On-treatment diastolic blood pressure and prognosis in systolic hypertension

BACKGROUND: It has been suggested that low diastolic blood pressure (BP) while receiving antihypertensive treatment (hereinafter called on-treatment BP) is harmful in older patients with systolic hypertension. We examined the association between on-treatment diastolic BP, mortality, and cardiovascular events in the prospective placebo-controlled Systolic Hypertension in Europe Trial. METHODS: Elderly patients with systolic hypertension were randomized into the double-blind first phase of the trial, after which all patients received active study drugs (phase 2). We assessed the relationship between outcome and on-treatment diastolic BP by use of multivariate Cox regression analysis during receipt of placebo (phase 1) and during active treatment (phases 1 and 2). RESULTS: Rates of noncardiovascular mortality, cardiovascular mortality, and cardiovascular events were 11.1, 12.0, and 29.4, respectively, per 1000 patient-years with active treatment (n = 2358) and 11.9, 12.6, and 39.0, respectively, with placebo (n = 2225). Noncardiovascular mortality, but not cardiovascular mortality, increased with low diastolic BP with active treatment (P < .005) and with placebo (P < .05); for example, hazard ratios for lower diastolic BP, that is, 65 to 60 mm Hg, were, respectively, 1.15 (95% confidence interval, 1.00-1.31) and 1.28 (95% confidence interval, 1.03-1.59). Low diastolic BP with active treatment was associated with increased risk of cardiovascular events, but only in patients with coronary heart disease at baseline (P < .02; hazard ratio for BP 65-60 mm Hg, 1.17; 95% confidence interval, 0.98-1.38). CONCLUSIONS: These findings support the hypothesis that antihypertensive treatment can be intensified to prevent cardiovascular events when systolic BP is not under control in older patients with systolic hypertension, at least until diastolic BP reaches 55 mm Hg. However, a prudent approach is warranted in patients with concomitant coronary heart disease, in whom diastolic BP should probably not be lowered to less than 70 mm Hg.     

The role of diastolic blood pressure when treating isolated systolic hypertension.

OBJECTIVE: To assess the role of treated diastolic blood pressure (DBP) level in stroke, coronary heart disease (CHD), and cardiovascular disease (CVD) in patients with isolated systolic hypertension (ISH). DESIGN: An analysis of the 4736 participants in the Systolic Hypertension in the Elderly Program (SHEP) was undertaken. The SHEP was a randomized multicenter double-blind outpatient clinical trial of the impact of treating ISH in men and women aged 60 years and older. MAIN OUTCOME MEASURES: Cox proportional hazards regression analysis, with DBP and systolic blood pressure (SBP) as time-dependent covariables. RESULTS: After adjustment for the baseline risk factors of race (black vs other), sex, use of antihypertensive medication before the study, a composite variable (diabetes, previous heart attack, or stroke), age, and smoking history (ever vs never) and adjustment for the SBP as a time-dependent variable, we found, for the active treatment group only, that a decrease of 5 mm Hg in DBP increased the risk for stroke (relative risk, [RR], 1.14; 95% confidence interval [CI], 1.05-1.22), for CHD (RR, 1.08; 95% CI, 1.00-1.16), and for CVD (RR, 1.11; 95% CI, 1.05-1.16). CONCLUSIONS: Some patients with ISH may be treated to a level that uncovers subclinical disease, and some may be overtreated. Further studies need to determine whether excessively low DBP can be prevented by more careful titration of antihypertensive therapy while maintaining SBP control. It is reassuring that patients receiving treatment for ISH never perform worse than patients receiving placebo in terms of CVD events.     

Treatment and blood pressure control in isolated systolic hypertension vs diastolic hypertension in primary care

Cross-sectional surveys on prevalence, treatment and control of hypertension could not satisfactorily distinguish between diastolic hypertension and isolated systolic hypertension because the definition of hypertension included patients under pharmacological treatment. We assessed the situation in the two types of hypertension in general practice in Belgium, based on current blood pressure (BP) measurements and on BP prior to the initiation of drug therapy. Participating physicians enrolled the first 15 at least 55-year-old men visiting the surgery, measured their BP and recorded data on medical history including pretreatment BP, drug utilization, cardiovascular risk factors and target organ damage. Diastolic hypertension was defined as diastolic BP> or =90 mmHg, irrespective of systolic BP, and isolated systolic hypertension as systolic BP > or =140 mmHg and diastolic BP < 90 mmHg. Among 3761 evaluable patients, 74% were hypertensive. Among the 1533 hypertensive patients in whom blood pressure was known prior to treatment (n=965) or who were untreated at the study visit (n=568), 1164 had diastolic hypertension and 369 isolated systolic hypertension. The prevalence of antihypertensive treatment was, respectively, 75 and 25% (P<0.001) in these two types of hypertension. The odds of being treated were independently determined by type of hypertension, severity of hypertension and level of risk (P<0.001). BP was controlled in 25% of all patients with diastolic hypertension and in 13% of all patients with isolated systolic hypertension (P<0.001). About half of the treated patients with systolic hypertension were on a diuretic and/or a calcium-channel blocker. In conclusion, isolated systolic hypertension is less frequently treated than diastolic hypertension, overall BP control is poor and actual drug therapy diverges from recommendations based on placebo-controlled intervention trials.     

