Usual Diastolic Blood Pressure Research Articles

Midlife blood pressure is associated with the severity of white matter hyperintensities: analysis of the UK Biobank cohort study.

AimsWhite matter hyperintensities (WMH) progress with age and hypertension, but the key period of exposure to elevated blood pressure (BP), and the relative role of systolic BP (SBP) vs. diastolic BP (DBP), remains unclear. This study aims to determine the relationship between WMH and concurrent vs. past BP. Methods and results UK Biobank is a prospective community-based cohort of 40–69-year olds from 22 centres, with magnetic resonance imaging in a subgroup of over 40 000 people at 4–12 years after baseline assessment. Standardized associations between WMH load (WMH volume normalized by total white matter volume and logit-transformed) and concurrent vs. past BP were determined using linear models, adjusted for age, sex, cardiovascular risk factors, BP source, assessment centre, and time since baseline. Associations adjusted for regression dilution bias were determined between median WMH and usual SBP or DBP, stratified by age and baseline BP.In 37 041 eligible participants with WMH data and BP measures, WMH were more strongly associated with concurrent SBP [DBP: β = 0.064, 95% confidence interval (CI) 0.050–0.078; SBP: β = 0.076, 95% CI 0.062–0.090], but the strongest association was for past DBP (DBP: β = 0.087, 95% CI 0.064–0.109; SBP: β = 0.045, 95% CI 0.022–0.069), particularly under the age of 50 (DBP: β = 0.103, 95% CI 0.055–0.152; SBP: β = 0.012, 95% CI −0.044 to 0.069). Due to the higher prevalence of elevated SBP, median WMH increased 1.126 (95% CI 1.107–1.146) per 10 mmHg usual SBP and 1.106 (95% CI 1.090–1.122) per 5 mmHg usual DBP, whilst the population attributable fraction of WMH in the top decile was greater for elevated SBP (19.1% for concurrent SBP; 24.4% for past SBP). Any increase in BP, even below 140 for SBP and below 90 mmHg for DBP, and especially if requiring antihypertensive medication, was associated with increased WMH.ConclusionsWMH were strongly associated with concurrent and past elevated BP with the population burden of severe WMH greatest for SBP. However, before the age of 50, DBP was more strongly associated with WMH. Long-term prevention of WMH may require control of even mildly elevated midlife DBP.

Treatment of hypertension in patients with coronary artery disease: a scientific statement from the American Heart Association, American College of Cardiology, and American Society of Hypertension.

1. Relationship Between Hypertension and CAD e437 2. Prevention of Cardiovascular Events in Patients With Hypertension and CAD e443 3. BP Goals e445 4. Management of Hypertension in Patients With CAD and Stable Angina e449 5. Management of Hypertension in Patients With ACS e451

Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies

The age-specific relevance of blood pressure to cause-specific mortality is best assessed by collaborative meta-analysis of individual participant data from the separate prospective studies. Information was obtained on each of one million adults with no previous vascular disease recorded at baseline in 61 prospective observational studies of blood pressure and mortality. During 12.7 million person-years at risk, there were about 56000 vascular deaths (12000 stroke, 34000 ischaemic heart disease [IHD], 10000 other vascular) and 66000 other deaths at ages 40-89 years. Meta-analyses, involving "time-dependent" correction for regression dilution, related mortality during each decade of age at death to the estimated usual blood pressure at the start of that decade. Within each decade of age at death, the proportional difference in the risk of vascular death associated with a given absolute difference in usual blood pressure is about the same down to at least 115 mm Hg usual systolic blood pressure (SBP) and 75 mm Hg usual diastolic blood pressure (DBP), below which there is little evidence. At ages 40-69 years, each difference of 20 mm Hg usual SBP (or, approximately equivalently, 10 mm Hg usual DBP) is associated with more than a twofold difference in the stroke death rate, and with twofold differences in the death rates from IHD and from other vascular causes. All of these proportional differences in vascular mortality are about half as extreme at ages 80-89 years as at ages 40-49 years, but the annual absolute differences in risk are greater in old age. The age-specific associations are similar for men and women, and for cerebral haemorrhage and cerebral ischaemia. For predicting vascular mortality from a single blood pressure measurement, the average of SBP and DBP is slightly more informative than either alone, and pulse pressure is much less informative. Throughout middle and old age, usual blood pressure is strongly and directly related to vascular (and overall) mortality, without any evidence of a threshold down to at least 115/75 mm Hg.

