Isolated elevation of diastolic blood pressure. Real or artifactual?

Cardiorespiratory Fitness and Carotid Intima-Media Thickness in Physically Active Young Adults: CHIEF Atherosclerosis Study

Background: The relationship of cardiorespiratory fitness (CRF) with subclinical atherosclerosis affected by the body adiposity has been observed in children, whereas this relationship remains unclear in young adults. Methods and Results: A total of 1520 military recruits, aged 18−40 years, were included in Taiwan in 2018−2020. All subjects underwent detailed physical and blood laboratory examinations. CRF was evaluated by time for a 3000 m run, and subclinical atherosclerosis was evaluated by intima−media thickness of the bulb of the left common carotid artery (cIMT) utilizing high-resolution ultrasonography. Multivariable linear regression analysis with adjustments for age, sex, cigarette smoking, alcohol intake, systolic and diastolic blood pressure, high- and low-density lipoprotein cholesterols, fasting glucose, waist circumference, serum uric acid and serum triglycerides were utilized to determine the correlation between CRF and cIMT. CRF was independently correlated with cIMT (standardized β: 0.11, p < 0.001). Of the cardiometabolic risk markers, serum triglycerides were the only independent risk marker of cIMT (standardized β: 0.063, p = 0.03). In addition, the association of CRF with cIMT did not differ between those with a body mass index (BMI) ≥ 25 kg/m2 and those with BMI < 25 kg/m2 (standardized β: 0.103 and 0.117; p = 0.01 and 0.005, respectively). Conclusions: In physically active young men and women, there was an inverse association of cIMT with CRF, which was observed in both overweight/mild obesity and normal-weight individuals, highlighting the importance of endurance capacity on reducing risk of early atherosclerosis and implying that the moderation effect of body adiposity might not be present in this population.

Elevated On-Treatment Diastolic Blood Pressure and Cardiovascular Outcomes in the Presence of Achieved Systolic Blood Pressure Targets

BACKGROUND AND OBJECTIVES

This study aimed to investigate the association between cardiovascular events and 2 different levels of elevated on-treatment diastolic blood pressures (DBP) in the presence of achieved systolic blood pressure targets (SBP).

METHODS

A nation-wide population-based cohort study comprised 237,592 patients with hypertension treated. The primary endpoint was a composite of cardiovascular death, myocardial infarction, and stroke. Elevated DBP was defined according to the Seventh Report of Joint National Committee (JNC7; SBP <140 mmHg, DBP ≥90 mmHg) or to the 2017 American College of Cardiology/American Heart Association (ACC/AHA) definitions (SBP <130 mmHg, DBP ≥80 mmHg).

RESULTS

During a median follow-up of 9 years, elevated on-treatment DBP by the JNC7 definition was associated with an increased risk of the occurrence of primary endpoint compared with achieved both SBP and DBP (adjusted hazard ratio [aHR], 1.14; 95% confidence interval [CI], 1.05-1.24) but not in those by the 2017 ACC/AHA definition. Elevated on-treatment DBP by the JNC7 definition was associated with a higher risk of cardiovascular mortality (aHR, 1.42; 95% CI, 1.18-1.70) and stroke (aHR, 1.19; 95% CI, 1.08-1.30). Elevated on-treatment DBP by the 2017 ACC/AHA definition was only associated with stroke (aHR, 1.10; 95% CI, 1.04-1.16). Similar results were seen in the propensity-score-matched cohort.

CONCLUSION

Elevated on-treatment DBP by the JNC7 definition was associated a high risk of major cardiovascular events, while elevated DBP by the 2017 ACC/AHA definition was only associated with a higher risk of stroke. The result of study can provide evidence of DBP targets in subjects who achieved SBP targets.

Isolated Diastolic Hypertension in the IDACO Study: An Age-Stratified Analysis Using 24-Hour Ambulatory Blood Pressure Measurements

[Figure: see text].

Clinical and central hemodynamic characteristics of early adulthood isolated diastolic hypertension: a comparison with isolated systolic hypertension

OBJECTIVES

Knowledge on early adulthood isolated diastolic hypertension (IDH) is limited. We compared the clinical and central hemodynamic characteristics of early adulthood IDH, isolated systolic hypertension (ISH) and normotension.

METHODS

A total of 509 untreated young adults (18-35 years) who underwent ambulatory blood pressure monitoring (ABPM; ABPM cohort), 148 who underwent both ABPM and applanation tonometry (ABPM-tonometry cohort) and 26 newly recruited normotensives were analyzed. Their pulse wave images were analyzed after categorizing them into type A vs. B vs. C.