Stroke risk in systolic and combined systolic and diastolic hypertension determined using ambulatory blood pressure. The Ohasama study

BACKGROUND: To investigate the risk of stroke in subjects with isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and combined systolic and diastolic hypertension (SDH) in a Japanese general population, we used 24-h ambulatory blood pressure (ABP) and casual-screening blood-pressure (CBP) readings. METHODS: Subtypes of hypertension were defined based on systolic blood pressure (SBP) >135 mm Hg or diastolic blood pressure (DBP) >80 mm Hg for 24-h ABP, and SBP >140 mm Hg or DBP >90 mm Hg for CBP. We obtained 24-h ABP and CBP data for 1271 (40% male) subjects aged > or =40 years (mean age, 61 years) without a history of symptomatic stroke; their stroke-free survival was then determined. The prognostic significance of each subtype of hypertension was determined by Cox proportional hazard analysis. RESULTS: There were 113 symptomatic strokes during follow-up (mean time, 11 years). Compared with normotension, among the hypertension subtypes determined by 24-h ABP, the adjusted relative hazards (RHs) of stroke were 2.24 for ISH (P = .002) and 2.39 for SDH (P = .0004). The association was less marked among subtypes determined by CBP (RH = 1.40 and P = .13 for ISH; RH = 2.07 and P = .017 for SDH). The IDH group was excluded from the Cox analysis because both the prevalence and the number of events were low in this group. CONCLUSIONS: Isolated systolic hypertension, as determined by 24-h ABP measurements, was associated with a high risk of stroke, similar to that found in SDH subjects; this suggests that the prognosis of hypertensive patients would be improved by focusing treatment on 24-h systolic ABP.     

低舒张压的单纯收缩期高血压研究新进展

在有些高龄患者中,会出现舒张压（DBP）＜60mmHg高血压患者,即低DBP的单纯收缩期高血压（ISH）。越来越多的证据表明DBP＜70mmHg对机体是不利的,而低DBP的ISH患者常具有更多的心血管危险因素和更多的心血管事件风险,成为老年高血压降压治疗的难点,使用硝酸酯类药物进行治疗可能是一个有益的选择。     

Prediction of cardiovascular events from systolic or diastolic blood pressure

Over time, a focus on blood pressure has transferred from diastolic pressure to systolic pressure. Formal analyses of differences in predictive value are scarce. Our goal of the study was whether office SBP adds prognostic information to office DBP and whether both 24‐h ambulatory SBP and 24‐h ambulatory DBP is specifically important. The authors examined 2097 participants from a population cohort recruited in Copenhagen, Denmark. Cause‐specific Cox regression was performed to predict 10‐year person‐specific absolute risks of fatal and non‐fatal cardiovascular (CV) events. Also, the time‐dependent area under the receiver operator curve (AUC) was utilized to evaluate discriminative ability. The calibration plots of the models (Hosmer‐May test) were calculated as well as the Brier score which combines (discrimination and calibration). Adding both 24‐h ambulatory SBP and 24‐h ambulatory diastolic blood pressure did not significantly increase AUC for CV mortality and CV events. Moreover, adding both office SBP and office DBP did not significantly improve AUC for both CV mortality and CV events. The difference in AUC (95% confidence interval; p‐value) was .26% (‐.2% to .73%; .27) for 10‐year CV mortality and .69% (‐.09% to 1.46%; .082) for 10‐year risk of CV events. The difference in AUC was .12% (‐.2% to .44%; .46) for 10‐year CV mortality and .04% (‐.35 to .42%; .85) for 10‐year risk of CV events. Moreover, for both CV mortality and CV events, office SBP did not improve prognostic information to office DBP. In addition, the Brier scores of office BP in both CV mortality and CV events were .078 and .077, respectively. Furthermore, the Brier scores were .077 and .078 in CV mortality and CV events of 24‐h ambulatory. For the average population as those participating in a population survey, the 10‐year discriminative ability for long‐term predictions of CV death and CV events is not improved by adding systolic to diastolic blood pressure. This finding is found for ambulatory as well as office blood pressure.     

