time, and determine whether this change is paralleled by changes in cardiovascular risk factors.

METHODS

Of the participants in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, 750 individuals had measurements made of FMD in the brachial artery both at the ages of 70 and 75 years. In addition, the change over the 5 years in carotid artery intima-media thickness (IMT) was monitored, as well as traditional cardiovascular risk factors.

RESULTS

While no significant change in FMD occurred during the 5-year period (+0.1%, p = 0.53), large changes could be seen at the individual level. The Framingham risk score (excluding the age-variable) increased during the follow-up period (+0.54, p < 0.001). This change was inversely related to the individual change in FMD (beta -0.15, 95% CI -0.29 to -0.0059, p = 0.041). Of the eight individual CV risk factors tested, the change in FMD was only related to the change in LDL-cholesterol (inversely, p = 0.0028). The change in FMD was not related to the change in IMT seen over the 5-year period (p = 0.41).

CONCLUSION

While no change was seen in the mean FMD over a five-year period in elderly subjects attending both examinations despite ageing and a change in several risk factors, the individual change was mainly related to the change in LDL-cholesterol, further emphasizing the important role of lipids to determine vasoreactivity.

Endothelial function and carotid intima-media thickness in giant-cell arteritis

BACKGROUND

Vascular endothelial dysfunction and intima-media thickness are characteristic aspects of several vasculitides. We investigated retrospectively the impact of steroid treatment on endothelial dysfunction and intima-media thickness in giant-cell arteritis.

METHODS

Forty-one patients with giant-cell arteritis (28 female and 13 male) underwent flow-mediated dilatation, a marker of endothelial function, and carotid intima-media thickness within 24 h after diagnosis and 6 months thereafter. Both parameters were investigated in 41 patients of an age- and gender-matched control group.

RESULTS

Brachial flow-mediated dilatation response at baseline was 3.4% (0.2, 8.0) and 1.7% (0.2, 4.8) in giant-cell arteritis patients and control group, respectively. After 6 months treatment, flow-mediated dilatation response was 2.8% (0.4, 4.8) in patients with giant-cell arteritis (P = 0.066) and 1.4% (0.1, 5.5) in the control group (P = 0.741). In contrast, mean carotid intima-media thickness of giant-cell arteritis patients improved significantly between baseline [1.0 mm (0.79, 1.2)] and 6-month follow-up [0.82 mm (0.7, 1.04), P < 0.001]. Subjects with additional symptoms of polymyalgia rheumatica had a notable enlargement of carotid intima-media thickness [1.23 mm (1.14, 2.09)] compared to giant-cell arteritis patients without polymyalgia rheumatica at baseline [0.91 mm (0.76, 1.04), P = 0.001] and 6-month follow-up [1.16 mm (0.80, 1.26) vs. 0.77 mm (0.68, 0.88), P = 0.009].

CONCLUSION

Steroid therapy has no influence on endothelial function but does significantly improve carotid intima-media thickness in giant-cell arteritis. This divergence of endothelial function and intima-media thickness reflects the specifity of giant-cell arteritis for cerebrovascular arteries thereby sparing the brachial arteries.

Is isolated systolic hypertension worse than combined systolic/diastolic hypertension?

New developments in cardiovascular translational sciences have significantly advanced our understanding of the endovascular biology of blood pressure. Reductions in vascular elasticity and vessel compliance of conduit arteries are key components of both ISH and SDH. Vascular changes from the matrix metalloproteinase family of enzymes are involved in arterial wall remodeling and vascular stiffness. This new translational information helps further our understanding of both ISH and SDH.

Coronary microvascular function in patients with isolated systolic and combined systolic/diastolic hypertension

Isolated systolic hypertension (ISH) is a common condition in the elderly that is associated with endothelial dysfunction. Concerning the effect of type of hypertension on coronary microvascular function, coronary flow reserve (CFR) in patients with ISH was evaluated and the results were compared with patients with combined systolic/diastolic hypertension (SDH). Seventy-six elderly patients (older than 60 years) who were free of coronary artery disease and diabetes mellitus were enrolled in the study (38 with ISH and 38 with combined SDH). Using transthoracic Doppler echocardiography, CFR was calculated as the ratio of hyperemic to baseline diastolic peak flow velocities. A CFR value of >2 was accepted as normal. The mean age was 68.6±6.3 years and the groups had similar features with regard to demographic and clinical characteristics. Patients with ISH had significantly lower CFR values compared with those with combined SDH (2.22±0.51 vs 2.49±0.56, respectively; P=.03). On multivariate regression analysis, ISH (β=-0.40, P=.004) and dyslipidemia (β=-0.29, P=.04) were the independent predictors of CFR. These findings indicate that CFR, an indicator of coronary microvascular/endothelial function, is impaired more profoundly in patients with ISH than in patients with combined SDH.

