Systolic and diastolic blood pressures as predictors of coronary heart disease mortality in the Whitehall study

Migrant status disparities in blood pressure: a multiple mediation analysis of modifiable factors

BACKGROUND

We examined differences in blood pressure (BP) levels between first-generation immigrants and natives in adult residents in Northeast Italy, and investigated the role of lifestyle behaviors, body mass index (BMI), and education as potentially modifiable mediating factors.

METHODS

We included 20-69-year-old participants from the Health Surveillance Program of the Veneto Region (n = 37,710). Immigrants born in a high migratory pressure country (HMPC) were further grouped into geographical macro-areas. The outcomes were systolic BP (SBP) and hypertension. Multiple mediation analyses were performed to determine the contribution of each mediator of the SBP/migrant status association.

RESULTS

Of the 37,380 subjects included, 8.7% were born in an HMPC. BMI, education, alcohol, sweets and meat consumption were included as potential mediators. A small advantage in SBP was seen for immigrants compared to natives (β =  - 0.71,95%CI  - 1.30;  - 0.10). The direct effect (net of the covariates) of immigrant status on SBP was a reduction of 1.62 mmHg (95%CI  - 2.25;  - 0.98). BMI played the highest suppressive role (β = 1.14,95%CI 0.99; 1.35), followed by education. Alcohol consumption amplified the health advantage of immigrants. The suppressing effect of BMI was particularly evident among women and North Africans compared to natives. Similar results were seen for hypertension rates.

CONCLUSIONS

Although causation cannot be proven given the cross-sectional design, our findings identify BMI as the most effective target to preserve the health advantage of immigrants with respect to BP levels.

Associations Between Objective Sleep and Ambulatory Blood Pressure in a Community Sample

OBJECTIVE

Epidemiologic data increasingly support sleep as a determinant of cardiovascular disease risk. Fewer studies have investigated the mechanisms underlying this relationship using objective sleep assessment approaches. Therefore, the aim of this study was to examine associations between daily blood pressure (BP) and both objectively assessed sleep duration and efficiency.

METHODS

A diverse community sample of 300 men and women aged 21 to 70 years, enrolled in the North Texas Heart Study, participated in the study. Actigraphy-assessed sleep was monitored for two consecutive nights with ambulatory BP sampled randomly within 45-minute blocks on the first and second day as well as the second night.

RESULTS

Overall, sleep duration results paralleled those of sleep efficiency. Individuals with lower sleep efficiency had higher daytime systolic (B = -0.35, SE = 0.11, p = .0018, R = 0.26) but not diastolic BP (B = -0.043, SE = 0.068, p = .52, R = 0.17) and higher nighttime BP (systolic: B = -0.37, SE = 0.10, p < .001, R = .15; diastolic: B = -0.20, SE = 0.059, p < .001, R = .14). Moreover, lower sleep efficiency on one night was associated with higher systolic (B = -0.51, SE = 0.11, p < .001, R = 0.23) and diastolic BP (B = -0.17, SE = 0.065, p = .012, R = .16) the following day. When 'asleep' BP was taken into account instead of nighttime BP, the associations between sleep and BP disappeared. When both sleep duration and efficiency were assessed together, sleep efficiency was associated with daytime systolic BP, whereas sleep duration was associated with nighttime BP.

CONCLUSIONS

Lower sleep duration and efficiency are associated with higher daytime systolic BP and higher nighttime BP when assessed separately. When assessed together, sleep duration and efficiency diverge in their associations with BP at different times of day. These results warrant further investigation of these possible pathways to disease.

Association between antenatal blood pressure and 5-year postpartum retinal arteriolar structural and functional changes

Objective

Studies have shown that hypertensive disorders of pregnancy (HDP) are associated with both postpartum retinal microvascular changes and cardiovascular (CV) risks. However, the underlying mechanism of HDP transitioning to microvascular and macrovascular changes remains unknown, due to the interaction between microvasculature and CV risks. In this study, we examined whether associations between antenatal systolic blood pressure (SBP) and postpartum retinal arteriolar changes are independent of postpartum CV risks.

Methods

We included 276 Singaporean mothers attending both baseline index pregnancy (2009–2010) and 5-year postpartum follow-up visits (2014–2015). We measured SBP at baseline. At follow-up, we assessed retinal microvascular structure and function with retinal photography and dynamic vessel analyser, together with CV risks using a validated 2008 Framingham Risk Score (FRS). We performed a traditional four-step mediation analysis using linear regression by adjusting for a series of baseline characteristics: age, ethnicity, college degree, prepregnancy body mass index and gestational diabetes mellitus diagnosis at baseline.

Results

We found that each 10 mm Hg increase in baseline SBP was associated with reduced arteriolar calibre (−1.3 µm; 95% CI −3.0 to 0.2) and fractal dimension (−0.4 degrees of freedom (df); −1.0 to 0.2), and significantly with increased arteriolar constriction (0.5%; 0.001 to 1.0) at 5-year postpartum. Even though baseline SBP was associated with postpartum FRS, the latter was not associated with any retinal arteriolar measures. Therefore, no further mediation analysis was required.

Conclusion

Our study suggested that elevated SBP during pregnancy was associated with suboptimal retinal arteriolar structure and function independent of postpartum CV risks.

Salusin-α levels are negatively correlated with diastolic blood pressure in children with obesity

Salusins have emerged as a new biomarker that reflects an increased inflammatory state, which is associated with cardiovascular risk. We investigated the predictive value and usefulness of salusins as an inflammatory biomarker in obese children. This prospective cohort study included 75 obese children and 101 healthy children (as a control group). Salusin-α, Salusin-β, and various cardiovascular parameters were assessed in both groups. Correlation analyses of Salusin-α and Salusin-β with body mass index standard deviation scores and inflammatory and cardiovascular markers were performed. The mean patient age was 11.9±2.4 years for the obese group and 12.5±2.1 years for the control group. The obese children had a significantly higher heart rate, systolic blood pressure, diastolic blood pressure, epicardial adipose tissue thickness, and left ventricular mass than did the children in the control group. There was no significant correlation between Salusin-α and Salusin-β and body mass index; however, there was a negative correlation between Salusin- α and diastolic blood pressure (r = 0.277, p = 0.004). Overall, there was no significant difference in the Salusin-α and Salusin-β levels between obese and healthy children. However, a negative correlation was found between Salusin-α and diastolic blood pressure. Although this result suggests that Salusin-α might be an early marker of cardiovascular involvement in obese children, further studies are needed to demonstrate the predictive value of salusins.

A comparison of blood pressure in community pharmacies with ambulatory, home and general practitioner office readings: systematic review and meta-analysis

BACKGROUND

Blood pressure (BP) readings are traditionally taken in a clinic setting, with treatment recommendations based on these measurements. The clinical interpretation of BP readings taken in community pharmacies is currently unclear. This study aimed to systematically review all literature comparing community pharmacy BP (CPBP) readings with ambulatory BP monitoring (ABPM), home BP monitoring and general practitioner clinic readings.