The PROGRESS Trial: Preventing Strokes by Lowering Blood Pressure in Patients With Cerebral Ischemia

A blood pressure is an unhealthy thing to have, to a large extent. Prospective population-based observational studies have shown a continuous, positive relationship between blood pressure and the risk of stroke or other major vascular events. There is no “safe” level of blood pressure below which the risk ceases to diminish. The association is even stronger than one might surmise from casual measurements, because of regression to the mean on subsequent readings. After appropriate correction, prolonged differences in usual diastolic blood pressure of 5, 7.5, and 10 mm Hg are respectively associated with at least 34%, 46%, and 56% relative risk reduction of stroke.1,2 The effectiveness of antihypertensive treatment in the primary prevention of stroke leaves no doubt about the causality of the relationship: systematic reviews show that a diastolic blood pressure reduction of 5 to 6 mm Hg results in a large decrease in stroke rate, in the order of 35% to 50%.3,4 Until now, the question remained whether blood pressure reduction was equally beneficial in patients after a transient ischemic attack (TIA) or a stroke. Theoretically, irreparable damage might already have occurred at the time of the first manifestation of cerebrovascular disease. A slightly crude analogy is that abstaining from cigarettes greatly improves prognosis in the general population but not much in patients with bronchial carcinoma. Systematic reviews showed equivocal benefit of blood pressure reduction in 4 clinical trials in which an episode of brain ischemia was the qualifying event.5 In subsets of patients with previous stroke from trials of antihypertensive treatment in general, the evidence was somewhat more robust, but not for normotensive patients.6 Therefore the recently published PROGRESS trial can be regarded as an impressive undertaking.7 The target population consisted mostly of patients with ischemic stroke, brain TIA, or transient monocular …

The Associations of Diastolic Blood Pressure with the Risk of Stroke in Western and Eastern Populations

This paper reviews evidence from two overviews of prospective, observational studies of the association of diastolic blood pressure (DBP) with the risk of stroke in populations from the US and Europe and populations from China and Japan. The Western overview included seven studies involving a total of 405,511 individuals. During a mean follow-up period of 11 years, 843 strokes were observed. The Eastern overview included 18 cohorts involving a total of 124,774 participants. During a mean follow-up duration of 9 years, 1,798 strokes were observed. The shape of the association between usual DBP and the risk of stroke was similar in Western and Eastern populations, but in Eastern populations the size of the association was about 50% steeper than that in Western populations. This may be due, at least in part, to cerebral haemorrhage comprising a greater proportion of total stroke in Eastern populations. This finding, together with the high stroke rates in many Eastern Asian populations, suggests that the potential benefits of blood pressure lowering may be greater in Eastern Asia.

Hypertension and cardiovascular disease risk in women.

Hypertension and cardiovascular disease risk in women.

Primary and secondary prevention of stroke.

Data from prospective observational studies indicate that usual levels of blood pressure are directly and continuously related to the risk of stroke. a prolonged difference in usual diastolic blood pressure levels of just 5 mmHg would eventually confer about a one-third difference in stroke risk, with similar proportional effects in hypertensives and non-hypertensives. The results of randomised trials of blood pressure lowering drugs in hypertensive patients suggest that much or all of this long-term potential stroke avoidance can be achieved within just a few years of beginning treatment. Overall in 17 randomised trials of antihypertensive treatment, a net blood pressure reduction of 10-12 mmHg systolic and 5-6 mmHg diastolic, conferred a reduction in stroke incidence of 38% SD 4, with similar reductions in fatal and non-fatal stroke. Additionally, the sizes of the reductions were similar in trials in mild, moderate or more severe hypertension, in trials in older or younger patients and in trials in patients with or without a history of cerebrovascular disease. Because the proportional effects of treatment were similar in all these groups, the absolute effects of treatment on stroke varied in direct proportion to the background risk of stroke. The greatest benefits were, therefore, observed among those with a history of cerebrovascular disease, those above the age of 60 years, and those with more severe hypertension.