Is Peri-Operative Isolated Systolic Hypertension (ISH) a Cardiac Risk Factor?

We are presenting a review of Isolated Systolic Hypertension (ISH) as a cardiovascular risk factor with emphasis on the perioperative period.

Isolated systolic hypertension is associated with aging and is the most frequent subtype (65%) among patients with uncontrolled hypertension. ISH is strongly associated with increased risks of cardiac and cerebrovascular events exceeding those in comparably aged individuals with diastolic hypertension. Patients with ISH show an increase in left ventricular (LV) mass and an increase in the prevalence of left ventricular hypertrophy (LVH). These LV changes increase cardiovascular events and frequently lead to diastolic dysfunction (DD). Treatment to reduce elevated systolic blood pressure has been shown to reduce the risk of cardiovascular events.

In the perioperative setting, essential hypertension has not been found to be a significant risk factor for cardiac complications. Most of the studies were based on the definition of essential hypertension and underpowered in sample size. The significance of perioperative ISH, however, is not well studied, partly due to its recognition only fairly recently as a cardiovascular risk factor in the non-surgical setting, and partly due to the evolving definition of ISH.

Perioperative cardiac complications remain a significant problem to the healthcare system and to the patient. Although the incidence of perioperative cardiac complications is prominent in high-risk patients as defined by the Revised Cardiac Risk Index (RCRI), the bulk of the cardiac complications actually occur in low-risk group. Currently, little understanding exists on the occurrence of perioperative cardiac complications in low- risk patients. A factor such as ISH, with its known pathophysiological changes, is a potential perioperative risk factor.

We believe ISH is an under-recognized perioperative risk factor and deserves further studying. Our research group has recently been funded by the Heart Stroke Foundation (HSF) to examine ISH as a perioperative risk factor (PROMISE Study).

Endothelial function in resistance and conduit arteries and 5-year risk of cardiovascular disease

BACKGROUND

Impaired endothelial function has been implicated as a cause of cardiovascular disease. Little is known of the relations of measures of endothelial function in resistance and conduit arteries to incident cardiovascular disease in the general population, and available techniques have not been compared.

METHODS AND RESULTS

In 1016 participants (70 years of age) of the population-based Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) study (52% women), we measured endothelium-dependent vasodilation using the invasive forearm technique with acetylcholine given in the brachial artery, the brachial artery ultrasound technique with measurement of flow-mediated dilatation, and the pulse-wave analysis-based method with β-2-agonist terbutaline provocation. During 5 years of follow-up, 101 participants experienced a composite end point of myocardial infarction, stroke, or death, excluding the 85 persons with a history of myocardial infarction or stroke at baseline. In logistic regression models adjusted for several established and novel cardiovascular disease risk factors and medications, endothelium-dependent vasodilation by the invasive forearm technique with acetylcholine was associated with risk of the end point (odds ratio, 0.72 per SD; 95% confidence interval, 0.56 to 0.93; P=0.01). Endothelial function by the other 2 methods was not related to risk of the end point. Addition of endothelium-dependent vasodilation to the Framingham risk score improved discrimination of risk of the end point.

CONCLUSIONS

Endothelium-dependent vasodilation in resistance arteries, but not in the brachial conduit artery (flow-mediated dilatation), was associated with 5-year risk of a composite end point of death, myocardial infarction, or stroke independently of major cardiovascular disease risk factors. This vascular measurement improved risk discrimination when added to an established risk score in an elderly population.

Dyslipidemia and the risk of incident hypertension in a population of community-dwelling Brazilian elderly: the Bambuí cohort study of aging

This study aimed to examine the prognostic value of lipid parameters for incident hypertension in elderly living in a community. The study included 306 (81% from total) persons aged > 60 years who were free of hypertension and of cardiovascular diseases at the baseline survey of the Bambuí Cohort Study of Aging. The cumulative incidence of hypertension over three years was 37.3%. The relative risk (RR) of incident hypertension decreased 0.92 for each unit of HDL-cholesterol (95%CI: 0.86-0.99) independent of several potential confounding factors. Individuals with HDL-cholesterol in the top tercile (> 55mg/dL) had a risk of hypertension halve that those in the bottom tercile (RR = 0.54; 95%CI: 0.33-0.90). Other lipid parameters had no significant effect on the outcome. High HDL-cholesterol showed an independent protective effect on subsequent development of hypertension in the elderly.