Ascorbic acid status and subsequent diastolic and systolic blood pressure

Free radicals and oxidation are involved in several aspects of blood pressure physiology. We investigated the relationship between blood pressure and antioxidants, including plasma ascorbic acid (AscA), in a 17-week controlled-diet study. Study subjects included 68 men aged 30 to 59 years who had a mean diastolic blood pressure of 73.4 mm Hg and a mean systolic blood pressure of 122.2 mm Hg. One month of vitamin C depletion was followed by 1-month repletion with 117 mg/d, repeated twice. All food and drink were provided in the study. Subjects did not smoke or drink alcohol, all consumed fruits and vegetables, and body weight was maintained. Plasma was assayed periodically for AscA, alpha-tocopherol, carotenoids, and lipids. Plasma AscA was inversely related to diastolic blood pressure 1 month later (correlation -0.48, P:<0.0001). Persons in the bottom fourth of the plasma AscA distribution had >7 mm Hg higher diastolic blood pressure than did those in the top fourth of the plasma AscA distribution. Multivariate analysis with control for age, body mass index, other plasma antioxidants, and dietary energy, calcium, fiber, sodium, and potassium did not reduce the plasma AscA effect. One fourth of the variance in diastolic blood pressure was accounted for by plasma AscA alone. Plasma AscA was also significantly associated with systolic blood pressure in logistic regression. Vitamin C may be an important component of the effectiveness of fruits and vegetables in the reduction in blood pressure, and tissue AscA levels may be important in the maintenance of low blood pressure. Long-term intervention studies are warranted.     

Renin dependency of blood pressure in isolated systolic hypertension

The role of the renin system in the maintenance of the elevated systolic blood pressure in isolated systolic hypertension was investigated in 31 patients who received long-term treatment with propranolol (120 mg daily) and in another group of 22 patients with isolated systolic hypertension who received a test dose of captopril (25 or 50 mg). The greatest systolic blood pressure decrease (35 +/- 5 mm Hg) by propranolol occurred in the high-renin group (n = 9), and the smallest decrease (3 +/- 2 mm Hg) in the low-renin group (n = 9), whereas in the normal-renin group (n = 13), systolic blood pressure was decreased by propranolol by 22 +/- 5 mm Hg. For all the propranolol-treated patients, the decrement in the systolic blood pressure by propranolol was related to the control plasma renin activity (r = 0.63, p less than 0.01) and to the concurrent change in plasma renin activity (r = 0.70, p less than 0.001). Captopril decreased the systolic blood pressure by 55 +/- 10 mm Hg in the high-renin group (n = 11) and by 17 +/- 5 mm Hg in the normal-renin group (n = 6), whereas the smallest decrease (12 +/- 5 mm Hg) in systolic blood pressure occurred in the low-renin group (n = 5). In all the captopril-tested patients (n = 22), the decrease in systolic blood pressure by captopril was related to the control plasma renin activity (r = 0.75, p less than 0.001). These results indicate that the plasma renin activity value indicates the participation of the renin-angiotensin system in the maintenance of the elevated systolic blood pressure in patients with isolated systolic hypertension.     

Gene polymorphisms of the renin-angiotensin system and age-related changes in systolic and diastolic blood pressure in subjects with hypertension

BACKGROUND: Few studies have examined to what extent genes might modulate the changes of systolic and diastolic blood pressure (BP) with age although, in older populations, systolic BP and diastolic BP vary with age in opposite directions. METHODS: This study involved 205 men and 99 women with either systolic-diastolic or isolated systolic hypertension. Age was > 50 years. Using polymerase chain reaction, four gene polymorphisms related to the renin-angiotensin system were independently investigated in men and women. Adjustments to cardiovascular and renal risk factors as well to the sodium/potassium extracellular space ratio were performed. RESULTS: Regarding the angiotensin-converting enzyme (ACE) gene polymorphism, in men > 50 years of age, the slope (mm Hg per unit of age) of the age-diastolic BP (and not age-systolic BP) relationships significantly (P = .0092) differed between genotypes: - 0.79 +/- 0.15 (P < .0001) for the DD genotype, -0.53 +/- 0.10 for the ID genotype (P < .0001), and -0.23 +/- 0.11 for II genotypes (P = NS). Such findings were not observed in the female population in which the age-diastolic BP curves were substantially flatter than in men. No comparable results were observed for gene polymorphisms related either to angiotensinogen or to angiotensin II type 1 receptor. CONCLUSIONS: In men > 50 years of age, the ACE gene polymorphism modulates the physiologic age-induced reduction of diastolic BP. The D allele might contribute to enhance this reduction, a finding that needs confirmation using prospective studies.     

