Systolic and diastolic blood pressure, pulse pressure, and mean arterial pressure as predictors of cardiovascular disease risk in Men

We compared systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and mean arterial pressure (MAP) in predicting the risk of cardiovascular disease (CVD), stratifying results at age 60 years, when DBP decreases while SBP continues to increase. We prospectively followed 11 150 male physicians with no history of CVD or antihypertensive treatment through the 2-year questionnaire, after which follow-up began. Reported blood pressure was averaged from both the baseline and 2-year questionnaires. During a median follow-up of 10.8 years, there were 905 cases of incident CVD. For men aged <60 years (n=8743), those in the highest versus lowest quartiles of average SBP (>/=130 versus <116 mm Hg), DBP (>/=81 versus <73 mm Hg), and MAP (>/=97 versus <88 mm Hg) had relative risks (RRs) of CVD of 2.16, 2.23, and 2.52, respectively. Models with average MAP and PP did not add information compared with models with MAP alone (P>0.05). For men aged >/=60 years (n=2407), those in the highest versus lowest quartiles of average SBP (>/=135 versus <120 mm Hg), PP (>/=55 versus <44 mm Hg), and MAP (>/=99 versus <91 mm Hg) had RRs of CVD of 1.69, 1.83, and 1.43, respectively. The addition of other blood pressure measures did not add information compared with average SBP or PP alone (all P>0.05). These data suggest that average SBP, DBP, and MAP strongly predict CVD among younger men, whereas either average SBP or PP predicts CVD among older men. More research should distinguish whether MAP, highly correlated with SBP and DBP, better predicts CVD.     

Family history of diabetes modifies the effect of blood pressure for incident diabetes in Middle Eastern women: Tehran Lipid and Glucose Study

Elevated blood pressure (BP) may lead to incident diabetes. However, data about the effect of different BP components on incident diabetes in Middle Eastern women is lacking. We evaluated systolic BP (SBP), diastolic BP (DBP), pulse pressure (PP) and mean arterial pressure (MAP) as independent predictors of diabetes in Iranian women. We performed a population-based prospective study among 3028 non-diabetic women, aged ≥20 years. Odds ratios (ORs) of diabetes were calculated for every 1 s.d. increase in SBP, DBP, PP and MAP. During ≈6 years of follow-up, 220 women developed diabetes. There were significant interactions between family history of diabetes and SBP, PP and MAP (P≤0.01) in predicting incident diabetes. In women without a family history of diabetes, all BP components were significantly associated with diabetes in the age-adjusted model; the risk factor-adjusted ORs were significant (P<0.05) for SBP, PP and MAP (1.30, 1.34 and 1.27, respectively) with similar predictive ability (area under the receiver operating characteristic curve ≈83%). In women with family history of diabetes, in the age-adjusted model, SBP, DBP and MAP were associated with diabetes; in multivariable model, they were not independent predictors of diabetes. In conclusion, in women without family history of diabetes, SBP, PP and MAP, were independent predictors of diabetes with almost similar predictive ability; hence, in the evaluation of the risk of BP components for prediction of diabetes, the presence of family history of diabetes should be considered.     

Pulse pressure compared with other blood pressure indexes in the prediction of 25-year cardiovascular and all-cause mortality rates: The Chicago Heart Association Detection Project in Industry Study

We compared the relations of 4 blood pressure (BP) indexes (pulse pressure [PP], systolic BP [SBP], diastolic BP [DBP], and mean arterial pressure [MAP]) with 25-year mortality rates for coronary heart disease (CHD), cardiovascular disease (CVD), and all causes in younger, middle-aged, and older men and women by using data from a long-term prospective epidemiological study of employed persons who were screened between 1967 and 1973. A single supine BP measurement was obtained at baseline. Vital status was determined through 1995. We report on 5 groups (total, 28 360 participants) consisting of men age 18 to 39, 40 to 59, and 60 to 74 years and of women age 40 to 59 and 60 to 74 years who were not receiving antihypertensive treatment, had no history of CHD, and did not have diabetes. Cox proportional hazards analyses were used to determine multivariate-adjusted hazard ratios with a 1-SD higher value for each BP index; Wald chi(2) tests were used to compare the strength of relations. Relations of PP were less strong than were those of SBP for all end points in all age/gender groups. SBP or MAP showed the strongest relations to all end points in all age/gender groups (hazard ratio, 1.17 to 1.36). The relations of SBP to death were stronger than were those of DBP, except for middle-aged men and for CVD in women. DBP showed significant positive associations with death, after control for SBP, in middle-aged participants. In conclusion, these data indicate that the long-term risk of high BP should be assessed mainly on the basis of SBP or of SBP and DBP together, not on the basis of PP, in apparently healthy adults.     