Coffee consumption and CYP1A2 genotype in relation to bone mineral density of the proximal femur in elderly men and women: a cohort study

Background

Drinking coffee has been linked to reduced calcium conservation, but it is less clear whether it leads to sustained bone mineral loss and if individual predisposition for caffeine metabolism might be important in this context. Therefore, the relation between consumption of coffee and bone mineral density (BMD) at the proximal femur in men and women was studied, taking into account, for the first time, genotypes for cytochrome P450 1A2 (CYP1A2) associated with metabolism of caffeine.

Methods

Dietary intakes of 359 men and 358 women (aged 72 years), participants of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS), were assessed by a 7-day food diary. Two years later, BMD for total proximal femur, femoral neck and trochanteric regions of the proximal femur were measured by Dual-energy X-ray absorptiometry (DXA). Genotypes of CYP1A2 were determined. Adjusted means of BMD for each category of coffee consumption were calculated.

Results

Men consuming 4 cups of coffee or more per day had 4% lower BMD at the proximal femur (p = 0.04) compared with low or non-consumers of coffee. This difference was not observed in women. In high consumers of coffee, those with rapid metabolism of caffeine (C/C genotype) had lower BMD at the femoral neck (p = 0.01) and at the trochanter (p = 0.03) than slow metabolizers (T/T and C/T genotypes). Calcium intake did not modify the relation between coffee and BMD.

Conclusion

High consumption of coffee seems to contribute to a reduction in BMD of the proximal femur in elderly men, but not in women. BMD was lower in high consumers of coffee with rapid metabolism of caffeine, suggesting that rapid metabolizers of caffeine may constitute a risk group for bone loss induced by coffee.

Serum adiponectin in elderly men does not correlate with fracture risk

CONTEXT

Recent evidence suggests that adiponectin may play a role in bone metabolism, but studies of the correlation between serum adiponectin and bone mineral density (BMD) have given conflicting results, and the impact on fracture risk is unknown.

OBJECTIVE

Our objective was to investigate the association between serum adiponectin levels and BMD and fracture risk. DESIGN, SETTING, PARTICIPANTS, MAIN OUTCOME MEASURES: We used regression analyses to estimate the relationship between adiponectin and BMD in the Prospective Investigation of the Vasculature in Uppsala Seniors cohort of 441 men and 457 women aged 70 yr. The association was thereafter analyzed in the Uppsala Longitudinal Study of Adult Men (ULSAM), in which adiponectin was analyzed at age 70 yr and BMD at 82 yr in 507 men. Fractures in the ULSAM were documented in 314 men during 15 yr follow-up. Cox regression analysis was used to determine the risk of fracture according to serum adiponectin levels.

RESULTS

In multivariable analysis a negative association between adiponectin and BMD was found in both cohorts. When individuals in the highest quintile of adiponectin were compared with those in the lowest quintile, adjusted BMD was 9.7% lower at the lumbar spine, 7.1% lower at the proximal femur, and 5.2% lower for total body in the Prospective Investigation of the Vasculature in Uppsala Seniors (P < 0.001 for all three), and 8.1, 5.1, and 4.1% (P < 0.003 for all three), respectively, in the ULSAM. However, the hazard ratio for fracture per 1 sd of serum adiponectin was 0.99 (95% confidence interval 0.89-1.11).

CONCLUSION

Although adiponectin was a negative determinant of BMD in two independent cohorts, it was not associated with fracture risk in men.

Relationship of fibrinogen with arterial stiffness and wave reflections

INTRODUCTION

Increased levels of fibrinogen have been related to target organ damage and cardiovascular outcomes. Arterial elastic properties are important determinants of cardiovascular performance and predictors of the corresponding risk. This study investigated whether the fibrinogen level is associated with arterial stiffness and wave reflections.

METHODS

We studied 229 consecutive, non-diabetic patients with uncomplicated, never-treated essential hypertension (mean age 51 years, 149 men) and an age-matched control group of 159 normotensive individuals (mean age 50 years, 83 men). Carotid-femoral and carotid-radial pulse wave velocity (PWVc-f and PWVc-r) were measured as indices of elastic-type, aortic stiffness and muscular type, medium-sized arterial stiffness, respectively. The heart rate-corrected augmentation index (AIx75) was estimated as a composite marker of wave reflections and arterial stiffness. Plasma fibrinogen was measured using immunonephelometry.

RESULTS

The fibrinogen level and arterial function indices (PWVc-f, PWVc-r, AIx75) were significantly higher in hypertensive patients than controls. In the whole population, fibrinogen level correlated with PWVc-f and AIx75 in univariable analysis, but not with PWVc-r. In multivariable analysis, an independent association was established between fibrinogen level and PWVc-f after adjusting for age, sex, mean pressure, heart rate, height, body mass index, smoking status, and total cholesterol. In contrast, no significant relationship was observed between fibrinogen and AIx75 after adjusting for confounders.