Feasibility of cuff-free measurement of systolic and diastolic arterial blood pressure

We validated a prototype cuff-free device for noninvasive estimation of blood pressure (BP). The system assumed a linear relation between BP values and the inverse of arterial blood pulse transit time, measured as time interval between the R wave on the electrocardiograph and the onset of the peripheral pulse wave on a finger plethysmogram. Thirty-three healthy subjects were analyzed at rest and during increasing stress exercise. To estimate subject-specific linear model parameters, the system was calibrated ad personam with reference to BP measures obtained by a cuff sphygmomanometer. High correlation values (R² = 0.89 and 0.78 for systolic and diastolic BP, respectively) and differences consistent with clinical requirements (mean discrepancy of −0.058 and −0.25 mm Hg; 95% confidence interval of −13.0 to +12.9 mm Hg and −11.3 to +10.8 mm Hg, for systolic and diastolic BP, respectively) were observed between device and reference measurements. Calibration parameter stability and accuracy level were confirmed in a midterm evaluation, 30 days after calibration. These findings suggest the suitability of the device for noninvasive BP monitoring and its potentiality for clinical applications. Improvements can be achieved by further investigation of the calibration procedure and sensor placement.     

Infradian awake and asleep systolic and diastolic blood pressure rhythms in humans

BACKGROUND: Blood pressure shows 24-h rhythms with a significant seasonal fluctuation. OBJECTIVES: To characterize 2-month to 12-month infradian rhythms in the mean awake and asleep systolic blood pressure (SBP) and diastolic blood pressure (DBP) in humans. METHODS: A total of 1689 participants underwent 24-h ambulatory blood pressure monitoring during different periods of the year. The mean daily temperature, humidity, barometric pressure and wind velocity values for the same time span and geographical location were obtained. Fourier analysis was used to fit 12-month, 6-month, 4-month, 3-month and 2-month rhythms to the mean awake and asleep SBP and DBP and to metereological variables. RESULTS: The awake mean SBP and DBP values showed significant 12-month and 3-month rhythms (respectively, R2 = 55%, P < 0.001 and R2 = 45% P < 0.001), with a peak in July (winter) and a trough-peak difference of 6.2 +/- 1.6 mmHg (P < 0.001, SBP) and 4.2 +/- 1.5 mmHg (P < 0.001, DBP). In contrast, asleep blood pressure means showed mainly 3-month rhythms (SBP, R2 = 19%, P < 0.02; DBP, R2 = 43% P < 0.02). Mean daily temperature and humidity showed at 12-month, 6-month, 4-month, 3-month and 2-month rhythms, barometric pressure showed 12-month and 6-month rhythms, and wind velocity showed 12-month and 3-month rhythms. Minimal temperature values and maximal humidity values coincided with elevated blood pressure values. CONCLUSION: Awake blood pressure means exhibited mainly circannual fluctuations while asleep blood pressure means showed principally 3-month rhythms. Infradian blood pressure variations correlated with some meteorological variables.     

Prognostic value of systolic and diastolic blood pressure in treated hypertensive men

BACKGROUND: The aim of this study was to assess the cardiovascular risk in hypertensive subjects according to systolic blood pressure (SBP) and diastolic blood pressure (DBP) levels. METHODS: The study sample consisted of 4714 hypertensive men, treated by their physician, who had a standard health checkup at the d'Investigations Préventives et Cliniques Center, Paris, France, between 1972 and 1988. Cardiovascular disease (CVD) and coronary heart disease (CHD) mortality were assessed for a mean period of 14 years. RESULTS: Among treated subjects, 85.5% presented uncontrolled values for SBP (> or = 40 mm Hg) and/or DBP (> or = 90 mm Hg). After adjustment for age and associated risk factors, these subjects presented an increased risk for CVD mortality (risk ratio [RR], 1.66; 95% confidence interval [CI], 1.04-2.64) and for CHD mortality (RR, 2.35; 95% CI, 1.03-5.35) compared with controlled subjects. After adjustment for age, associated risk factors, and DBP, and compared with subjects with SBP under 140 mm Hg, the RR for CVD mortality was 1.81 (95% CI, 1.04-3.13) in subjects with SBP between 140 and 160 mm Hg and 1.94 (95% CI, 1.10-3.43) in subjects with SBP over 160 mm Hg. By contrast, after adjustment for SBP levels, CVD risk was not associated with DBP. Compared with subjects with DBP under 90 mm Hg, RR for CVD mortality was 1.17 (95% CI, 0.80-1.70) in subjects with DBP between 90 and 99 mm Hg and 1.03 (95% CI, 0.67-1.56) in subjects with DBP over 100 mm Hg. Similar results were observed for CHD mortality. CONCLUSIONS: In hypertensive men treated in clinical practice, SBP is a good predictor of CVD and CHD risk. Diastolic blood pressure, which remains the main criterion used by most physicians to determine drug efficacy, appears to be of little value in determining cardiovascular risk. Evaluation of risk in treated individuals should take SBP rather than DBP values into account.     