Cholesterol, diastolic blood pressure, and stroke: 13 000 strokes in 450 000 people in 45 prospective cohorts

<h2>Abstract</h2> Individual studies of stroke have not clearly answered two questions: on the relation, if any, between total blood cholesterol and stroke; and on how the strength of the relation between diastolic blood pressure and stroke varies with age. The associations of blood cholesterol and diastolic blood pressure with subsequent stroke rates were investigated by review of 45 prospective observational cohorts involving 450 000 individuals with 5-30 years of follow-up (mean 16 years, total 7·3 million person-years of observation), during which 13 397 participants were recorded as having had a stroke. Most of these were fatal strokes in studies that recorded only mortality and not incidence, but about one-quarter were from studies that recorded both fatal and non-fatal strokes. After standardisation for age, there was no association between blood cholesterol and stroke except, perhaps, in those under 45 years of age when screened. This lack of association was not influenced by adjustment for sex, diastolic blood pressure, history of coronary heart disease, or ethnicity (Asian or non-Asian). However, because the types of the strokes were not centrally available, the lack of any overall relation might conceal a positive association with ischaemic stroke together with a negative association with haemorrhagic stroke. When the highest and the lowest of the six blood pressure categories were compared, the difference in usual diastolic blood pressure was 27 mm Hg (102 vs 75 mm Hg), and there was a fivefold difference in stroke risk. This fivefold difference was seen both in those with a pre-existing history of coronary heart disease and in those without it. The proportional difference in stroke risk, however, was more extreme in middle than in old age. Among those aged <45, 45-64, and 65+ when screened, the differences in the relative risks of stroke (between the highest diastolic blood pressure category and a combination of the lowest two categories) were tenfold, fivefold, and twofold, respectively. However, because the absolute stroke risks are greater in old age, the absolute differences in the annual stroke rates showed an opposite pattern, being 2, 5, and 8 per thousand, respectively. This suggests that the effects of therapeutic blood pressure reductions should be assessed separately in middle age and in old age.

Hypertension and coronary artery disease in non-insulin dependent diabetes--cause and effect?

There is a log-linear increase in the risk of coronary heart disease with elevation of levels of blood pressure. Allowing for the phenomenon of regression dilution bias, this corresponds to around a 20 to 25% increase in risk for each 5 to 6 mm Hg elevation in usual diastolic blood pressure. In diabetic subjects, a similar relationship occurs, but of somewhat lesser degree. Recent overviews of therapy suggest that in nondiabetics, reducing blood pressure reverses around 50% of the excess coronary heart disease risk, but this has not yet been conclusively shown in patients with diabetes. The reduction in risk with therapy is a prerequisite to defining the antecedent as a causal influence on outcome, but it is as likely that the incomplete reversibility of excess risk represents other pathways of connection between hypertension and coronary heart disease as a consequent of iatrogenic effects of current treatments. Several alternative mechanisms are outlined, and the suggestion is made that only in the context of randomized controlled studies could the possible benefits on coronary heart disease of agents influencing such mechanisms be assessed.

