Black tea lowers the rate of blood pressure variation: a randomized controlled trial

BACKGROUND

Measures of blood pressure variation have been associated with cardiovascular disease and related outcomes. The regular consumption of black tea can lower blood pressure, but its effects on blood pressure variation have yet to be investigated.

OBJECTIVE

We aimed to assess the effects of black tea consumption on the rate of ambulatory blood pressure variation.

DESIGN

Men and women (n = 111) with systolic blood pressure between 115 and 150 mm Hg at screening were recruited in a randomized, controlled, double-blind, 6-mo parallel-designed trial designed primarily to assess effects on blood pressure. Participants consumed 3 cups/d of either powdered black tea solids (tea) or a flavonoid-free caffeine-matched beverage (control). The 24-h ambulatory blood pressure level and rate of measurement-to-measurement blood pressure variation were assessed at baseline, day 1, and 3 and 6 mo.

RESULTS

Across the 3 time points, tea, compared with the control, resulted in lower rates of systolic (P = 0.0045) and diastolic (P = 0.016) blood pressure variation by ~10% during nighttime (2200-0600). These effects, which were immediate at day 1 and sustained over 6 mo, were independent of the level of blood pressure and heart rate. The rate of blood pressure variation was not significantly altered during daytime (0800-2000).

CONCLUSIONS

These findings indicate that a component of black tea solids, other than caffeine, can influence the rate of blood pressure variation during nighttime. Thus, small dietary changes have the potential to significantly influence the rate of blood pressure variation. This trial was registered at the Australian New Zealand Clinical Trials Registry as ACTR12607000543482.

Stroke and coronary heart disease: predictive power of standard risk factors into old age--long-term cumulative risk study among men in Gothenburg, Sweden

Aims

The aim of this study was to examine the short-term and long-term cumulative risk of coronary heart disease (CHD) and stroke separately based on age, sex, smoking status, systolic blood pressure, and total serum cholesterol.

Methods and results

The Primary Prevention Study comprising 7174 men aged between 47 and 55 free from a previous history of CHD, stroke, and diabetes at baseline examination (1970–73) was followed up for 35 years. To estimate the cumulative effect of CHD and stroke, all participants were stratified into one of five risk groups, defined by their number of risk factors. The estimated 10-year risk for high-risk individuals when adjusted for age and competing risk was 18.1% for CHD and 3.2% for stroke which increased to 47.8 and 19.6%, respectively, after 35 years. The estimates based on risk factors performed well throughout the period for CHD but less well for stroke.

Conclusion

The prediction of traditional risk factors (systolic blood pressure, total serum cholesterol, and smoking status) on short-term risk (0–10 years) and long-term risk (0–35 years) of CHD of stroke differs substantially. This indicates that the cumulative risk in middle-aged men based on these traditional risk factors can effectively be used to predict CHD but not stroke to the same extent.

Short-term and long-term stroke survival: the belgrade prognostic study

Background and Purpose

The aims of this study were to determine the 28-day and 1-year survival rates after first-ever ischemic stroke and to identify their baseline predictors.

Methods

We prospectively and consecutively collected data on 300 patients with first-ever acute ischemic stroke admitted to 2 major neurological institutions for cerebrovascular diseases in Belgrade during March 2008. The Kaplan-Meier method was used to estimate the cumulative 28-day and 1-year survival rates, and the predictive values of different variables were assessed by Cox proportional-hazards regression model.

Results

The cumulative 28-day and 1-year survival rates of ischemic stroke patients in the cohort were 81.0% and 78.3%, respectively. The multivariate predictive model revealed that hypertension (p=0.017), National Institutes of Health Stroke Scale score (p=0.001), and in-hospital medical complications (p=0.029) were significant unfavorable independent outcome predictors, while early physical therapy (p=0.001) was a significant favorable prognostic factor for the 28-day mortality in our patients. Multivariate Cox regression analysis showed that age (p=0.001), National Institutes of Health Stroke Scale score (p=0.001), and in-hospital complications (p=0.008) remained significant predictors of 1-year mortality.

Conclusions

The findings support the need for optimal control of vascular risk factors and treatment of atherosclerotic disease as well as appropriate prevention and management of in-hospital complications of stroke.

Synergic effects of levamlodipine and bisoprolol on blood pressure reduction and organ protection in spontaneously hypertensive rats

AIMS

Stroke is a major cause of disability and death worldwide. Hypertension is one of the most important risk factors for stroke. The objective of this work was to study the synergic effects of levamlodipine and bisoprolol on blood pressure reduction and organ protection in spontaneously hypertensive rats (SHR).

METHODS

Blood pressure was continuously monitored in conscious SHR. For acute study, a single dose of drugs was administrated via an intragastric catheter. For chronic study (4 months), drugs were delivered via rat chow.

RESULTS

A single dose of levamlodipine (from 1 mg/kg), bisoprolol (from 0.125 mg/kg), and their combinations significantly decreased blood pressure. The levamlodipine-induced tachycardia and the bisoprolol-induced bradycardia were temporized by the combination of these two drugs. Upon chronic treatment, this combination also decreased blood pressure variability and reduced organ damage.