Age-dependent associations between blood pressure and coronary artery calcification in asymptomatic adults

OBJECTIVE: The age-dependent roles of the components of blood pressure (BP) in the development of coronary artery calcification (CAC) are poorly understood. DESIGN: We examined systolic (SBP), diastolic (DBP), mean arterial pressure (MAP) and pulse pressure (PP) as predictors of CAC in 830 asymptomatic, non-diabetic participants in a community-based study who were aged > or = 30 years and free of antihypertensive therapy or known cardiovascular disease. METHODS: CAC was measured with electron beam computed tomography. Tobit regression was used in two age groups (< 50 years and > or = 50 years) to evaluate the relationship of BP components with presence and quantity of CAC, adjusting for traditional coronary artery disease (CAD) risk factors. RESULTS: Among those aged < 50 years, CAC was positively associated with SBP, DBP and MAP, considering each pressure individually and DBP was the strongest predictor (P = 0.0088). Among those aged > or = 50 years, CAC was positively associated with SBP (P = 0.0257) and PP (P = 0.0028), considered individually. When SBP and DBP were in the same model, presence and CAC quantity were positively associated with SBP (P = 0.0024) and negatively with DBP (P = 0.0401), favoring PP as the best predictor of CAC. CONCLUSIONS: SBP, DBP and PP have age-dependent roles in the prediction of CAC similar to their roles in prediction of future CAD events. These observations provide new evidence supporting the measurement of CAC as a surrogate of target organ disease and subsequently, as a predictor of increased risk of future CAD events.     

Comparison of four blood pressure indexes for the prediction of 10-year stroke risk in middle-aged and older Asians

Information has been sparse on the comparison of 4 blood pressure (BP) indexes (systolic BP [SBP], diastolic BP [DBP], pulse pressure [PP], and mean BP [MBP]) in relation to long-term stroke incidence, especially in middle-aged and older Asian people. A prospective cohort study was performed in 4989 Japanese (1523 men and 3466 women) aged 35 to 79 at baseline with 10 years of follow-up. End points included stroke incidence (total, ischemic, and hemorrhagic). Multivariate-adjusted hazard ratios with a 1-SD higher value for each BP index were determined by Cox proportional hazard analyses; Wald chi2 tests were used to compare the strength of relationships. Analyses were also done for each of 4 age-gender groups consisting of men and women aged 35 to 64 and 65 to 79 years. During follow-up, 132 participants developed stroke. Adjusted hazard ratios for all strokes were 1.68 for SBP, 1.72 for DBP, and 1.80 for MBP, which were higher than that for PP (1.34). SBP and DBP were related positively to stroke risk after adjustment of each other. PP was not the strongest predictor in any age-gender groups among 4 BP indexes. In men aged 65 to 79 years, SBP showed the strongest relationship to all stoke risk (hazard ratio 1.62) among 4 BP indexes. In women aged 65 to 79 years, hazard ratios for all strokes were 2.48 for MBP, 2.46 for DBP, 2.25 for SBP, and 1.57 for PP. The long-term incident stroke risk of high BP in Asians should be assessed by SBP and DBP together, or by MBP, not by PP.     