METHOD

Studies were included if they compared CPBP with at least one other measurement modality used for the diagnosis or management of hypertension. Mean CPBP readings were compared with other measurement modalities and summarized using random-effects meta-analyses. The primary outcome was to compare CPBP with gold standard ABPM readings.

RESULTS

Searches generated 3815 studies of which eight were included in the meta-analyses. The mean systolic CPBP-daytime ABPM difference was small [+1.6 mmHg (95% confidence interval -1.2 to 4.3) three studies, n = 319]. CPBP was significantly higher than 24-h ABPM [+7.8 mmHg (95% confidence interval 1.5-14.1) three studies n = 429]. Comparisons with general practitioner clinic readings (six studies, n = 2100) were inconclusive with significant heterogeneity between studies. CPBP and home BP monitoring readings (five studies, n = 1848) were nonsignificantly different. Diastolic comparisons mirrored systolic comparisons in all but the CPBP-daytime ABPM comparison, where CPBP was significantly higher.

CONCLUSION

Current evidence around the clinical interpretation of CPBP is inconclusive. Although this review suggests that adopting the 135/85 mmHg threshold for hypertension might be reasonable and potentially result in a higher sensitivity for detecting patients with truly raised BP in pharmacies, the impact of this lower threshold on increased referrals to general practice clinics must be considered.

Hypertension and mortality in the Golestan Cohort Study: A prospective study of 50 000 adults in Iran

High blood pressure has been the second most important determinant of disease burden in Iran since the 1990s. Despite well-recognized evidence on the association of high blood pressure and mortality in other countries, this relationship has not been fully investigated in the demographic setting of Iran. The current study is the first large-scale longitudinal study of this association in Iran. Briefly, 50 045 subjects between 40 and 75 years of age have been recruited and followed. Blood pressure measurements were carried out at baseline. Causes of death were reported and verified by verbal autopsy throughout the follow-up period. The outcomes of interest were all-cause deaths and deaths due to ischemic heart disease (IHD) or stroke. Cox proportional hazards regression models were used to estimate hazard ratios (HRs). A total of 46 674 subjects free from cardiovascular disease at baseline were analyzed. Absolute mortality rates increased along with increasing systolic or diastolic blood pressure above 120 and 80 mm Hg, respectively. Adjusted HRs (95% confidence intervals) for each 20 mm Hg increase in systolic blood pressure in all age groups were 1.18 (1.13-1.23) for all-cause mortality, 1.21 (1.13-1.31) for deaths due to IHD and 1.50 (1.39-1.63) for deaths due to stroke. Unadjusted and adjusted HRs were higher in younger subjects and decreased with increasing age of the participants. High blood pressure is a serious threat to the health of Iranians. The entire health-care system of Iran should be involved in a comprehensive action plan for controlling blood pressure.

Blood pressure trajectories in early adulthood and subclinical atherosclerosis in middle age

IMPORTANCE

Single measures of blood pressure (BP) levels are associated with the development of atherosclerosis; however, long-term patterns in BP and their effect on cardiovascular disease risk are poorly characterized.

OBJECTIVES

To identify common BP trajectories throughout early adulthood and to determine their association with presence of coronary artery calcification (CAC) during middle age.

DESIGN, SETTING, AND PARTICIPANTS

Prospective cohort data from 4681 participants in the CARDIA study, who were black and white men and women aged 18 to 30 years at baseline in 1985-1986 at 4 urban US sites, collected through 25 years of follow-up (2010-2011). We examined systolic BP, diastolic BP, and mid-BP (calculated as [SBP+DBP]/2, an important marker of coronary heart disease risk among younger populations) at baseline and years 2, 5, 7, 10, 15, 20, and 25. Latent mixture modeling was used to identify trajectories in systolic, diastolic, and mid-BP over time.

MAIN OUTCOMES AND MEASURES

Coronary artery calcification greater than or equal to Agatston score of 100 Hounsfield units (HU) at year 25.

RESULTS

We identified 5 distinct mid-BP trajectories: low-stable (21.8%; 95% CI, 19.9%-23.7%; n=987), moderate-stable (42.3%; 40.3%-44.3%; n=2085), moderate-increasing (12.2%; 10.4%-14.0%; n=489), elevated-stable (19.0%; 17.1%-20.0%; n=903), and elevated-increasing (4.8%; 4.0%-5.5%; n=217). Compared with the low-stable group, trajectories with elevated BP levels had greater odds of having a CAC score of 100 HU or greater. Adjusted odds ratios were 1.44 (95% CI, 0.83-2.49) for moderate-stable, 1.86 (95% CI, 0.91-3.82) for moderate-increasing, 2.28 (95% CI, 1.24-4.18), for elevated-stable, and 3.70 (95% CI, 1.66-8.20) for elevated-increasing groups. The adjusted prevalence of a CAC score of 100 HU or higher was 5.8% in the low-stable group. These odds ratios represent an absolute increase of 2.7%, 5%, 6.3%, and 12.9% for the prevalence of a CAC score of 100 HU or higher for the moderate-stable, moderate-increasing, elevated-stable and elevated-increasing groups, respectively, compared with the low-stable group. Associations were not altered after adjustment for baseline and year 25 BP. Findings were similar for trajectories of isolated systolic BP trajectories but were attenuated for diastolic BP trajectories.

CONCLUSIONS AND RELEVANCE

Blood pressure trajectories throughout young adulthood vary, and higher BP trajectories were associated with an increased risk of CAC in middle age. Long-term trajectories in BP may assist in more accurate identification of individuals with subclinical atherosclerosis.

Gender difference and economic gradients in the secular trend of population systolic blood pressure

To a large extent population blood pressure (PBP) affects morbidity and mortality in the society. Reports indicated that PBP decreased in many western countries. The associations between the main cardiovascular risk factors and the changing PBP have been described. The aim of this study was to investigate association between income factors and trends in population BP and hypertension. Copenhagen City Heart Study is a prospective longitudinal epidemiological study on almost 20000 individuals through four surveys from 1976 to 2003. The BP measurement was fully standardised. Questionnaires on household income and CV risk factors were completed by the participants. After adjustment for cardiovascular risk factors there were no significant differences in systolic BP (SBP) trend associated to income among men. Among women, however, there was a reverse relationship between SBP and income. In addition, there was a trend towards a lowering of risk-factor adjusted SBP in the high income women with time. The mechanism that lies behind the associations between trend in SBP and income is not known but data suggest that poor lifestyle may explain some of the differences. The treated hypertensives are treated without income associated treatment differences.

IN CONCLUSION

Women in higher income groups have lower SBP than women in low-income groups and the gap between SBP in high-income women and low-income women increased with time. There were no significant differences in SBP-trend associated to income among men. Results in treating hypertension did not differ between the income groups.