RESULTS

In the ABPM cohort (men, 86.6%), systolic-diastolic hypertension was the most common subtype (68.0%), while IDH was the rarest (5.1%). The subtype composition showed age-dependency; the proportion of IDH and systolic-diastolic hypertension increased across the age tertiles, while that of ISH declined. Patients with IDH were significantly older and shorter than those with ISH. Despite having a significantly lower 24-h average systolic blood pressure (SBP), patients with IDH exhibited discordantly high central systolic blood pressures at levels comparable to those of patients with ISH. Pulse pressure amplification was the lowest in patients with IDH and highest in those with ISH (P < 0.001), accounting for the discordance. Augmentation index differed significantly between them (P < 0.016). The waveform composition differed across the subtypes (type A vs. B/C: IDH = 61.5 vs. 38.5%; ISH = 3.0 vs. 97.0%; normotension = 30.8 vs. 69.2%, P < 0.001); the averaged waveform plots demonstrated a clear morphological disparity between IDH (type A) and ISH (type B/C).

CONCLUSIONS

Early adulthood IDH is a unique entity clearly distinguishable from ISH in terms of clinical and central hemodynamic characteristics.

A cohort study and meta-analysis of isolated diastolic hypertension: searching for a threshold to guide treatment

AIMS

Whether isolated diastolic hypertension (IDH), as defined by the 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guideline, is associated with cardiovascular disease (CVD) has been disputed. We aimed to further study the associations of IDH with (i) subclinical CVD in the form of coronary artery calcium (CAC), (ii) incident systolic hypertension, and (iii) CVD events.

METHODS AND RESULTS

We used multivariable-adjusted logistic and Cox regression to test whether IDH by 2017 ACC/AHA criteria (i.e. systolic blood pressure <130 mmHg and diastolic blood pressure ≥80 mmHg) was associated with the above outcomes in the Multi-Ethnic Study of Atherosclerosis (MESA). In a random-effects meta-analysis of the association between IDH and CVD events, we combined the MESA results with those from seven other previously published cohort studies. Among the 5104 MESA participants studied, 7.5% had IDH by the 2017 ACC/AHA criteria. There was no association between IDH and CAC [e.g. adjusted prevalence odds ratio for CAC >0 of 0.88 (95% CI 0.66, 1.17)]. Similarly, while IDH was associated with incident systolic hypertension, there was no statistically significant associations with incident CVD [hazard ratio 1.19 (95% CI 0.77, 1.84)] or death [hazard ratio 0.94 (95% CI 0.65, 1.36)] over 13 years in MESA. In a stratified meta-analysis of eight cohort studies (10 037 843 participants), the 2017 IDH definition was also not consistently associated with CVD and the relative magnitude of any potential association was noted to be numerically small [e.g. depending on inclusion criteria applied in the stratification, the adjusted hazard ratios ranged from 1.04 (95% CI 0.98, 1.10) to 1.09 (95% 1.03, 1.15)].

CONCLUSION

The lack of consistent excess in CAC or CVD suggests that emphasis on healthy lifestyle rather than drug therapy is sufficient among the millions of middle-aged or older adults who now meet the 2017 ACC/AHA criteria for IDH, though they require follow-up for incident systolic hypertension. These findings may not extrapolate to adults younger than 40 years, motivating further study in this age group.

The effect of remote ischaemic conditioning on blood pressure response: A systematic review and meta-analysis

BACKGROUND

Previous work has evaluated the effect of remote ischaemic conditioning (RIC) in a number of clinical conditions (e.g. cardiac surgery and acute kidney injury), but only one analysis has examined blood pressure (BP) changes. While individual studies have reported the effects of acute bouts and repeated RIC exposure on resting BP, efficacy is equivocal. We conducted a systematic review and meta-analysis to evaluate the effects of acute and repeat RIC on BP.

METHODS

A systematic search was performed using PubMed, Web of Science, EMBASE, and Cochrane Library of Controlled Trials up until October 31, 2020. Additionally, manual searches of reference lists were performed. Studies that compared BP responses after exposing participants to either an acute bout or repeated cycles of RIC with a minimum one-week intervention period were considered.

RESULTS

Eighteen studies were included in this systematic review, ten examined acute effects while eight investigated repeat effects of RIC. Mean differences (MD) for outcome measures from acute RIC studies were: systolic BP 0.18 mmHg (95%CI -0.95, 1.31; p = 0.76), diastolic BP -0.43 mmHg (95%CI -2.36, 1.50; p = 0.66), MAP -1.73 mmHg (95%CI -3.11, -0.34; p = 0.01) and HR -1.15 bpm (95%CI -2.92, 0.62; p = 0.20). Only MAP was significantly reduced. Repeat RIC exposure showed non-significant change in systolic BP -3.23 mmHg (95%CI -6.57, 0.11; p = 0.06) and HR -0.16 bpm (95%CI -7.08, 6.77; p = 0.96) while diastolic BP -2.94 mmHg (95%CI -4.08, -1.79; p < 0.00001) and MAP -3.21 mmHg (95%CI -4.82, -1.61; p < 0.0001) were significantly reduced.