Predicting stroke using 4 ambulatory blood pressure monitoring-derived blood pressure indices: the Ohasama Study

We investigated the association between stroke and blood pressure (BP) indices (systolic BP [SBP], diastolic BP [DBP], mean BP [MBP], and pulse pressure [PP]) determined by ambulatory BP monitoring. The predictive power for stroke of these indices was compared in the general Japanese population. We obtained ambulatory BP data in 1271 subjects (40% men) aged > or = 40 (mean: 61) years. During a mean follow-up of 11 years, 113 strokes were observed. The multivariate adjusted relative hazard and likelihood ratio for a 1-SD increase for each BP index was determined by Cox proportional hazard regression. Comparison of the likelihood ratio between Cox models including 2 indices and those including 1 index indicated that PP was significantly less informative than other indices (P<0.01 when adding MBP, SBP, or DBP to the PP model; P>0.09 when adding PP to the model including another index). However, after removing age from covariates, PP became more informative than DBP and MBP (P<0.0001 when adding PP to the MBP or DBP model, whereas SBP was more informative than PP even after removing age; P<0.05 when adding SBP to the PP model). In conclusion, PP was the weakest predictor of stroke. Exclusion of age from covariates increased the predictive power of PP, suggesting that the stroke risk associated with PP reflected the risk of aging per se.     

Association of NT-ProBNP,Blood Pressure,and Cardiovascular Events: The ARIC Study

BackgroundAlthough intensive blood pressure reduction has cardiovascular benefits, the absolute benefit is greater in those at higher cardiovascular disease (CVD) risk.ObjectivesThis study examined whether N-terminal pro–B-type natriuretic peptide (NT-proBNP) helps identify subjects at higher risk for CVD events across systolic blood pressure (SBP), diastolic blood pressure (DBP), or pulse pressure (PP) categories.MethodsParticipants from the ARIC (Atherosclerosis Risk In Communities) study visit 4 (1996 to 98) were grouped according to SBP, DBP, or PP categories and further stratified by NT-proBNP categories. Cox regression models were used to estimate hazard ratios for incident CVD (coronary heart disease, ischemic stroke, or heart failure hospitalization) and mortality across combined NT-proBNP and/or BP categories, adjusting for CVD risk factors.ResultsThere were 9,309 participants (age: 62.6 ± 5.6 years; 58.3% women) with 2,416 CVD events over a median follow-up of 16.7 years. Within each SBP, DBP, or PP category, a higher category of NT-proBNP (100 to <300 or 300 pg/ml, compared with NT-proBNP <100 pg/ml) was associated with a graded increased risk for CVD events and mortality. Participants with SBP 130 to 139 mm Hg but NT-proBNP ≥300 pg/ml had a hazards ratio of 3.4 for CVD (95% confidence interval: 2.44 to 4.77) compared with a NT-proBNP of <100 pg/ml and SBP of 140 to 149 mm Hg.ConclusionsElevated NT-proBNP is independently associated with CVD and mortality across SBP, DBP, and PP categories and helps identify subjects at the highest risk. Participants with stage 1 hypertension but elevated NT-proBNP had greater cardiovascular risk compared with those with stage 2 SBP but lower NT-proBNP. Future studies are needed to evaluate use of biomarker-based strategies for CVD risk assessment to assist with initiation or intensification of BP treatment.     

Significance of mean blood pressure for blood pressure control

The significance of pulse pressure (PP) and mean blood pressure (MBP) for blood pressure (BP) control is unclear. The aim of this study was to examine the relationship between PP and MBP and BP control. We obtained home BP measurements for 117 patients aged 40-75 years with either office systolic BP (SBP) >or= 140 mmHg or office diastolic BP (DBP) >or= 90 mmHg. Patients were treated with 1 to 2 antihypertensive drugs for 6 months to achieve home SBP < 135 mmHg and home DBP < 85 mmHg. At follow-up, 72 patients were taking a single drug with good BP control, 23 were taking two drugs with good BP control, and 22 were taking two drugs without good BP control. Although office SBP and DBP at baseline were similar in the three groups, home SBP and DBP at baseline in the single drug group were lowest among the three groups (P < 0.01). Home MBP at baseline in the single drug group was lowest among the three groups (P < 0.01). Home PP at baseline was highest in the two-drug without good control group (P < 0.001). In multivariate logistic regression analysis, only home MBP at baseline was significantly correlated with a lack of BP control. Home MBP rather than home PP is associated with achieving adequate BP control.     