The TRINITY Study: distribution of systolic blood pressure reductions

Background

Elevated systolic blood pressure is more difficult to control than elevated diastolic blood pressure. The objective of this prespecified analysis of the Triple Therapy with Olmesartan Medoxomil, Amlodipine, and Hydrochlorothiazide in Hypertensive Patients Study (TRINITY) was to compare the efficacy of olmesartan medoxomil (OM) 40 mg, amlodipine besylate (AML) 10 mg, and hydrochlorothiazide (HCTZ) 25 mg triple-combination treatment with the component dual-combination treatments in reducing elevated seated systolic blood pressure (SeSBP).

Methods

The 12-week TRINITY study randomized participants to either one of the three component dual-combination treatments (OM 40 mg/AML 10 mg, OM 40 mg/HCTZ 25 mg, or AML 10 mg/HCTZ 25 mg) or the triple-combination treatment. The primary outcome of this analysis was the categorical distribution of SeSBP reductions at week 12 from baseline with OM 40 mg/AML 10 mg/HCTZ 25 mg versus the dual-combination treatments.

Results

SeSBP reductions >50 mmHg were seen in 24.4% of participants receiving triple-combination treatment versus 8.1%–15.8% receiving dual-combination treatment. More participants receiving triple-combination treatment achieved the SeSBP target of <140 mmHg (73.6% versus 51.3%–58.8%; P < 0.001) and the seated blood pressure target of <140/90 mmHg (69.9% versus 41.1%–53.4%; P < 0.001). Prevalence and severity of adverse events were similar in all treatment groups.

Conclusion

Treatment with OM 40 mg/AML 10 mg/HCTZ 25 mg was well tolerated and more effective in reducing SeSBP than the dual-combination treatments.

Stress and Its Effects on Glucose Metabolism and 11β-HSD Activities in Rats Fed on a Combination of High-Fat and High-Sucrose Diet with Glycyrrhizic Acid

Chronic stress has been shown to have a strong link towards metabolic syndrome (MetS). Glycyrrhizic acid (GA) meanwhile has been shown to improve MetS symptoms caused by an unhealthy diet by inhibiting 11 β -HSD 1. This experiment aimed to determine the effects of continuous, moderate-intensity stress on rats with and without GA intake on systolic blood pressure (SBP) across a 28-day period, as well as glucose metabolism, and 11 β -HSD 1 and 2 activities at the end of the 28-day period. Adaptation to the stressor (as shown by SBP) resulted in no significant defects in glucose metabolism by the end of the experimental duration. However, a weakly significant increase in renal 11 β -HSD 1 and a significant increase in subcutaneous adipose tissue 11 β -HSD 1 activities were observed. GA intake did not elicit any significant benefit in glucose metabolism, indicating that the stress response may block its effects. However, GA-induced improvements in 11 β -HSD activities in certain tissues were observed, although it is uncertain if these effects are manifested after adaptation due to the withdrawal of the stress response. Hence the ability of GA to improve stress-induced disturbances in the absence of adaptation needs to be investigated further.

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.

Blood pressure in early adulthood, hypertension in middle age, and future cardiovascular disease mortality: HAHS (Harvard Alumni Health Study)

OBJECTIVES

We sought to examine the association of early adulthood blood pressure with cardiovascular disease (CVD) mortality, while accounting for middle-age hypertension.

BACKGROUND

Elevated blood pressure in middle age is an established CVD risk factor, but evidence for association with measurements earlier in life is sparse.

METHODS

The HAHS (Harvard Alumni Health Study) is a cohort study of 18,881 male university students who had their blood pressure measured at university entry (1914 to 1952; mean age 18.3 years) and who responded to a questionnaire mailed in either 1962 or 1966 (mean age 45.8 years) in which physician-diagnosed hypertension status was reported. Study members were subsequently followed for mortality until the end of 1998.

RESULTS

Following adjustment for age, body mass index, smoking, and physical activity at college entry, compared with men who were normotensive according to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure criteria (<120/<80 mm Hg), there was an elevated risk of coronary heart disease (CHD) mortality (1,917 deaths) in those who were pre-hypertensive (120 to 139/80 to 89 mm Hg) (hazard ratio [HR]: 1.21; 95% confidence interval [CI]: 1.07 to 1.36), stage 1 (140 to 159/90 to 99 mm Hg) (HR: 1.46; 95% CI: 1.25 to 1.70), and stage 2 hypertensive (≥160/≥100 mm Hg) (HR: 1.89; 95% CI: 1.46 to 2.45), incremental across categories (p(trend) < 0.001). After additionally accounting for middle-age hypertension, estimates were somewhat attenuated, but the pattern remained. Similar associations were apparent for total and CVD mortality, but not stroke mortality.

CONCLUSIONS

Higher blood pressure in early adulthood was associated with elevated risk of all-cause mortality, CVD, and CHD, but not stroke, several decades later. Effects largely persisted after taking into account mediation by middle-age hypertension. Thus, the long-term benefits of blood pressure lowering in early adulthood are promising, but supporting trial data are required.

Diabetic cardiomyopathy: from the pathophysiology of the cardiac myocytes to current diagnosis and management strategies

Diabetic cardiomyopathy (DCM), although a distinct clinical entity, is also a part of the diabetic atherosclerosis process. It may be independent of the coexistence of ischemic heart disease, hypertension, or other macrovascular complications. Its pathological substrate is characterized by the presence of myocardial damage, reactive hypertrophy, and intermediary fibrosis, structural and functional changes of the small coronary vessels, disturbance of the management of the metabolic cardiovascular load, and cardiac autonomic neuropathy. These alterations make the diabetic heart susceptible to ischemia and less able to recover from an ischemic attack. Arterial hypertension frequently coexists with and exacerbates cardiac functioning, leading to the premature appearance of heart failure. Classical and newer echocardiographic methods are available for early diagnosis. Currently, there is no specific treatment for DCM; targeting its pathophysiological substrate by effective risk management protects the myocardium from further damage and has a recognized primary role in its prevention. Its pathophysiological substrate is also the objective for the new therapies and alternative remedies.

Influence of blood pressure and blood pressure change on the risk of congestive heart failure in the elderly

BACKGROUND

While elevated blood pressure (BP) has been consistently associated with incident congestive heart failure (CHF), much less is known about the effect of BP change. We therefore assessed the association of BP change over time with subsequent risk of CHF.

METHODS

4655 participants >/=65 years old from the prospective Established Populations for Epidemiologic Studies of the Elderly program who were alive and free of CHF after six years of follow-up were included. Categories of sustained high BP, sustained low BP, BP progression and BP regression were defined according to BP differences between study entry and six years of follow-up. The primary endpoint was incident CHF subsequent to the six year examination.

RESULTS

During 4.3 years of follow-up after the six year examination, 642 events occurred. The hazard ratio (HR) (95% confidence interval (CI)) for systolic BP > or =160 compared to <120 mm Hg at six years was 1.39 (1.04-1.86). Conversely, the lowest diastolic BP category at six years was associated with an increased risk of incident CHF (HR (95% CI) <70 mm Hg versus 70-79 mm Hg 1.42 (1.18-1.71)). Systolic and diastolic BP were better predictors than pulse pressure. The HRs (95% CI) for incident CHF associated with sustained high systolic BP > or =160 mm Hg and systolic BP progression were 1.35 (0.97-1.89) and 1.45 (1.14-1.85), respectively. Conversely, significant associations were found in those with sustained low diastolic BP or diastolic BP regression (HR (95% CI) 1.42 (1.11-1.83) and 1.45 (1.19-1.76), respectively).