CONCLUSIONS

Our data suggests repeated, but not acute, RIC produced clinically meaningful reductions in diastolic BP and MAP.

Isolated diastolic hypertension as defined by the 2017 American College of Cardiology/American Heart Association blood pressure guideline and incident cardiovascular events in Chinese

OBJECTIVE

The new arterial hypertension guidelines by the 2017 American College of Cardiology (ACC)/American Heart Association (AHA) changed the definition of isolated diastolic hypertension (IDH). We assessed and compared in a Chinese population the IDH prevalence, newly defined by the 2017 ACC/AHA guidelines versus the former definition by the Joint National Committee 7 (JNC7) criteria, and examined longitudinal associations of IDH with cardiovascular disease (CVD) outcomes.

METHODS

The prospective community-based Kailuan Study included participants aged 18-98 years who underwent a detailed medical examination at baseline in 2006/2007 and who were biennially re-examined till 2017. History of antihypertensive medication at baseline was an exclusion criterion.

RESULTS

The study population consisted of 87 346 individuals (mean age: 50.9 years; range: 18-98 years). Prevalence of IDH was 7.79% [95% confidence interval (CI): 7.62, 7.97] by JNC7 guidelines and 24.72% (95% CI: 24.43, 25.01) by 2017 ACC/AHA criteria [difference: 19.93% (95% CI: 16.81, 17.04)]. Applying the 2017 ACC/AHA guidelines, the prevalence of IDH-recommended antihypertensive therapy was 7.73% (95% CI: 7.55, 7.90). In multivariable analysis, IDH by JNC7 criteria was significantly associated with incident myocardial infarction [n = 93 events; hazard ratio: 1.30 (95 CI: 1.02, 1.66)], cerebral hemorrhage [n = 73 events; hazard ratio: 1.79 (95% CI: 1.35, 2.38)], and total CVD [n = 373 events; hazard ratio: 1.15 (95% CI: 1.02, 1.30)], when compared with normotension. IDH based on 2017 ACC/AHA guidelines was associated with incident cerebral hemorrhage [n = 129 events; hazard ratio: 1.47 (95% CI: 1.12, 1.94)] and total CVD [n = 828 events; hazard ratio: 1.13 (95% CI: 1.02, 1.26)].

CONCLUSION

In this adult Chinese community, 2017 ACC/AHA-defined IDH was associated with the incidence of cerebral hemorrhage and total CVD, and as compared with JNC7-defined IDH, it was more prevalent.

Isolated Diastolic Hypertension in the UK Biobank: Comparison of ACC/AHA and ESC/NICE Guideline Definitions

The 2017 American College of Cardiology/American Heart Association guideline defines hypertension as a blood pressure ≥130/80 mm Hg, whereas the 2018 European Society of Cardiology (ESC) and 2019 National Institute for Health and Care Excellence (NICE) guidelines use a ≥140/90 mm Hg threshold. Our objective was to study the associations between isolated diastolic hypertension (IDH), diagnosed using these 2 blood pressure thresholds, and cardiovascular disease (CVD) in a large cohort of UK adults. We analyzed data from UK Biobank, which enrolled participants between 2006 and 2010 with follow-up through March 2019. We excluded persons with systolic hypertension or baseline CVD. We defined incident CVD as a composite of nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. We used Cox regression to quantify associations between IDH and CVD, as well as the individual outcomes included in the composite outcome. We studied 151 831 participants with normal systolic blood pressure (mean age 54 years, 40% male). Overall, 24.5% had IDH by the American College of Cardiology/American Heart Association definition compared with 6% by the ESC/NICE definition. Compared with normal diastolic blood pressure, IDH by the American College of Cardiology/American Heart Association definition was not significantly associated with CVD risk (hazard ratio, 1.08 [95% CI, 0.98-1.18]) whereas IDH by the ESC/NICE definition was significantly associated with a modest increase in CVD (hazard ratio, 1.15 [95% CI, 1.04-1.29]). Similar results were found by sex and among participants not taking baseline antihypertensives. Furthermore, neither IDH definition was associated with the individual outcomes of nonfatal myocardial infarction or stroke. In conclusion, the proportion of UK Biobank participants with IDH was significantly higher by the American College of Cardiology/American Heart Association definition compared with the ESC/NICE definitions; however, only the ESC/NICE definition was statistically associated with increased CVD risk.