Is systolic blood pressure below 150 mm Hg an appropriate goal for primary prevention of cardiovascular events among elderly population?

Recently, Joint National Committee has changed the optimal therapeutic goal of systolic blood pressure (SBP) up to 150 mm Hg for elderly population. We aimed to investigate impact of different blood pressure (BP) categories on risk of developing cardiovascular disease (CVD) and mortality among elderly. The present study included 1845 participants, aged ≥60 years (mean age = 65 years), free of CVD at baseline, who had undergone health examinations between January 1999 and 2001, and were followed up until March 2010. Cox proportional hazard regression was performed to assess the hazard ratios (HRs) of BP categories for CVD and mortality events, considering those with optimal BP (SBP <120 mm Hg and diastolic BP [DBP] <80 mm Hg) as reference. During a median of 10 years follow-up, 380 cases of first CVD and 260 cases of mortality events occurred. In multivariable adjusted model, prehypertensive group (SBP between 120–129 mm Hg or DBP between 80–85 mm Hg) could not predict CVD (HR, 0.87 [0.61–1.24]) nor mortality events (HR, 0.86 [0.58–1.34]). Those with SBP between 140 mm Hg and 150 mm Hg (group 3) were at higher risk for developing CVD (HR, 1.79 [1.17–2.74]), but there were no significant risk for total mortality (HR, 1.13 [0.65–1.97]). Hypertensive group (SBP ≥150 mm Hg or DBP ≥90 mm Hg or taking antihypertensive drugs) was associated with increased risk of both CVD (HR, 1.73 [1.24–2.42]) and mortality events (HR, 1.49 [1.00–2.23]).However, Joint National Committee 8 suggested no more benefit with lowering SBP <150 mm Hg, but the results of this study imply that those with SBP between 150 mm Hg and 140 mm Hg are still at elevated risk for CVD/coronary heart disease events.     

Pulse pressure predicts cardiovascular risk in patients with type 2 diabetes mellitus

BACKGROUND: Pulse pressure (PP), a marker of arterial stiffness, is a better predictor of coronary heart disease (CHD) risk than systolic blood pressure (SBP) or diastolic blood pressure (DBP) in older adults. Whether this is also true in subjects with type 2 diabetes, who are at increased risk for cardiovascular disease, is unknown. METHODS: Data on 2911 type 2 diabetic subjects relating to blood pressure (BP), other risk factors, and cardiovascular events were abstracted from The Cardiff Diabetes Database. Logistic regression was used to assess the relationship among BP components and the risk of CHD, cerebrovascular (CVD), and peripheral vascular (PVD) events after correction for age, gender, cholesterol, and smoking status. RESULTS: In the 4-year follow-up period there were 574 CHD, 168 CVD, and 157 PVD events. Both PP and SBP, but not DBP, were positively associated with the risk of all event types. However, PP emerged as the best predictor of CHD events, and SBP as the best predictor of CVD and PVD events. Total and HDL-cholesterol were the most important variables associated with PP after age. CONCLUSIONS: In summary, PP is a better predictor of CHD events than SBP in persons with type 2 diabetes, but the converse is true for CVD and PVD.     

Blood pressure variables and prevalent electrocardiographic left ventricular hypertrophy in sub‐Saharan African individuals with type 2 diabetes