CONCLUSION

The plasma fibrinogen level is independently associated with aortic stiffening. This finding underlines the important role of fibrinogen as a marker of arterial damage, and implies a possible contribution of this compound to the pathophysiology of cardiovascular disease.

Isolated systolic hypertension is characterized by increased aortic stiffness and endothelial dysfunction

Isolated systolic hypertension is associated with increased cardiovascular risk. It is thought to result from large artery stiffening, which is determined by structural components within the vasculature but also by functional factors including NO and endothelin-1. We hypothesized that endothelial dysfunction would account for increased arterial stiffness in patients with isolated systolic hypertension. The aim of this study was to investigate the relationship between endothelial function and arterial stiffness in these patients along with control subjects. We studied 113 subjects: 35 patients with isolated systolic hypertension (mean age+/-SD: 68+/-6 years), 30 age-matched control subjects (65+/-5 years), and 48 young control subjects (37+/-9 years). Aortic pulse wave velocity (PWV) was derived by sequential carotid/femoral waveform recordings. Conduit artery endothelial function was determined by flow-mediated dilatation. Aortic PWV was higher (9.65+/-2.56 m/s versus 8.26+/-0.85 m/s; P=0.009), and flow-mediated dilatation was lower (2.67+/-1.64% versus 4.79+/-3.1%; P=0.03) in patients with isolated systolic hypertension compared with age-matched control subjects. Similarly, aortic PWV was also higher, and flow-mediated dilatation lower, in older versus young control subjects (8.26+/-0.85 m/s versus 7.09+/-1.01 m/s and 4.79+/-3.1% versus 6.94+/-2.7%; P=0.004 for both). Overall, aortic PWV correlated inversely with flow-mediated dilatation (r=-0.3; P=0.001), which remained significant after adjustment for confounding factors (P=0.01). Patients with isolated systolic hypertension have higher aortic PWV and decreased endothelial function compared with age-matched control subjects. Our results suggest that endothelial function contributes significantly to increased arterial stiffness in patients with isolated systolic hypertension and with age.

Are we misunderstanding beta-blockers

In myocardial ischaemia and heart failure, beta-blockers with intrinsic sympathomimetic activity (ISA) e.g. pindolol, xamoterol, bucindolol, nebivolol, have performed poorly in reducing morbidity and mortality. In both indications beta-1 blockade is the vital active ingredient. Beta-1 blockade (bisoprolol) is now an alternative first-line choice to Ace-inhibition in the treatment of heart failure. The therapeutic role of beta-blockers in hypertension is less well understood, particularly since the new recommendations in the UK from the NICE committee stating that: 1. beta-blockers are no longer preferred as a routine initial therapy, 2. the combination with diuretics is discouraged due to the risk of induced diabetes, and 3. in younger patients first-choice initial therapy should be an ACE-inhibitor. Recent data from the Framingham Heart Study and other epidemiological studies have indicated that the development of diastolic hypertension in younger subjects is closely linked to weight-increase and an increase in peripheral resistance; such subjects have a high adrenergic drive and cardiac output. In contrast, elderly systolic hypertension mostly arises de novo via poor vascular compliance. Thus in younger, probably overweight, hypertensives (including diabetics) first-line beta-blockade has performed well in preventing myocardial infarction (a fact hidden by meta-analyses that do not take age into account). Conversely, in elderly hypertensives first-line beta-blockade (atenolol) has performed poorly in reducing cardiovascular risk (due to partial beta-2 blockade atenolol evokes metabolic disturbance and does not improve vascular compliance, or effectively lower central aortic pressure or reverse left ventricular hypertrophy). Thus beta-blockers like atenolol are ill-equipped for first-line therapy in elderly hypertension. Some beta-blockers, e.g. bisoprolol (up to 10 mg/day is highly beta-1 selective) and nebivolol (beta-2/3 intrinsic sympathomimetic activity), do improve vascular compliance and cause no metabolic disturbance. Beta-blockers as second-line to low-dose diuretics (which, by improving vascular compliance and increasing sympathetic nerve activity, create an optimal environment for beta-blockade) in elderly hypertension (including diabetics) have performed well in reducing cardiovascular events (this combination has the added bonus of reducing the risk of bone fracture by about 30%). Meta-analyses which include studies where it is unclear whether a diuretic or beta-blocker was a first-line therapy will dilute the benefit stemming from first-line diuretic/second-line beta-blockade. Hypertensives (of all ages) with ischaemia are well suited to beta-blockade.