CONCLUSION

Levamlodipine and bisoprolol produce synergic effects on blood pressure reduction and organ protection in SHR.

The use of epidemiological measures to estimate the impact of primary prevention interventions on CHD, stroke and cancer outcomes: experiences from Herefordshire, UK

Background: CHD, stroke and cancers are the major causes of mortality in the UK and are responsible for significant amounts of morbidity and healthcare costs. This study examines the proportion of CHD, stroke and cancer owing to specific risk factors in Herefordshire, UK. It estimates the population impact of a number of interventions being implemented to reduce these risk factors, through the NHS Health Check program and the Herefordshire Health Improvement Plan. The present study also aims to demonstrate the value of epidemiological measures in providing evidence-based public health information in policy-making to aid decision makers when prioritizing investments and optimal use of resources.

Methods: The epidemiological measures–‘Population Attributable Risk’ and ‘Population Impact Measures’–were used to assess the impact of interventions to reduce the burden of CHD, stroke and cancer.

Results: Implementation of the NHS Health Check program will prevent 63 CHD events, 90 MI events and 125 stroke events, and one lung cancer over a period of 5 years. Reducing specific risk factors by 5% annually through the Health Improvement Plan will prevent 65 CHD events, 25 MI events, 140 stroke events, four lung cancer, one breast cancer and four colorectal cancer cases in Herefordshire if targets are met over a period of 5 years.

Conclusion: Physical inactivity and obesity are the major causes of CHD and stroke events (incidence and mortality) in Herefordshire. Their impact is greater than the combined effect of hypercholesterolemia and hypertension.

Epidemiological measures used in this study proved to be excellent tools in providing evidence-based public health information. Their use is strongly recommended to support prioritization of primary prevention interventions.

Importance of riboflavin kinase in the pathogenesis of stroke

AIMS

To explore risk factors for stroke independent of hypertension and the relationship between riboflavin kinase (RFK) and stroke.

METHODS

Gene expression profiling in the brains of spontaneously hypertensive rats (SHR) and stroke-prone spontaneously hypertensive rats (SHRSP) was comparatively analyzed by gene chips. The differentially expressed gene RFK was further verified by q-PCR and Western blot. The protective role of RFK-regulated flavins (including riboflavin, flavin mononucleotide, and flavin adenine dinucleotide) in stroke was observed in middle cerebral artery occlusion (MCAO) mice. Influence of flavins on apoptosis and death in oxygen and glucose deprivation (OGD)-treated neurons was examined by flow cytometry. Bax and Bcl-2 proteins were detected by Western blot.

RESULTS

Of the 76 differentially expressed genes, 41 genes were upregulated, and 35 genes were downregulated in SHRSP as compared with SHR. RFK was significantly downregulated in SHRSP. Flavins markedly decreased infarct area in MCAO mice, inhibited apoptosis and death in OGD-treated neurons, and decreased Bax protein expression.

CONCLUSIONS

Physiological downregulation of RFK may be a new potential risk factor for stroke, which probably affects the absorbance and utility of riboflavin and further destroys the protective effect of flavins on stroke. RFK might act as a therapeutic target for stroke.

Burden of Stroke in Malaysia

Stroke is one of the top five leading causes of death and one of the top 10 causes for hospitalization in Malaysia. Stroke is also in the top five diseases with the greatest burden of disease, based on disability-adjusted life years. However, prospective studies on stroke in Malaysia are limited. To date, neither the prevalence of stroke nor its incidence nationally has been recorded. Hypertension is the major risk factor for stroke. The mean age of stroke patients in Malaysia is between 54·5 and 62·6 years. Traditional medicine is commonly practiced. With the increasing number of stroke cases annually, more government and nongovernment organizations should be involved in primary and secondary prevention strategies.

Adherence to the mediterranean diet in relation to ischemic stroke nonfatal events in nonhypercholesterolemic and hypercholesterolemic participants: results of a case/case-control study

The aim of the present work was to evaluate the association between adherence to the Mediterranean diet and the development of ischemic stroke according to cholesterol levels. During 2009-2010, 500 participants were enrolled; 250 were consecutive patients (77 ± 9 years, 55.6% men) with a first ischemic stroke and 250 population-based, control participants, matched to the patients by age and sex. Sociodemographic, clinical, dietary, and other lifestyle characteristics were measured. Adherence to the Mediterranean diet was assessed by the validated MedDietScore (theoretical range: 0-55). After various adjustments, each 1/55 unit increase in the MedDietScore was associated with 17% lower likelihood of having an ischemic stroke in nonhypercholesterolemic participants (95%CI: 0.72-0.96) and 10% lower likelihood in participants with hypercholesterolemia (95%CI: 0.81-0.99). The present work highlights the cardioprotective benefits from the adoption of the Mediterranean diet, by showing its beneficial effect regarding ischemic stroke development, regardless of the presence of hypercholesterolemia.