CONCLUSION

While persistently elevated systolic BP and systolic BP progression were strong predictors of CHF in the elderly, inverse associations were found with regard to diastolic BP. Systolic and diastolic BP were better predictors of CHF than pulse pressure.

Influence of systolic and diastolic blood pressure on the risk of incident atrial fibrillation in women

BACKGROUND

The influence of systolic and diastolic blood pressure (BP) on incident atrial fibrillation (AF) is not well studied among initially healthy, middle-aged women.

METHODS AND RESULTS

A total of 34,221 women participating in the Women's Health Study were prospectively followed up for incident AF. The risk of AF across categories of systolic and diastolic BP was compared by use of Cox proportional-hazards models. During 12.4 years of follow-up, 644 incident AF events occurred. Using BP measurements at baseline, we discovered that the long-term risk of AF was significantly increased across categories of systolic and diastolic BP. Multivariable-adjusted hazard ratios for systolic BP categories (<120, 120 to 129, 130 to 139, 140 to 159, and > or =160 mm Hg) were 1.0, 1.00 (95% CI, 0.78 to 1.28), 1.28 (95% CI, 1.00 to 1.63), 1.56 (95% CI, 1.22 to 2.01), and 2.74 (95% CI, 1.77 to 4.22) (P for trend <0.0001). Adjusted hazard ratios across baseline diastolic BP categories (<65, 65 to 74, 75 to 84, 85 to 89, 90 to 94, and > or =95 mm Hg) were 1.0, 1.17 (95% CI, 0.81 to 1.69), 1.18 (95% CI, 0.84 to 1.65), 1.53 (95% CI, 1.05 to 2.23), 1.35 (95% CI, 0.82 to 2.22), and 2.15 (95% CI, 1.21 to 3.84) (P for trend=0.004). When BP changes over time were accounted for in updated models, multivariable-adjusted hazard ratios were 1.0, 1.14 (95% CI, 0.89 to 1.46), 1.37 (95% CI, 1.07 to 1.76), 1.71 (95% CI, 1.33 to 2.21), and 2.21 (95% CI, 1.45 to 3.36) (P for trend <0.0001) for systolic BP categories and 1.0, 1.12 (95% CI, 0.82 to 1.52), 1.13 (95% CI, 0.83 to 1.52), 1.30 (95% CI, 0.89 to 1.88), 1.50 (95% CI, 1.01 to 1.88), and 1.54 (95% CI, 0.75 to 3.14) (P for trend=0.026) for diastolic BP categories.

CONCLUSIONS

In this large cohort of initially healthy women, BP was strongly associated with incident AF, and systolic BP was a better predictor than diastolic BP. Systolic BP levels within the nonhypertensive range were independently associated with incident AF even after BP changes over time were taken into account.

Altered blood pressure progression in the community and its relation to clinical events

BACKGROUND

Long-term blood pressure (BP) progression and its importance as a predictor of clinical outcome have not been well characterized across different periods.

METHODS

We evaluated period trends for 3 BP variables (long-term slope and mean BP during a baseline period of 16 years, and last baseline value) in an earlier period (1953-1971; n = 1644, mean participant age, 61 years) and in a later period (1971-1990; n = 1040, mean participant age, 58 years) in participants in the Framingham Heart Study who initially did not have hypertension. In addition, we explored the relation of BP to cardiovascular disease incidence and all-cause mortality in the 2 periods, each with up to 16 years of follow-up.

RESULTS

Long-term slope, mean, and last baseline BP measurements were significantly lower in the later period (P < .001). Rates of hypertension control (BP <140/90 mm Hg) were higher in the later vs the earlier period (32% vs 23%; P < .001). Multivariate hazard ratios for the relation of BP to outcomes were generally lower in the later period; this was statistically significant for the relation of last baseline BP to all-cause mortality (hazard ratio for 1-SD increase in systolic BP, 1.02 vs 1.25, P = .03; hazard ratio for diastolic BP, 1.00 vs 1.23, P = .04).

CONCLUSIONS

We found evidence that BP levels in the community have changed over time, coinciding with improved rates of hypertension control and attenuation of BP-mortality relations. These findings are consistent with the hypothesis that hypertension treatment in the community has altered the natural history of BP progression and its relation to clinical outcome.

Exercise blood pressure and the risk of incident cardiovascular disease (from the Framingham Heart Study)

Exaggerated systolic blood pressure (BP) augmentation with exercise has been associated with impaired endothelial function and cardiovascular risk. However, previous studies were largely restricted to men, did not evaluate diastolic BP, and focused on peak exercise measures, which are influenced by effort and fitness level. The aim of this study was to determine the association of exercise BP responses with risk of incident cardiovascular disease (CVD). BP was assessed during stage 2 of the Bruce protocol and during recovery in 3,045 Framingham Study subjects (mean age 43 years; 53% women). The association between exercise BP and CVD events during 20 years of follow-up was examined using Cox proportional hazards models. In age- and sex-adjusted analyses, exercise systolic and diastolic BP were associated with incident CVD (adjusted hazard ratios [HRs] for top quintile 1.55, 95% confidence interval [CI] 1.18 to 2.04; and 1.77, 95% CI 1.35 to 2.31, respectively, relative to the lower 4 quintiles; p <0.005). After adjustment for BP at rest and conventional risk factors, exercise diastolic BP (HR 1.41, 95% CI 1.01 to 1.95, p = 0.04), but not exercise systolic BP (HR 0.97, 95% CI 0.68 to 1.38, p = 0.86), remained a significant predictor of CVD. Similarly, in recovery responses after exercise, only diastolic BP (HR 1.53, 95% CI 1.08 to 2.18, p = 0.02) predicted incident CVD in multivariable models. In conclusion, in middle-aged adults, diastolic BP during low-intensity exercise and recovery predicted incident CVD. Our findings support the concept that dynamic BP provides incremental information to BP at rest and suggest that exercise diastolic BP may be a better predictor than exercise systolic BP in this age group.

Treatment of systolic hypertension: spotlight on recent studies with angiotensin II antagonists

Systolic blood pressure has a continuous, graded, strong, independent, and aetiologically significant relationship to mortality from coronary heart disease, stroke, and all cardiovascular diseases, as well as to all-cause mortality and life expectancy. Angiotensin II (AII) may be intimately involved in the pathogenesis of systolic hypertension through multiple mechanisms, including decreasing the elastin content and increasing the collagen content of the arterial wall, thickening and fibrotic remodelling of the vascular intima, and proliferating smooth muscle cells in the arterial wall, resulting in increased thickness, stiffening, and partial loss of contractility. AII antagonists may therefore offer hitherto unrecognized benefits (independent of blood pressure) on age-related vascular damage and provide particular benefits in patients with systolic hypertension. Recent evidence has demonstrated that losartan offers cardiovascular outcomes benefits in isolated systolic hypertension (ISH) associated with an excellent tolerability profile. This, in patients with ISH, AII antagonists more facilitate systolic BP control, providing cardiovascular protection and offering an excellent risk-benefit profile.