The clinical significance of isolated diastolic hypertension

The prevalence of isolated diastolic hypertension (IDH) has been increased in hypertensive subjects with the new 2017 ACC/AHA blood pressure treatment guidelines to 6.5% from 1.3% by the JNC-7 guidelines. However, its clinical significance as a cause of adverse cardiovascular (CV) events especially in older subjects has been debated by several investigators, who have demonstrated no adverse CV effects of untreated IDH, but not by others. It is also more common in the young subjects who are at low CV risk and quite rare in the older subjects, who are at increased CV risk. Treatment of IDH in the older subjects could increase the CV complications due to a J-curve effect and, in addition, could increase the incidence of stroke from further lowering the normal systolic blood pressure (SBP). Very low SBP and DBP cannot be sustained by the cerebral blood flow autoregulation and could lead to cerebral ischemia. In order to get a better perspective of the current status of the treatment of IDH, a review of the English language literature of the available studies was conducted and 12 papers with pertinent information were retrieved. The analysis of results from these studies suggests that IDH is associated with adverse CV events in younger persons and it should be treated. In contrast, the prevalence of IDH is low in older subjects and is not associated with adverse CV events in the majority of cases. Thus, its further lowering should be avoided to prevent further decrease in normal SBP and prevent the onset of adverse CV events. However, the decision to treat IDH in older subjects should be individualized.

Cardiac vagal control mediates the relation between past depression and blood pressure several years later among young adults

Depression has been associated with high blood pressure (BP). However, the mechanisms of the relation between depression and high BP are unclear. We therefore examined whether impaired cardiac vagal control, indexed as low levels of resting respiratory sinus arrhythmia (RSA), serves as a route from depression to high BP. The sample included 125 subjects with histories of depression (probands), 123 never depressed siblings of probands (high-risk siblings), and 156 controls. Resting RSA was assessed at Time 1 (T1) along with BP when subjects were adolescents (M_age  = 16.3 years); systolic and diastolic BP (SBP and DBP) were measured again at Time 2 (T2) when subjects were young adults (M_age  = 22.3 years). Linear mixed-effects models were used to examine the group differences in resting RSA and T2 BP outcomes and to test for RSA mediation of the relation between depression (history or being at high risk) and BP. Resting RSA was lower among probands than controls but was similar among high-risk siblings and controls, while the subject groups did not differ in T2 SBP or DBP. Controlling for T1 BP, depression history indirectly affected T2 DBP (but not SBP) through resting RSA. The findings suggest that, although the direct detrimental effects of depression on BP are not yet evident in young adulthood, among those with depression histories, impaired cardiac vagal control appears to serve as a mechanism of elevated DBP.

Association of Isolated Diastolic Hypertension as Defined by the 2017 ACC/AHA Blood Pressure Guideline With Incident Cardiovascular Outcomes

IMPORTANCE

In the 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guideline, the definition of hypertension was lowered from a blood pressure (BP) of greater than or equal to 140/90 to greater than or equal to 130/80 mm Hg. The new diastolic BP threshold of 80 mm Hg was recommended based on expert opinion and changes the definition of isolated diastolic hypertension (IDH).

OBJECTIVE

To compare the prevalence of IDH in the United States, by 2017 ACC/AHA and 2003 Joint National Committee (JNC7) definitions, and to characterize cross-sectional and longitudinal associations of IDH with outcomes.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional analyses of the National Health and Nutrition Examination Survey (NHANES 2013-2016) and longitudinal analyses of the Atherosclerosis Risk in Communities (ARIC) Study (baseline 1990-1992, with follow-up through December 31, 2017). Longitudinal results were validated in 2 external cohorts: (1) the NHANES III (1988-1994) and NHANES 1999-2014 and (2) the Give Us a Clue to Cancer and Heart Disease (CLUE) II cohort (baseline 1989).

EXPOSURES

IDH, by 2017 ACC/AHA (systolic BP <130 mm Hg, diastolic BP ≥80 mm Hg) and by JNC7 (systolic BP <140 mm Hg, diastolic BP ≥90 mm Hg) definitions.

MAIN OUTCOMES AND MEASURES

Weighted estimates for prevalence of IDH in US adults and prevalence of US adults recommended BP pharmacotherapy by the 2017 ACC/AHA guideline based solely on the presence of IDH. Risk of incident atherosclerotic cardiovascular disease (ASCVD), heart failure (HF), and chronic kidney disease (CKD) in the ARIC Study.