Background: The aim of the present study was to investigate whether brachial blood pressure (BP) variables (systolic BP [SBP], diastolic BP [DBP], pulse [PP] and mean arterial pressure [MAP]) are similar determinants of prevalent electrocardiographic left ventricular hypertrophy (LVH) in sub‐Saharan Africans with type 2 diabetes (T2D). Methods: The study included 420 individuals (49% men) with T2D who were receiving chronic care in two main referral centers in the two major cities (Douala and Yaounde) of Cameroon. Logistic regression models were used to estimate the odds ratio (OR) and 95% confidence intervals (CI) for a standard deviation (SD) higher level of SBP (25 mmHg), DBP (13), PP (18) and MAP (20) with the risk of LVH. Discrimination was assessed and compared with c‐statistics and relative integrated discrimination improvement (RIDI; %). Results: The multivariable adjusted OR (95% CI) for prevalent LVH with each SD higher pressure variable was 1.61 (1.22–2.11) for SBP, 1.27 (0.99–1.63) for DBP, 1.62 (1.23–2.15) for PP and 1.44 (1.11–1.87) for MAP. Comparison of c‐statistics revealed no difference in the discrimination power of models with each of the BP variables (P > 0.09). However, RIDI showed enhanced discrimination in the models when other BP variables were replaced with PP. However, this enhancement was marginal for SBP. Using BP combinations modestly improved discrimination. Conclusions: The best predictors of prevalent LVH in the present study population were PP and SBP, whereas DBP was the least effective predictor. These findings have implications for cardiovascular risk stratification and monitoring of risk‐reducing therapies.     

老老年人群动态血压参数与动脉僵硬度的相关性

目的探讨老老年人群动态血压参数与动脉僵硬度的相关性。方法筛选年龄≥80岁的老老年人238例,以血压≥160/95 mm Hg(1 mm Hg=0.133 kPa)为标准,分为高血压组(134例)和对照组(104例),并进行臂-踝脉搏传导速度(baPWV)和24 h动态血压监测。用Pearson分析动态血压各参数与动脉僵硬度的相关性。结果高血压组baPWV高于对照组(P<0.05)。高血压组偶测收缩压,24 h、昼间和夜间收缩压、舒张压、脉压,收缩压负荷及舒张压负荷均高于对照组.夜间收缩压下降率、舒张压下降率低于对照组,差异有统计学意义(P<0.05,P<0.01)。baPWV与偶测血压;24 h收缩压、舒张压、脉压;昼间收缩压、舒张压、脉压、心率;夜间收缩压、舒张压、脉压;收缩压负荷、舒张压负荷呈正相关(P<0.05,P<0.01),而与夜间收缩压下降率呈负相关(P<0.01)。结论高血压是老老年人群动脉僵硬度增加的一个重要因素,动脉僵硬度与动态血压、脉压、心率及血压负荷相关。     

Blood pressure indices and cardiovascular disease in the Asia Pacific region: a pooled analysis

This article aims to compare the importance of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP) as risk factors for stroke and ischemic heart disease and to assess whether the patterns are consistent by age and gender. Cox proportional-hazards regression, adjusted for cholesterol and smoking, was used to assess the associations of the 4 BP indices with stroke and ischemic heart disease by age and gender. The relative importance of individual indices was assessed with a hazard ratios for a 1-SD change in BP and by likelihood-ratio chi2 tests. The influence of >1 BP index in the Cox model was also estimated. The analyses demonstrated similar associations of SBP, DBP, and MAP with both fatal stroke and ischemic heart diseases, which were stronger than those of PP. Both SBP and MAP tended to be more important in the regression model than DBP or PP. In Cox models including DBP, addition of SBP improved the goodness of fit at all ages and for both genders. However, in Cox models including SBP, addition of DBP typically resulted in little incremental benefit over and above that of SBP alone. These data suggest that if time or resources are highly constrained, such as in much-needed epidemiologic surveys in developing countries, very little is lost from only measuring SBP.     

血压的各种指标对中老年人心脑血管病死亡事件的预测价值

目的探讨中、老年人收缩压(SBP)、舒张压(DBP)、脉压(PP)、平均动脉压(MAP)水平对远期心脑血管死亡事件预测价值的差异。方法对中老年人群10786例进行基线调查,随访8年,应用Cox回归分析4个血压指标对远期心脑血管死亡事件预测价值的差异。结果校正其他因素后,MAP和SBP分别为中、老年人最强烈的预测远期心脑血管病死亡事件危险程度的血压指标。中老年人4个血压指标每升高1个标准差(SD),其发生心脑血管病死亡危险的相对危险度(RR)由高到低分别为:(1)中年组:MAP(1.837),SBP(1.782),DBP(1.775),PP(1.750);(2)老年组:SBP(1.345),MAP(1.343),DBP(1.219),PP(1.215)。结论4个血压指标对心脑血管死亡事件的预测在不同的年龄段是不同的。中年人应着重于总体血压的控制,老年人应首先控制SBP。     