Epidemiological, pathophysiological and clinical significance of systolic, diastolic and pulse pressure

Long-term population surveys and studies of untreated hypertensive patients both strongly suggest that over the age of about 45, the height of the systolic blood pressure is a better predictor of cardiovascular outcome than the diastolic pressure. Research into echocardiographic left ventricular size, endothelial function and thromborheology also back up this supposition. In clinical practice, the treatment of isolated systolic hypertension has been shown to be very worthwhile. There remains some uncertainty as to the relative significance of diastolic blood pressure when it is frankly high, as in severe systo-diastolic hypertension. However some clinicians and epidemiologists have questioned whether diastolic pressure is still worth measuring, given the overwhelming importance of the height of the systolic blood pressure at predicting outcome.

Blood pressure and site-specific cancer mortality: evidence from the original Whitehall study

Studies relating blood pressure to cancer risk have some shortcomings and have revealed inconsistent findings. In 17 498 middle-aged London-based government employees we related systolic and diastolic blood pressure recorded at baseline examination (1967–1970) to the risk of cancer mortality risk at 13 anatomical sites 25 years later. Following adjustment for potential confounding and mediating factors, inverse associations between blood pressure and mortality due to leukaemia and cancer of the pancreas (diastolic only) were seen. Blood pressure was also positively related to cancer of the liver and rectum (diastolic only). The statistically significant blood pressure–cancer associations seen in this large-scale prospective investigation offering high power were scarce and of sufficiently small magnitude as to be attributable to chance or confounding.

Epidemiologic appraisal of hypertension as a coronary risk factor in the elderly

Five decades of epidemiologic research has established elevated blood pressure as a major contributor to atherosclerotic cardiovascular diseases in the elderly, including coronary heart disease. Clinicians formerly favored the diagnosis and treatment of hypertension in terms of the diastolic blood pressure and categorical "hypertension." Epidemiologic data now emphasize the essential role of systolic blood pressure, pulse pressure, and a graded influence of blood pressure, even within the high-normal range. The risk of coronary heart disease, the most common lethal sequela of hypertension, increases with the extent of risk factor clustering. Among hypertensive persons, about 39% of coronary events in men and 68% in women are attributable to the presence of two or more additional risk factors. When risk factor clustering is associated with glucose intolerance, obesity, and dyslipidemia, it may be attributed to insulin resistance promoted by abdominal obesity. Other hazardous influences often accompanying hypertension in the elderly are the presence of an elevated heart rate, elevated levels of fibrinogen, and left ventricular hypertrophy. Because clustering with other risk factors is characteristic of hypertension in the elderly, it is essential to screen for them and for the presence of comorbid cardiovascular diseases, target organ disease, and subclinical vascular disease likely to be present. Multivariate risk assessment profiles enable global estimation of hypertensive risk of developing coronary heart disease. Hypertensive elderly patients are more appropriately targeted for antihypertensive therapy by such risk stratification than by relying solely on the severity of the blood pressure elevation. The goal of therapy should be to improve the multivariate risk profile as well as the level of the blood pressure.

Baseline abnormalities of endothelial function and thrombogenesis in relation to prognosis in essential hypertension

The present study was designed to test the hypothesis that markers of a hypercoagulable state predict subsequent cardiovascular events in hypertensives. To do this, we performed a prospective follow-up analysis of 178 patients (86 male; mean age, 54 years (standard deviation, 15); mean blood pressure, 188/103 mmHg) recruited from a hypertension clinic in a city-centre teaching hospital serving a multi-ethnic population. The main outcome measures were clinical and echocardiographic details, and laboratory markers of thrombosis and haemostasis (fibrinogen, fibrin D-dimer, plasminogen activator inhibitor, soluble P-selectin, von Willebrand factor, and viscosity) that were measured at baseline. After a mean follow-up of 45 months (interquartile range, 37-54), 30 subjects experienced one of a number of endpoints that included death or adverse cardiovascular event. These patients were older (P<0.001) and had significantly higher plasma von Willebrand factor (P=0.015) and fibrin D-dimer levels (P=0.005) compared with those 148 who were free of endpoints at follow-up. There were no statistically significant differences in mean blood pressure, other measured parameters, and the left ventricular mass index between the groups. Using univariate 'time to event' analysis, only high (> or = median) baseline systolic blood pressures were associated with a shortened event-free survival (log rank test, P= 0.0078). We conclude that hypertensive patients who experienced a new cardiovascular event were much older and had more endothelial dysfunction and thrombogenesis than those who were free of complications. However, only high baseline systolic blood pressures were associated with a shortened event-free survival.

Blood pressure and mortality risk in older people: comparison between African Americans and whites

OBJECTIVES

To determine the risk from hypertension for all-cause mortality in a racially mixed sample of community-dwelling older adults.

DESIGN

Baseline blood pressure was assessed between 1985 and 1986 in a sample of persons 65 years of age and older from five counties of the Piedmont of North Carolina (N = 4,162). All-cause mortality was monitored annually over the subsequent 6 years as part of the Established Populations for Epidemiologic Studies of the Elderly (EPESE) sponsored by the National Institute on Aging.

SETTING

Eighteen percent of all respondents in the sample had a systolic blood pressure of > 160 (17% for whites and 18% for African Americans) and 16% had a diastolic blood pressure of >90 (14% for whites and 20% for African Americans). During the 6 years of follow-up, 29% of the sample died (with no difference in mortality rates between whites and African Americans).

PARTICIPANTS

4,000 community-dwelling people age 65 years and older; 1,846 were white and 2,154 were African American.

MEASUREMENTS

Systolic and diastolic blood pressure and all-cause mortality.

RESULTS

Systolic blood pressure positively related to mortality during the 6 years of follow-up (relative risk = 1.05). Among whites the relationship of diastolic pressure to mortality was nonlinear, with those at the upper and lower ends of the distribution at increased risk. Among African Americans, diastolic pressure was unrelated to mortality. The analyses were controlled for age; gender; education; body mass index (BMI); smoking history; taking a medication to manage blood pressure; a history of cancer, diabetes mellitus, heart attack, or stroke; poor subjective health; impaired functional status; and cognitive impairment.

CONCLUSIONS

The findings confirm that among older adults there is a significant relationship overall between systolic blood pressure and mortality over 6 years of follow-up in both whites and African Americans. Diastolic pressure was a risk factor for whites only.

Does the relation of blood pressure to coronary heart disease risk change with aging? The Framingham Heart Study

BACKGROUND

We examined the relative importance of diastolic (DBP), systolic (SBP) and pulse pressure (PP) as predictors of coronary heart disease (CHD) risk in different age groups of Framingham Heart Study participants.