RESULTS

The study population included 9590 adults from the NHANES (mean [SD] baseline age, 49.6 [17.6] years; 5016 women [52.3%]) and 8703 adults from the ARIC Study (mean [SD] baseline age, 56.0 [5.6] years; 4977 women [57.2%]). The estimated prevalence of IDH in the NHANES was 6.5% by the 2017 ACC/AHA definition and 1.3% by the JNC7 definition (absolute difference, 5.2% [95% CI, 4.7%-5.7%]). Among those newly classified as having IDH, an estimated 0.6% (95% CI, 0.5%-0.6%) also met the guideline threshold for antihypertensive therapy. Compared with normotensive ARIC participants, IDH by the 2017 ACC/AHA definition was not significantly associated with incident ASCVD (n = 1386 events; median follow-up, 25.2 years; hazard ratio [HR], 1.06 [95% CI, 0.89-1.26]), HF (n = 1396 events; HR, 0.91 [95% CI, 0.76-1.09]), or CKD (n = 2433 events; HR, 0.98 [95% CI, 0.65-1.11]). Results were also null for cardiovascular mortality in the 2 external cohorts (eg, HRs of IDH by the 2017 ACC/AHA definition were 1.17 [95% CI, 0.87-1.56] in the NHANES [n = 1012 events] and 1.02 [95% CI, 0.92-1.14] in CLUE II [n = 1497 events]).

CONCLUSIONS AND RELEVANCE

In this analysis of US adults, the estimated prevalence of IDH was more common when defined by the 2017 ACC/AHA BP guideline compared with the JNC7 guideline. However, IDH was not significantly associated with increased risk for cardiovascular outcomes.

Wideband External Pulse Recorded During Cuff Blood Pressure Measurement: A New Technique for Cardiovascular Assessment

Introduction

The wideband external pulse (WEP) recorded during blood pressure measurement reveals three components (K1, K2, K3). K1 is recorded with cuff pressure (CP) above systolic (SP).

Aim

To assess whether the K1 pattern contains information about the functional and structural properties of the cardiovascular system.

Methods

WEP analysis, echocardiography, carotid artery (CA) ultrasonography and applanation tonometry were conducted on 178 hypertensives. K1R, a feature of K1, was defined to provide a measure between the arterial incident and backward reflective waves.

Results

K1R was strongly correlated to vascular functional and structural parameters compatible with vascular effects of aging and hypertension. ANOVA analysis (K1R < 0 vs K1R > 0) showed that K1R < 0 participants: (1) were older, shorter, weighed less, had a smaller body surface area; (2) had higher SP, pulse (PP) and mean (MP) pressure, lower heart rate (HR), greater total peripheral resistance (TPR), lower cardiac output (CO), and a stiffer arterial system; (3) had a greater left ventricular (LV) relative wall thickness (LVRWT), carotid artery (CA) relative wall thickness (CARWT), CA far-wall intima-media thickness at end diastole (CIMTd) and CA cross-sectional area (CSA) (all p < 0.001). Regressions revealed that age, TPR, SP, gender, and HR predicted K1R (R² = 0.64) and that PP and K1R predicted CARWT (R² = 0.14). Logistic regression revealed that age, TPR, SP and aortic diameter differentiated K1R < 0 from K1R > 0 (Nagelkerke R² = 0.77).

Conclusions

K1R is related to vascular functional properties, with suggestive evidence that K1R is also related to vascular structural properties and perhaps subsequent cardiovascular risk.

Measuring arterial blood pressure in humans: Auscultatory and automatic measurement techniques for human biological field studies

Human biologists have been examining arterial blood pressure since they began studying the effects of the environment and culture on the health of diverse populations. The Korotkoff auscultatory technique with a trained observer and aneroid sphygmomanometer is the method of choice for blood pressure measurement in many bioanthropological field contexts. Korotkoff sounds (the first and fifth phases) are the preferred determinants of systolic and diastolic pressure, even in infants, children, pregnant women, and the elderly. Training of observers, positioning of individuals, and selection of cuff size are all essential for obtaining standardized measurements. Automatic electronic devices are increasingly being used for blood pressure measurement in human biological studies. The automatic monitors often use the oscillometric method for measuring pressure, but must be validated before use. The emergence of automatic ambulatory blood pressure monitors has opened another avenue of research on blood pressure in human biology, where allostasis and circadian responses to environmental change and real life behavioral challenges can be defined and evaluated, largely because there is now the ability to make multiple measurements over time and in varying contexts. Stand-alone automatic monitors can also be substituted for manual auscultated readings in field contexts, although in studies where participants measure their own pressure, education about how the devices work and protocol specifics are necessary. Finally, computer-driven plethysmographic devices that measure pressure in the finger are available to evaluate short-term reactivity to specific challenges.