Association of increased pulse pressure with the development of heart failure in shep

The aim of this study was to assess the relationship between pulse pressure (PP) and the occurrence of heart failure (HF) in older persons with isolated systolic hypertension. Data from a prospective, multicenter, randomized, double-blind, placebo-controlled clinical trial were analyzed. A total of 4736 persons aged ≥ 60 years with systolic blood pressure (SBP) between 160 and 219 mm Hg and diastolic blood pressure (DBP) < 90 mm Hg who participated in the Systolic Hypertension in the Elderly Program (SHEP) were studied. The main outcome measures were fatal and nonfatal HF. During 4.5 years average follow-up, fatal or nonfatal HF occurred in 160 of 4736 patients. The SBP, PP, and mean arterial pressure (MAP) were strong predictors of the development of HF (P < .0002). Cox proportional hazards regression using time-dependent covariates and controlling for MAP indicated that HF was inversely related to DBP (P = 0.002) and was directly related to pulse pressure (P = 0.002). Data were similar when patients who developed myocardial infarction during follow up were excluded. These data indicate that, in older persons with isolated systolic hypertension, high pulse pressure is associated with increased risk of heart failure independently of MAP and of the occurrence of acute myocardial infarction during follow-up.     

老年高血压病患者脉压与心电图异常关系的临床探讨

目的　探讨老年高血压病患者脉压与心电图异常的关系。方法　抽样调查 6 0岁以上人群进行血压及心电图检查 ,对其中 75 0例高血压病患者进行分析 ,按平均动脉压 <113mmHg、≥ 113mmHg分为两组 ,再以脉压 <6 5mmHg、6 5～ 85mmHg、>85mmHg分为三个亚组。 结果　 (1)随着脉压增加 ,心肌肥厚 ,心电图异常均逐渐增加 ,P <0 .0 1。 (2 )总胆固醇、甘油三酯、低密度脂蛋白胆固醇并不随脉压增加而改变 ,P >0 .0 5。 (3)脉压相同而平均动脉压分别为 <113mmHg、≥ 113mmHg两组进行比较 ,心肌肥厚 ,心电图异常均无差异 ,而平均动脉压≥113mmHg组的收缩压 (SBP)、舒张压 (DBP)、平均动脉压均高于平均动脉压 <113mmHg组 ,两组差异有显著性 ,P<0 .0 1。结论　高血压病患者脉压比SBP、DBP与心电图的相关性更为密切。     

70岁以上老年心血管病患者肾功能与动态血压分析

目的研究70岁以上老年心血管病患者肾功能与动态血压的关系。方法对因为心血管疾病住院的84例老年患者（70～87岁）以简化MDRD公式估算肾小球滤过率（GFR）,以GFR〈60ml/（min.1.73m2）定为慢性肾功能不全,与同期肾功能正常者比较24h动态血压各参数的变化。结果（1）肾功能不全组（44例）平均收缩压（SBP）〉130mmHg者及冠心病、糖尿病、心力衰竭患病人数明显多于对照组;高血压及非＂杓型＂血压病例数两组比较差异无统计学意义。（2）肾功能不全组平均脉压（PP）明显高于对照组,最高舒张压（DBPmax）、舒张压波动幅度（ΔDBP）明显低于对照组。（3）患者年龄与SBP、PP、夜间SBP（nSBP）及夜间SBP负荷正相关;血清肌酐（SCr）与PP、最低SBP、nSBP正相关,与DBPmax、ΔDBP负相关,GFR呈对应改变;在控制年龄因素后,SCr与PP、nSBP相关性依然显著。结论老年心血管病患者PP增大、nSBP增高和DBPmax、ΔDBP降低与肾功能损害有关,肾功能不全患者中更多的患有冠心病、糖尿病、心力衰竭,并存在更为明显的动态血压变化。     

Morning blood pressure surge varies with age and gender in hypertensive individuals

Many studies revealed that most cardio-cerebrovascular events were closely related to morning blood pressure surge (MBPS). The aim of our study was to investigate the relationship of MBPS with age and gender in hypertensive individuals, morning blood pressures of a total of 1100 cases with primary hypertension were analyzed. In our study, the morning systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and pulse pressure (PP) of hypertensives with MBPS were all higher (P<0.01). MBPS values were correlated with age (r=0.061, P<0.05). In hypertensive individuals with MBPS, morning SBP and PP increased while morning DBP decreased (P<0.01) as patients aged. Morning DBP and MAP of female patients were lower while morning PP was higher (P<0.01). These results indicated that MBPS was associated with both age and gender in hypertensive individuals.     