METHODS AND RESULTS

We studied 3060 men and 3479 women between 20 and 79 years of age who were free of CHD and were not on antihypertensive drug therapy at baseline. Cox regression adjusted for age, sex, and other risk factors was used to assess the relations of BP indexes to CHD risk over a 20-year follow-up. In the group <50 years of age, DBP was the strongest predictor of CHD risk (hazard ratio [HR] per 10 mm Hg increment, 1.34; 95% CI, 1.18 to 1.51) rather than SBP (HR, 1.14; 95% CI, 1.06 to 1.24) or PP (HR, 1.02; 95% CI, 0.89 to 1.17). In the group 50 to 59 years of age, risks were comparable for all 3 BP indexes. In the older age group, the strongest predictor of CHD risk was PP (HR, 1.24; 95% CI, 1.16 to 1.33). When both SBP and DBP were considered jointly, the former was directly and the latter was inversely related to CHD risk in the oldest age group

CONCLUSIONS

With increasing age, there was a gradual shift from DBP to SBP and then to PP as predictors of CHD risk. In patients <50 years of age, DBP was the strongest predictor. Age 50 to 59 years was a transition period when all 3 BP indexes were comparable predictors, and from 60 years of age on, DBP was negatively related to CHD risk so that PP became superior to SBP.

Assessment of aortic line of elasticity using polynomial regression analysis

BACKGROUND

The aim of this study was to assess the sigmoid line of elasticity in the human aorta.

METHODS AND RESULTS

The pressure-diameter relation was measured in the descending aorta in 120 subjects. In an additional group of 6 subjects, transient vena caval occlusion produced 5 sets of pressure-diameter data. We found that the best fit curve of the pooled pressure-diameter data was a third-order polynomial. A polynomial equation was used to calculate the sigmoid line of elasticity in the entire population and after the administration of diltiazem (15 patients) or enalaprilat (10 patients). The sigmoid line of elasticity was significantly different with respect to age (P<0.001), history of hypertension (P<0.004), and hypercholesterolemia (P<0.02). The difference between the transition point and the peak systolic pressure was increased in normal subjects compared with patients (P<0.0001). The sigmoid line shifted leftward and upward with diltiazem, but it remained unchanged with enalaprilat. During an average of 3 years of follow-up, 19 of 88 patients developed stroke (n=4), unstable angina (n=8), acute myocardial infarction (n=4), or acute pulmonary edema (n=3).

CONCLUSIONS

This approach provides a quantitative evaluation of the aortic line of elasticity, which can differentiate the intrinsic from the extrinsic aortic elastic properties. Furthermore, it is a powerful and independent risk factor for cardiovascular events.

Elevated systolic blood pressure as a cardiovascular risk factor

This paper reviews the evolution of attitudes toward the treatment and diagnosis of hypertension. In particular, there is a growing realization that elevated systolic pressure may be a more valuable measurement in evaluating and controlling hypertension than is generally acknowledged. A large number of epidemiologic studies in a wide variety of populations have revealed that systolic blood pressure exerts a stronger influence than diastolic blood pressure. The largest of these, the Framingham Heart Study, showed that in subjects with systolic hypertension, diastolic blood pressure was only weakly related to the risk of cardiovascular events, but in those with diastolic hypertension, the risk of these events was strongly influenced by the level of systolic pressure. Furthermore, cardiovascular event rates were found to increase steeply with systolic pressure and were higher in cases of isolated systolic hypertension than diastolic hypertension. Clinical trials produced similar results, again suggesting that a greater reliance should be placed on systolic pressure in evaluating the risk of cardiovascular problems. This review concludes that the health community needs to be reeducated to consider the importance of systolic and diastolic blood pressure in assessing appropriate management strategies for hypertensive patients.

Prothrombotic factors, endothelial function and left ventricular hypertrophy in isolated systolic hypertension compared with systolic-diastolic hypertension

BACKGROUND

Individuals with systolic-diastolic hypertension (SDH, systolic blood pressure (SBP) >160 mm Hg and diastolic blood pressure (DBP) >90 mm Hg) are at increased risk of thrombotic complications, such as stroke and heart attacks, which may be related to a hypercoagulable state. Individuals with only isolated systolic hypertension (ISH; i.e. SBP >160 mm Hg but DBP <90 mm Hg) are also at significant cardiovascular risk. We hypothesized that patients with ISH would exhibit a prothrombotic state similar to that seen in SDH. A secondary hypothesis was that individuals with ISH had similar echocardiographic parameters to those seen in SDH.

METHODS

We measured indices of haemorheology, endothelial dysfunction, thrombogenesis and platelet activation in 23 individuals with ISH (mean blood pressure 193/82 mm Hg), who were compared with 51 matched patients with SDH (mean blood pressure 198/112 mm Hg) and 34 age- and sex- matched normotensive healthy control individuals (mean blood pressure 130/78 mm Hg). Echocardiographic parameters in patients with ISH were compared to those from patients with SDH.

RESULTS

Mean plasma viscosity (an index of blood rheology, ANOVA, P = 0.001), von Willebrand factor (an index of endothelial damage, P = 0.013), plasminogen activator inhibitor-1 and lipoprotein (a) (both markers of thrombogenesis; Kruskal-Wallis test, both P<0.001) were all significantly raised in ISH and SDH relative to controls. Individuals with SDH also had high mean plasma fibrinogen (P = 0.018) and haematocrit (P = 0.010) levels compared with control individuals. There were no significant differences in levels of fibrin D-dimer or the platelet activation marker soluble P-selectin in the hypertensive patients (i.e. ISH and SDH) compared with control individuals. Patients with ISH had similar M-mode and Doppler echocardiographic parameters compared to patients with SDH.

CONCLUSIONS

We conclude that individuals with ISH have abnormalities in plasma prothrombotic factors and markers of endothelial dysfunction, and echocardiographic parameters, broadly similar to that seen in SDH. This is consistent with the increased risk of thrombotic events (strokes and heart attacks) in patients with ISH.

Age-related differences of blood pressure profile in essential hypertension

The purpose was to assess age-related circadian changes of blood pressure profile (BPP) employing a truncated Fourier series with four harmonics (tFs) in patients with essential hypertension. The study was performed on 32 patients with essential hypertension divided in two groups: (A) 15 patients younger than 55 years and (B) 17 patients older than 60 years. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were monitored every 20 minutes for 24 h with a noninvasive portable device (SpaceLabs 90202). To evaluate the existence of SBP and DBP circadian rhythms a one-sample runs-test was performed and the mesor, amplitude, and acrophase from the overall curve of each patient were obtained by tFs. In both groups, SBP and DBP profiles showed a first peak in the late morning and a second peak in the early evening around the same hours. The two peaks in the SBP profile were higher and the two peaks in the DBP profile were lower in older patients than in younger ones (p < .01, p < .05, p < .3, p < .05). The truncated Fourier series with four harmonics evidences different age-related BP profiles characterized by two peaks with higher SBP and lower DBP in elderly patients. These changes of BPP are in accordance with the reported higher risk of cardiovascular events observed around the same hours.