Hypertension subtypes and risk of cardiovascular diseases in a Mongolian population, inner Mongolia, China

BACKGROUND

There have been no reports about the effects of hypertension subtypes on the future cardiovascular events among Mongolian people, China.

METHODS AND RESULTS

From June 2003 to July 2012, we conducted a prospective study to assess the association of hypertension subtypes with future risk of cardiovascular events including stroke and coronary heart disease among a Mongolian cohort of 2589 adults in China. According to the baseline blood pressure levels, the subjects were divided into those with normal blood pressure, prehypertension, isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and combined systolic and diastolic hypertension (SDH). Cox proportional hazards models were used to evaluate the association between blood pressure subtypes and risk of cardiovascular diseases. After adjustment for age and gender, hazard ratios (95% confidence intervals) of cardiovascular diseases were 1.75 (0.92-3.33), 2.11 (0.95-4.70), 2.14 (1.01-4.56) and 5.31 (2.86-9.77) for pre-hypertension, ISH, IDH and SDH, respectively, compared with normal blood pressure. Furthermore, after adding other cardiovascular risk factors to adjustment, hazard ratios (95% confidence intervals) of cardiovascular diseases were 1.74 (0.92-3.31), 2.00 (0.88-4.54), 2.20 (1.02-4.74) and 4.92 (2.62-9.26) for pre-hypertension, ISH, IDH and SDH, respectively, compared with the normal blood pressure group.

CONCLUSIONS

IDH and SDH were significantly associated with the increased risk of cardiovascular diseases; this study suggests that carefully monitoring and actively treating the subjects with IDH should be an important strategy for CVD prevention among Mongolian population.

Hypertension Subtypes among Hypertensive Patients in Ibadan

Background. Certain hypertension subtypes have been shown to increase the risk for cardiovascular morbidity and mortality and may be related to specific underlying genetic determinants. Inappropriate characterization of subtypes of hypertension makes efforts at elucidating the genetic contributions to the etiology of hypertension largely vapid. We report the hypertension subtypes among patients with hypertension from South-Western Nigeria. Methods. A total of 1858 subjects comprising 76% female, hypertensive, aged 18 and above were recruited into the study from two centers in Ibadan, Nigeria. Hypertension was identified using JNCVII definition and was further grouped into four subtypes: controlled hypertension (CH), isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and systolic-diastolic hypertension (SDH). Results. Systolic-diastolic hypertension was the most prevalent. Whereas SDH (77.6% versus 73.5%) and IDH (4.9% versus 4.7%) were more prevalent among females, ISH (10.1% versus 6.2%) was higher among males (P = 0.048). Female subjects were more obese (P < 0.0001) and SDH was prevalent among the obese group. Conclusion. Gender and obesity significantly influenced the distribution of the hypertension subtypes. Characterization of hypertension by subtypes in genetic association studies could lead to identification of previously unknown genetic variants involved in the etiology of hypertension. Large-scale studies among various ethnic groups may be needed to confirm these observations.

Hypertension in the metabolic syndrome

Increased blood pressure is considered an important component of metabolic syndrome. More than 85% of those with metabolic syndrome, even in the absence of diabetes, have elevated blood pressure (BP) or hypertension. The association of elevated BP with the metabolic syndrome is strongly linked through the causative pathway of obesity. Hypertension is the leading metabolic syndrome risk factor that predisposes to increased cardiovascular morbidity and mortality, and is additionally an important risk factor for development of chronic kidney disease in the presence of obesity, the metabolic syndrome, and microalbuminuria. Control of blood pressure in persons with the metabolic syndrome may prevent a significant number of coronary heart disease events. The primary modality of treatment is lifestyle intervention with reduced caloric intake and increased physical activity. Pharmacologic intervention is indicated on the basis of the severity of BP elevation, associated cardiovascular risk factors, and the presence of target organ damage.

The importance of diastolic blood pressure in predicting cardiovascular risk

Brachial systolic blood pressure (SBP) is the overall best predictor of future cardiovascular risk for the entire hypertensive population; however, there is much that can be learned from assessing diastolic blood pressure (DBP) in relation to simultaneous levels of SBP, because the former is not distorted by pressure amplification. Low DBP in very young adults (mean age 20 years), presenting as isolated systolic hypertension (ISH), results from elevation in stroke volume and/or arterial stiffness. This subtype of hypertension has a marked male predominance, occurs twice as frequently as essential hypertension, and is potentially not a benign condition. In contrast, isolated diastolic hypertension (IDH) in young adults (mean age of 40 years) with IDH occurs predominantly in men with a high prevalence of metabolic syndrome. Indeed, persons with IDH frequently evolve into systolic-diastolic hypertension and are potentially at increased risk for future diabetes and cardiovascular complications. The older age population with ISH and low DBP (mean age >/=60 years of age) has a high prevalence of left ventricular hypertrophy, increased ventricular-arterial stiffness, and a tendency for diastolic dysfunction and heart failure. Finally, concordant very high DBP, especially in older persons, defines potential hypertensive urgencies, emergencies, secondary forms of hypertension, and other high peripheral resistance states.