Epidemiology of systolic and diastolic systemic blood pressure elevation in the elderly

The percentage of the U.S. population older than 65 years has increased faster than the U.S. population as a whole, from 8.1% in 1950 to 11.2% in 1979. Primary among the many factors contributing to increased life expectancy are the improved detection, treatment and control of blood pressure (BP), which has contributed to lower cardiovascular and cerebrovascular mortality in the elderly. The relation of elevated diastolic BP to increased risk of cardiovascular disease in the elderly is well documented; recent findings show increased risk associated with systolic hypertension, as well. More than half of the elderly population of 22 million has borderline or definite systemic hypertension. Almost 60% of the mortality associated with elevated BP is attributable to mild hypertension, i.e., diastolic BP of 90 to 104 mm Hg. In addition, more than 10% of persons older than 65 years have isolated systolic hypertension, i.e., greater than or equal to 160 mm Hg. The value of treating mild, moderate and severe elevation of diastolic BP in reducing mortality in the elderly is well known; the value of treating isolated systolic hypertension in this population is under investigation.     

血红蛋白与原发性高血压患者舒张压的相关性研究

目的探讨血红蛋白(Hb)与原发性高血压患者舒张压(DBP)的相关性。方法本研究为回顾性队列研究。连续纳入2016年1~12月在宣武医院就诊的未接受药物治疗的原发性高血压患者,检测所有患者生化指标及血常规。定义DBP≥90 mmHg为DBP升高,根据DBP水平分为DBP正常组(36例)和DBP升高组(69例)。应用pearson相关性分析和logistic回归分析Hb与DBP的相关性。结果共纳入105例患者,平均年龄(48.99±12.91)岁。DBP升高组体重、肌酐、谷丙转氨酶、白细胞计数、Hb、红细胞计数、红细胞压积、收缩压均高于DBP正常组,而年龄低于正常组,差异有统计学意义(均为P<0.05)。Pearson相关分析提示,Hb与DBP呈正相关(r=0.262,P=0.007)。多元线性回归分析提示,Hb(β=0.117,P<0.05)、谷丙转氨酶(β=0.086,P<0.05)与DBP呈正相关,而年龄(β=-0.234,P<0.05)与DBP呈负相关,logistic回归分析发现Hb是原发性高血压患者DBP的危险因素(比值比=1.049,P<0.05)。结论Hb与原发性高血压患者DBP呈正相关,是原发性高血压患者DBP的独立危险因素。     

Drug treatment of hypertension: the reduction of pulse pressure does not necessarily parallel that of systolic and diastolic blood pressure

Drug treatment of hypertension reduces systolic and diastolic blood pressure according to a well-established dose-response curve. Whether there is a parallel decrease in mean blood pressure and pulse pressure has not been investigated in the past Recent analysis of the literature and personal work indicates that, during drug treatment of hypertension, a significant decrease in systolic and diastolic blood pressure may be associated with an unchanged pulse pressure, a situation that might contribute to maintaining cardiovascular risk.     

高血压的数字化管理改善收缩压变异性

平均收缩压相比,较高的收缩压变异性已被证明是全因和心血管病死亡率、脑卒中和心脏病的更好的预测因子。研究者评估了数字高血压治疗计划对803例长期高血压患者的收缩压变异性的影响,这些患者在入组前接受初级保健医生至少12个月的治疗(平均为4.7年)。血压读数通过使用数据连接的血压装置直接从家中传输。药物调整和生活方式指导通过一个由药剂师和健康顾问组成的专门团队提供。使用每个个体所有收缩压数值的标准差计算收缩压变异性,并按四分位数分组。