Comparison of the hemodynamic effects of metoprolol and carvedilol in hypertensive patients

Metoprolol and carvedilol are widely used in the treatment of hypertension, but no randomized comparison of their hemodynamic activity has been previously reported. Their comparative effects on heart rate, systemic blood pressure, and echocardiographically determined aortic and femoral artery blood flow were measured at rest and at 2 and 24 hours after the first dose of each drug, and again after 4 weeks of sustained monotherapy in 12 male and 12 female patients, aged 36-68 years with uncomplicated sustained hypertension according to a randomized single-blind protocol. Nine patients in each drug group achieved the target diastolic blood pressure of < 90 mmHg on the initial doses of each drug; this was achieved in the remainder following doubling of each dose. Neither drug occasioned withdrawal of any patient due to adverse reactions. Both drugs significantly reduced heart rate, although the reduction at 2 hours was significantly greater after metoprolol than after carvedilol. Both drugs reduced systolic pressure throughout the study; the reduction at 2 hours was significantly greater after carvedilol than after metoprolol. In contrast, the diastolic blood pressure was persistently reduced only by carvedilol. The cardiac output, determined as the aortic systolic blood flow, after carvedilol was not significantly different from pretreatment values throughout the study but was significantly reduced in the metoprolol-treated patients at each point of measurement. After metoprolol the systemic and femoral vascular resistances derived from conventional formulae were consistently and significantly increased over pretreatment values throughout the study and were significantly greater than in the carvedilol group at all measurement points. The hemodynamic differences between these two beta-blocking drugs may be explained by the additional vasodilator activity of carvedilol associated with its alpha 1-adrenoceptor blocking activity. The long-term clinical and prognostic implications of these pharmacodynamic differences between beta-adrenoceptor antagonists with and without additional vasodilator activity in the treatment of hypertensive patients remain to be determined.

Twenty-five year mortality from coronary heart disease and its prediction in two Croatian cohorts of middle-aged men

Two cohorts of men aged 40-59 in geographically defined areas of Croatia, former Yugoslavia, were enrolled in 1958 and cardiovascular risk factors were measured. The cohort of Dalmatia, on the Adriatic coast, was made up of 671 men (participation rate 98%), that of Slavonia, in the inland plain, of 696 men (participation rate 91%). Similar examinations were repeated 5 and 10 years after the entry one. A complete follow-up for vital status and causes of death was run for 25 years. Death rates in 25 years from coronary heart disease (CHD) were 90 per 1000 in Dalmatia and 148 per 1000 in Slavonia where also all other major causes of death and all-cause mortality rates were higher (642 vs 465 per 1000 in 25 years). Univariate and multivariate analysis relating ten risk factors to CHD mortality, showed that age and systolic blood pressure were significant predictors in Dalmatia; age, subscapular skinfold and body mass index (inverse) in Slavonia; and age, systolic blood pressure and subscapular skinfold in a multivariate model with lumped cohorts, where dummy variables identifying cohorts indicated a large unexplained extra-risk in Slavonia. In the pooled analysis cigarette smoking and serum cholesterol carried non significant coefficients. Blood pressure change in the first 10 years of follow-up added predictivity to a model exploring the delayed CHD morality occurring between year 10 and 25 of follow-up. Among the base-line measurements only serum cholesterol was significantly different between the two groups (188 mg/dl in Dalmatia and 199 mg/dl in Slavonia).(ABSTRACT TRUNCATED AT 250 WORDS)

Mortality from stroke, coronary heart disease and all causes related to blood pressure and length of follow-up

Measurements of blood pressure in 52,064 men and women in the city of Bergen, Norway, who were 30 to 89 years in 1963, have been related to mortality occurring in different intervals of the follow-up period from 1963 throughout 1983. Blood pressure measurements obtained on one occasion were highly predictive of both coronary heart disease, stroke and all-cause mortality several years after measurements. The relative risk of stroke mortality associated with blood pressure varied little in the first ten to fifteen years, but the predictive power was clearly lower in the last five years of follow-up. The relative risk of death from coronary heart disease was stable in the whole period of follow-up. The risk curves relating coronary heart disease mortality to diastolic blood pressure in men and women aged 60-79 years at screening had the same shape in the first five years as in the rest of the follow-up. No J-shaped association was seen in either time interval.

[Control of arterial hypertension: effectiveness of an intervention performed by family practitioners]

OBJECTIVE

To evaluate the effectiveness of a program to improve hypertension control practices in primary care.

DESIGN

Retrospective quasi-experimental study.

SETTING

Three hospital-based family medicine centres (FMCs)

PARTICIPANTS

Two study groups of 100 randomly-selected adult patients each, who visited the study FMC before implementation of the hypertension program (from April 1, 1983 to March 31, 1984) or afterward (from April 1, 1986 to March 31, 1987). These patients were compared to patients from control FMCs A and B seen during the same time frames (100 patients before and after at FMC A and 60 at FMC B).

INTERVENTIONS

1) Educational sessions for physicians to standardize knowledge of the recommendations of the Canadian Hypertension Society on hypertension treatment and 2) specific operational incentives to improve hypertension control, including a reference guide placed in each physician's office, a specific hypertension follow-up form placed with each patient's chart, a recall card file, and hypertension information handouts.

MAIN OUTCOME MEASURE

Blood pressure measurements recorded in patient charts. Hypertension control is determined from the Canadian Hypertension Society recommendations.

RESULTS

The hypertension control rate was 52% in the study group before program implementation and 34.3% afterward (p = 0.01); the corresponding rates in the two control groups moved from 47.4% to 59.8% (p > 0.05) in Group A and from 40.7% to 39.3% (p > 0.05) in Group B. Patients listed in the recall card file were not controlled more frequently (33.3%) than those not listed (35.3%).

CONCLUSION

This intervention did not improve physician practice regarding hypertension control. Clinicians did not follow the protocol as recommended. Physicians must be convinced that a change in their practice is needed before any specific strategies are introduced to support the change. Different suggestions and alternatives related to hypertension management are discussed.

Birth weight and body mass index in childhood, adolescence, and adulthood as predictors of blood pressure at age 36

STUDY OBJECTIVE

The purpose of this study was to investigate the relation between blood pressure at age 36, and birth weight and body mass index (BMI) in childhood, adolescence and adulthood.

DESIGN

Prospective longitudinal survey over a period of 36 years in England, Scotland, and Wales.

PARTICIPANTS

A nationally representative sample consisting of 3332 men and women born in one week in March 1946. Altogether 82% of these subjects had complete data for the present analysis.

MAIN RESULTS

There was an inverse linear relation between birth weight and blood pressure at age 36. The relation between BMI and blood pressure at age 36 was initially inverse and became increasingly positive throughout life. Weight gain in childhood was positively associated with adult blood pressure, although less important than weight change in later life. The associations between blood pressure and birth weight, and blood pressure and adult BMI were independent, and together they accounted for no more than 4% of the variation in adult blood pressure. Both low birth weight (birth weight < or = 2.5kg) and high BMI at age 36 (BMI > 30kg/m2) were associated with hypertension (> 140/90mmHg), but the per cent population risk of hypertension attributable to low birth weight was less than 5%, and to high BMI less than 12%.