Hypothesis: it is time to reconsider phenotypes in hypertension

The study of genes and mechanisms associated with hypertension is hampered by the heterogeneity of hypertensive patients. Refining the definition of hypertension is a potential means of improving the clarity of mechanistic studies, but the lack of intermediate phenotypes hinders the assessment of causal relationships. Looking at younger individuals and hemodynamic subsets of hypertension is one such refinement. The authors argue that the separate analysis of patients with isolated diastolic hypertension, predominantly diastolic hypertension, and isolated systolic hypertension in the young in combination with common biomarkers may be an initial step to decrease heterogeneity within patient subsets, thus providing new avenues for genetic and pathophysiological studies.

The study of aortic stiffness in different hypertension subtypes in dialysis patients

The aim of this study was to validate whether differences in aortic stiffness are responsible for the differences in cardiovascular mortality among hypertension subtypes. Twenty hundred and fifty continuous ambulatory peritoneal dialysis patients were included in the present study. They were classified into four groups: normotensives (n=92) with systolic blood pressure (SBP) <140 mmHg and diastolic blood pressure (DBP) <90 mmHg; isolated systolic hypertensives (ISH, n=84) with SBP > or =140 mmHg and DBP <90 mmHg; isolated diastolic hypertensives (IDH, n=21) with SBP <140 mmHg and DBP > or =90 mmHg; and systolic-diastolic hypertensives (SDH, n=53) with SBP > or =140 mmHg and DBP > or =90 mmHg. Aortic stiffness was assessed by pulse pressure, central pressure parameters and pulse wave velocity. The IDH group had more male patients and a lower mean age than the other groups. The percentage of diabetes in the ISH group was higher than that in the other groups. The comparisons of aortic stiffness showed that the ISH and SDH groups had higher aortic stiffness than the normotension and IDH groups. The aortic stiffness in the ISH group was also higher than that in the SDH group, but there was no significant difference in aortic stiffness between the normotension and IDH groups. In conclusion, this study showed that aortic stiffness was significantly different among different hypertension subtypes, which might be an underlying cause of the differences in cardiovascular mortality among the hypertension subtypes.

Blood pressure categories, hypertensive subtypes, and the metabolic syndrome

BACKGROUND

Elevated blood pressure (BP) is one element of metabolic syndrome (MetS); however, the relation of various BP categories and hypertension subtypes to the likelihood of having MetS is not well defined.

METHODS

We determined the odds of MetS, defined by the National Cholesterol Education Program, in various BP categories from a cross-sectional study of 5968 individuals aged at least 18 years and untreated for hypertension (weighted to 124.7 million) in the National Health and Nutrition Examination Survey, 1999-2002. Nonhypertensive BP categories were optimal, normal, and high-normal BP, according to JNC-VI classification. Hypertension consisted of three subtypes: isolated diastolic hypertension (IDH), systolic-diastolic hypertension (SDH), and isolated systolic hypertension (ISH).

RESULTS

Among those with hypertension and MetS, 25.3% had IDH, 20.2% had SDH, and 54.5% had ISH. The MetS prevalence in nontreated persons was 5.8% for optimal BP, 9.1% for normal BP, 38.2% for high-normal BP, 45.9% for IDH, 44.3% for SDH, and 43.9% for ISH. Risk factor odds ratios (95% confidence intervals; reference group, optimal BP), adjusted for age, sex, total cholesterol, and smoking, were 1.6 (1.2-2.2) for normal BP, 9.4 (6.9-12.7) for high-normal BP, 14.7 (8.9-24.0) for IDH, 12.2 (7.2-20.8) for SDH, and 10.2 (7.0-14.9) for ISH (all P < 0.01); odds ratios were higher for women in all categories.

CONCLUSIONS

Despite having the lowest mean age, IDH subtype is associated with greatest likelihood of MetS. The high frequency of ISH in the hypertensive population, however, makes ISH the most common hypertensive subtype in persons with MetS.

What is the most important component of blood pressure: systolic, diastolic or pulse pressure?