Pretreatment blood pressure as a predictor of 21-year mortality

Our objective was to evaluate pretreatment predictors of longevity, particularly blood pressure, in a large cohort of hypertensive men. During 1974 to 1976, 10,367 male hypertensive veterans (47% black) were identified at screening and subsequently characterized in 32 special Veterans Administration (VA) hypertension clinics. Their mean age was 52 years and mean blood pressure (BP) 154/100 mm Hg. During an average of 21 years of follow-up, 61% died. Risk ratios for all-cause mortality as functions of BP and other risk factors are presented for each variable alone; for each variable controlling for age, race, and BP; and for a multivariate model. We observed that when the entire cohort was divided into deciles by systolic blood pressure (SBP) and by diastolic blood pressure (DBP), the risk ratios for 21-year mortality increased from lowest to highest decile by 178% for SBP and 16% for DBP. When the deciles were computed separately by age group, increases from lowest to highest decile for those less than 40 years of age were 138% for SBP and 263% for DBP. For those over 60 years, the increases were 154% and −10%, respectively. Although blacks were younger and had more severe diastolic hypertension than whites, the risk ratios were similar within each race group. Risk patterns for mean arterial pressure and pulse pressure resembled those for SBP but had smaller gradients. Survival curves for BP groups suggested constant mortality rates during follow-up. Other significant observations included decreasing mortality with increasing body mass index and increased mortality in the Stroke Belt. We concluded that pretreatment SBP strongly predicted all-cause mortality during 21-year follow-up. For the young, both SBP and DBP were strong predictors; for the elderly, only SBP was predictive.     

Quantitative study of circadian variations of ambulatory blood pressure in Chinese healthy, hypertensive, and diabetes subjects

Ambulatory blood pressure monitoring (ABPM) recorded abundant data of BP and heart rate (HR) variations with even more derived parameters for evaluation of BP. Using our ABP database system established recently, we studied quantitatively the data of 24-hr ABP in Chinese. First, 155 Chinese were divided into three groups: 50 healthy subjects (C) of 20 men and 30 women, aged 60.0 +/- 10.3 (SD) years; 58 hypertensive patients (H, mild or moderate hypertension) of 33 men and 25 women, aged 59.4 +/- 8.0 years; 47 diabetes patients (D, type 2 diabetes, all were normotensive and with no insulin treatment) with 28 men and 19 women, aged 61.0 +/- 8.5 years. Then 24-hr ABP was monitored by TM-2421 Monitor and data were analyzed by ABP database, cosinor method, and conventional statistics. Our results were 4-fold: 1) systolic BP (SBP), diastolic BP (DBP), HR, rate-pressure product (HR x SBP) showed circadian variations, and significant circadian rhythms were confirmed by cosinor method in all groups. MESOR (midline estimate statistic of rhythm) differed significantly among three groups (H had the highest and C had the lowest values); 2) BP means (SBP, DBP, pulse pressure [PP], and HR x SBP) and BP loads (SBP, DBP, and PP) showed significant differences among the groups (H and D had higher values than that of C); 3) there were no significant differences of BP variability (BPV) of SBP, DBP, and PP among the groups; 4) areas under curve of BP (SBP, DBP, and PP) in H were significantly higher than in C and there was no significant difference between H and D. We concluded that ABPM can offer abundant information on BP evaluation by its direct recording data and derived parameters. The computerized way of treating the large numbers of ABPM values supplies a useful tool in evaluation of BP. Our results suggest that clinically normotensive diabetes patients had some pathological alterations in their BP systems.