CONCLUSIONS

Low birth weight and high BMI at age 36 were independently related to high blood pressure. A reduction in the percentage of low birthweight babies born in the fourth decade of this century would only have a negligible effect on the incidence of adult hypertension 30-40 years later.

Prevalence, control and awareness of high blood pressure among Canadian adults. Canadian Heart Health Surveys Research Group

OBJECTIVE

To estimate the prevalence and distribution of elevated blood pressure (BP) among Canadian adults and to determine the level of control, treatment, awareness and prevalence of other risk factors among adults with high BP.

DESIGN

Population-based cross-sectional surveys.

SETTING

Nine Canadian provinces, from 1986 to 1990.

PARTICIPANTS

A probability sample of 26,293 men and women aged 18 to 74 years was selected from the health insurance registers in each province. For 20,582 subjects, BP was measured at least twice. Nurses administered a standard questionnaire and recorded two BP measurements using a standardized technique. Two further BP readings, anthropometric measurements and a blood specimen for lipid analysis were obtained from those subjects who attended a clinic.

OUTCOME MEASURES

Mean values of systolic and diastolic BP, prevalence of elevated BP using different criteria, and prevalence of smoking, elevated blood cholesterol, body mass index, physical activity and presence of diabetes by high BP status are reported.

MAIN RESULTS

Sixteen percent of men and 13% of women had diastolic BP of 90 mm Hg or greater or were on treatment (or both). About 26% of these subjects were unaware of their hypertension, 42% were being treated and their condition controlled, 16% were treated and not controlled, and 16% were neither treated nor controlled. Use of non-pharmacologic treatment of high BP with or without medication was low (22%). Hypertensive subjects showed a higher prevalence of elevated total cholesterol, high body mass index, diabetes and sedentary lifestyle than normotensive subjects. Most people with elevated BP were in the 90 to 95 mm Hg range for diastolic pressure and 140 to 160 mm Hg range for systolic pressure. Prevalence of high isolated systolic BP sharply increased in men (40%) and women (49%) 65 to 74 years old.

CONCLUSIONS

The relatively low level of control of elevated BP calls for population and individual strategies, stressing a non-pharmacologic approach and addressing isolated systolic hypertension in the elderly.

Efficacy and safety of quinapril in the elderly hypertensive patient

The efficacy and safety of once-daily administration of the new angiotensin-converting enzyme inhibitor quinapril or quinapril plus hydrochlorothiazide (HCTZ) were assessed in 64 older (greater than 65 years) patients with mild to moderate hypertension in an uncontrolled, open-label study. Treatment was initiated with 20 mg of quinapril once daily and titrated upward to 40 mg of quinapril or 40 mg of quinapril combined with 25 mg of HCTZ according to efficacy. At the end of the 12-week active-treatment phase, 43 patients received 20 mg of quinapril once daily, 12 patients received 40 mg of quinapril once daily, and 4 patients received 40 mg of quinapril combined with 25 mg of HCTZ once daily. Of 48 patients evaluable for efficacy, the mean decrease from baseline in sitting diastolic blood pressure (DBP) was 12.8 mm Hg; 96% of the patients had a blood pressure reduction of greater than or equal to 10 mm Hg, and 98% had a sitting DBP of less than or equal to 90 mm Hg 20 to 28 hours after administration. The decrease in sitting DBP was significant after 1 week and continued for the entire study, as did corresponding changes in sitting systolic blood pressure. We conclude that quinapril administered once daily is well tolerated and effective for the treatment of mild to moderate hypertension in elderly patients.

Dose-response relationships with antihypertensive drugs

A variety of antihypertensive drugs have been introduced into clinical practice at excessively high dose. Examples include most thiazide diuretics, propranolol, oxprenolol, atenolol, methyldopa, hydralazine and captopril. These very high doses have usually resulted from studies in which doses have been increased at regular intervals until the desired antihypertensive effect has been achieved or until unacceptable adverse effects have resulted. Frequently the starting doses were too high and the intervals between dose adjustment too short. In many cases these large doses resulted in unnecessary adverse effects--the adverse biochemical effects of thiazide diuretics, nephrotic syndrome, taste disturbances and neutropenia with captopril, the lupus syndrome with hydralazine and the central nervous system effects of methyldopa. Parallel group design with single doses and sufficient statistical power to distinguish between the upper and lower ends of the antihypertensive dose-response relationship should replace the dose-escalating design.

Management of mild hypertension. Selecting an antihypertensive regimen

This discussion was selected from the weekly staff conferences in the Department of Medicine, University of California, San Francisco. Taken from a transcription, it has been edited by Homer A. Boushey, MD, Professor of Medicine, and Nathan M. Bass, MD, PhD, Associate Professor of Medicine, under the direction of Lloyd H. Smith, Jr, MD, Professor of Medicine and Associate Dean in the School of Medicine.

Systolic blood pressure and cardiovascular mortality among 13,740 Dutch women

Prospective data of cardiovascular mortality in relation to the systolic blood pressure of women are scarce, especially when combined with other risk factors. The association between systolic blood pressure and cardiovascular mortality was therefore studied in a 10-year follow-up of a population of 13,740 Dutch women, born between 1911 and 1925 who participated in a population-based breast cancer screening project (the DOM Project). Age-adjusted mortality rates over the 10-year follow-up period suggest a J-shaped pattern of cardiovascular mortality according to level of systolic blood pressure. Age-adjusted total cardiovascular, coronary, and cerebrovascular mortality rate ratios were significantly greater than 1.0 among women with elevated systolic blood pressure. Within categories of other risk factors (obesity index, diabetes mellitus, current smoking, and use of antihypertensive medicines) the age-adjusted cardiovascular rate ratios did not show confounding by any of these variables. A very high increase in cardiovascular mortality was observed among hypertensive diabetic women. This study shows that elevated systolic blood pressure is associated with increased rates of cardiovascular mortality for women in this age group.

Efficacy of enalapril in essential hypertension and its comparison with atenolol

The effect of enalapril was evaluated in 67 patients with essential hypertension, and its therapeutic efficacy was compared with atenolol in a placebo run-in, single-blind, cross-over trial. Enalapril significantly reduced blood pressure in all grades of essential hypertension. As monotherapy it 'normalized' blood pressure in 88%, 50% and 25% of patients with mild, moderate and severe hypertension respectively. Optimal dose for most of the patients was 20 to 40 mg/day. Comparison with atenolol revealed almost parallel efficacy of the two drugs, although enalapril produced a significantly greater reduction in systolic blood pressure in patients with mild and moderate hypertension (P less than 0.01 in each group). No serious side effects were encountered with either drug. Enalapril, therefore, has a potent and slightly superior antihypertensive effect to that of atenolol, and may be used as a 'first-step' drug in the treatment of hypertensive patients.