PURPOSE OF REVIEW

Diastolic blood pressure has traditionally been considered the most important component of blood pressure and the primary target of antihypertensive therapy. However, over 30 years ago important epidemiological studies pointed out the importance of systolic blood pressure, and research during the 1990s has strengthened this view. Unlike diastolic blood pressure, systolic blood pressure increases progressively with age, and in the ageing societies elevated systolic pressure is the most common form of hypertension. The characteristic changes of systolic and diastolic blood pressure with age lead to increases in pulse pressure (systolic minus diastolic), which has emerged as a new, potentially independent risk factor. In this review we compare the relative importance of various blood pressure components.

RECENT FINDINGS

Generally, in studies in which readings of systolic and diastolic blood pressure have been compared, systolic blood pressure has been a better predictor of risk. Moreover, isolated systolic hypertension predicts risk better than isolated diastolic hypertension, and the treatment of both isolated systolic hypertension and combined hypertension has reduced cardiovascular events. There are no treatment studies of isolated diastolic hypertension. Pulse pressure reflects stiffening of large arteries and is associated with several cardiovascular risk factors. Pulse pressure also predicts events in epidemiologic studies, but elucidation of an independent role is hampered by the close correlation between pulse pressure and systolic blood pressure.

SUMMARY

Epidemiological and treatment studies suggest that systolic blood pressure should be the primary target of antihypertensive therapy, although consideration of systolic and diastolic pressure together improves risk prediction. The greatest practical concern at the moment is the undertreatment of hypertension, especially systolic, and total cardiovascular risk.

Isolated diastolic hypertension, pulse pressure, and mean arterial pressure as predictors of mortality during a follow-up of up to 32 years

OBJECTIVE

To compare mortality associated with various blood pressure components in middle-aged men during up to 32 years of follow-up.

DESIGN

A prospective cohort study.

SETTING

Helsinki, Finland.

PARTICIPANTS

We studied 3267 initially healthy men, aged 30-45 years, who participated in health check-ups from 1964 onwards.

MAIN OUTCOME MEASURES

Cox regression was used to relate baseline blood pressure components to all-cause (n = 701) and cardiovascular disease (CVD) mortality (n = 325).

RESULTS

Systolic (SBP) and diastolic (DBP) blood pressures, pulse pressure and mean arterial pressure singly predicted CVD mortality. With SBP 160 mmHg and DBP 90 mmHg as cut-off values, four blood pressure subgroups were identified: normotension (n = 1919), isolated systolic hypertension (ISH, n = 17), isolated diastolic hypertension (IDH, n = 1013), and combined systolic and diastolic hypertension (SDH, n = 318). IDH was subdivided into IDH-1 with SBP 140-159 mmHg (n = 667) and IDH-2 with SBP less than 140 mmHg (n = 346). With normotension as reference, only SDH and IDH-1 predicted CVD mortality [relative risk (RR) 2.71, 95% confidence interval (CI) 2.00 to 3.66, and RR 1.39, 95% CI 1.04 to 1.87, respectively]. Risk with IDH-2 (RR 1.14, 95% CI 0.77 to 1.69) was not statistically significant. SDH and IDH-1, but not IDH-2, were also associated with increased all-cause mortality risk. Use of antihypertensive medication did not explain the results.

CONCLUSION

These results demonstrate the often neglected role of SBP in predicting long-term CVD risk in middle-aged men. When SBP is less than 140 mmHg, IDH is not associated with significantly increased risk of mortality. Administrative guidelines, which affect population health, should also take due note of SBP.

Target blood pressure for antihypertensive therapy in patients with proteinuric renal disease

The Modification of Diet in Renal Disease (MDRD) study showed for the first time that controlling blood pressure is critically important in slowing the progression of proteinuric renal disease (24-h proteinuria of 1.0 g or more). Furthermore, it was found that the greater proteinuria, the more important it was to achieve excellent blood pressure control. The MDRD analysis also suggested that this paradigm may be particularly important for blacks with proteinuric renal disease. Surprisingly, the MDRD data showed that a blood pressure of 125/75 mm Hg was superior to a blood pressure of 135/85 mm Hg in slowing the progression of renal disease. Thus, so-called hypercontrol of blood pressure is needed to slow the progression of proteinuric renal disease. Studies in patients with diabetic glomerulosclerosis also have provided evidence as to the importance of achieving the low blood pressure goal to slow the progression of the glomerulopathy. In summary, strict control of blood pressure (125/75 mm Hg or less, if tolerated) is recommended to slow the progression of proteinuric renal disease. Furthermore, the greater the proteinuria, the more important it is to achieve this target blood pressure to slow the progression of renal disease.