Factors Influencing Threshold and Choice of Treatment for Hypertension in NIDDM: Cardiovascular Factors

In nondiabetic populations, there is an approximately 40% increase in stroke risk and a 25% increase in coronary heart disease (CHD) risk with every 6-mmHg increase above 75 mmHg in usual diastolic blood pressure. Diabetes increases the risk of both conditions by two- to threefold, and in diabetic patients, hypertension further increases these risks. The benefits of lowering blood pressure in nondiabetic subjects have been subjected to meta-analysis, which has demonstrated benefits equivalent to 100% reversal of the excess risk for stroke but with only approximately 50% of CHD risk reversible after 2-3 yr of treatment. In these analyses, the benefit of treating diastolic blood pressure is similar at all levels greater than 90 mmHg. If these results are extrapolated to diabetic patients, possible benefits of therapy for mild hypertension could be two to three times greater than in nondiabetic subjects, but this could still correspond to 300 person-yr of treatment to prevent one nonfatal stroke and 2500 person-yr of treatment to prevent one CHD death, with treatment that may deleteriously affect quality of life in 36% of all diabetic patients. There may also be risks in treating patients with mild hypertension who have existing CHD or left ventricular hypertrophy, which are more common in diabetes. Despite the theoretical risk of deleterious changes in several cardiovascular risk factors with thiazides or beta-blockers, most of the newer agents have not yet been demonstrated to produce similar benefits to the large prospective studies in which the aforementioned agents have been used.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood pressure, stroke, and coronary heart disease: Part 2, short-term reductions in blood pressure: overview of randomised drug trials in their epidemiological context

There are 14 unconfounded randomised trials of antihypertensive drugs (chiefly diuretics or beta-blockers): total 37 000 individuals, mean treatment duration 5 years, mean diastolic blood pressure (DBP) difference 5-6 mm Hg. In prospective observational studies, a long-term difference of 5-6 mm Hg in usual DBP is associated with about 35-40% less stroke and 20-25% less coronary heart disease (CHD). For those dying in the trials, the DBP difference had persisted only 2-3 years, yet an overview showed that vascular mortality was significantly reduced (2p<0·0002); non-vascular mortality appeared unchanged. Stroke was reduced by 42% SD 6 (95% confidence interval 33-50%; 289 vs 484 events, 2p<0·0001), suggesting that virtually all the epidemiologically expected stroke reduction appears rapidly. CHD was reduced by 14% SD 5 (95% CI 4-22%; 671 vs 771 events, 2p<0·01), suggesting that just over half the epidemiologically expected CHD reduction appears rapidly. Although this significant CHD reduction could well be worthwhile, its size remains indefinite for most circumstances (though beta-blockers after myocardial infarction are of substantial benefit). At present, therefore, a sufficiently high risk of stroke (perhaps because of age, blood pressure, or, in particular, history of cerebrovascular disease) may be the clearest indication for antihypertensive treatment.

Blood pressure, stroke, and coronary heart disease: Part 1, prolonged differences in blood pressure: prospective observational studies corrected for the regression dilution bias

The associations of diastolic blood pressure (DBP) with stroke and with coronary heart disease (CHD) were investigated in nine major prospective observational studies: total 420 000 individuals, 843 strokes, and 4856 CHD events, 6-25 (mean 10) years of follow-up. The combined results demonstrate positive, continuous, and apparently independent associations, with no significant heterogeneity of effect among different studies. Within the range of DBP studied (about 70-110 mm Hg), there was no evidence of any "threshold" below which lower levels of DBP were not associated with lower risks of stroke and of CHD. Previous analyses have described the uncorrected associations of DBP measured just at "baseline" with subsequent disease rates. But, because of the diluting effects of random fluctuations in DBP, these substantially underestimate the true associations of the usual DBP (ie, an individual's long-term average DBP) with disease. After correction for this "regression dilution" bias, prolonged differences in usual DBP of 5,7·5, and 10 mm Hg were respectively associated with at least 34%, 46%, and 56% less stroke and at least 21%. 29%, and 37% less CHD. These associations are about 60% greater than in previous uncorrected analyses. (This regression dilution bias is quite general, so analogous corrections to the relations of cholesterol to CHD or of various other risk factors to C H D or to other diseases would likewise increase their estimated strengths.) The DBP results suggest that for the large majority of individuals, whether conventionally "hypertensive" or "normotensive", a lower blood pressure should eventually confer a lower risk of vascular disease.