Ups and downs of hypertension control in Canada: critical factors and lessons learned

As the leading risk for death, population control of increased blood pressure represents a major challenge for all countries of the Americas. In the early 1990’s, Canada had a hypertension control rate of 13%. The control rate increased to 68% in 2010, accompanied by a sharp decline in cardiovascular disease. The unprecedented improvement in hypertension control started around the year 2000 when a comprehensive program to implement annually updated hypertension treatment recommendations started. The program included a comprehensive monitoring system for hypertension control. After 2011, there was a marked decrease in emphasis on implementation and evaluation and the hypertension control rate declined, driven by a reduction in control in women from 69% to 49%. A coalition of health and scientific organizations formed in 2011 with a priority to develop advocacy positions for dietary policies to prevent and control hypertension. By 2015, the positions were adopted by most federal political parties, but implementation has been slow.

This manuscript reviews key success factors and learnings. Some key success factors included having broad representation on the program steering committee, multidisciplinary engagement with substantive primary care involvement, unbiased up to date credible recommendations, development and active adaptation of education resources based on field experience, extensive implementation of primary care resources, annual review of the program and hypertension indicators and developing and emphasizing the few interventions important for hypertension control. Learnings included the need for having strong national and provincial government engagement and support, and retaining primary care organizations and clinicians in the implementation and evaluation.

[São Paulo call to action for the prevention and control of high blood pressure: 2020Chamado à ação de São Paulo para prevenção e controle da hipertensão arterial: 2020]

About 1/4th of adults have high blood pressure which is the single most important risk for death (including heart disease and stroke).There are effective policies that could facilitate people making healthy choices to prevent raised blood pressure, and if fully implemented, could largely prevent hypertension from occurring.Hypertension is easy to screen and treat for BUT only about 50% of adults with hypertension are aware of their condition and only about 1 in 7 is adequately treated.Preventing and controlling high blood pressure is the major mechanism for NCD prevention and control and a model for other NCD risks.Effective lifestyle and drug treatments could prevent and control hypertension in most individuals if systematically applied to the population, simple interventions are feasible in all settings, and can be used to enhance primary care.Urgent sustained action is needed is needed for effective public policies and health system changes to prevent and control hypertension.

Methodology of the 2009 Survey on Living with Chronic Diseases in Canada--hypertension component

INTRODUCTION

The Survey on Living with Chronic Diseases in Canada--hypertension component (SLCDC-H) is a 20-minute cross-sectional telephone survey on hypertension diagnosis and management. Sampled from the 2008 Canadian Community Health Survey (CCHS), the SLCDC-H includes Canadians (aged ≥ 20 years) with self-reported hypertension from the ten provinces.

METHODS

The questionnaire was developed by Delphi technique, externally reviewed and qualitatively tested. Statistics Canada performed sampling strategies, recruitment, data collection and processing. Proportions were weighted to represent the Canadian population, and 95% confidence intervals (CIs) were derived by bootstrap method.

RESULTS

Compared with the CCHS population reporting hypertension, the SLCDC-H sample (n = 6142) is slightly younger (SLCDC-H mean age: 61.2 years, 95% CI: 60.8-61.6; CCHS mean age: 62.2 years, 95% CI: 61.8-62.5), has more post-secondary school graduates (SLCDC-H: 52.0%, 95% CI: 49.7%-54.2%; CCHS: 47.5%, 95% CI: 46.1%-48.9%) and has fewer respondents on hypertension medication (SLCDC-H: 82.5%, 95% CI: 80.9%-84.1%; CCHS: 88.6%, 95% CI: 87.7%-89.6%).

CONCLUSION

Overall, the 2009 SLCDC-H represents its source population and provides novel, comprehensive data on the diagnosis and management of hypertension. The survey has been adapted to other chronic conditions--diabetes, asthma/chronic obstructive pulmonary disease and neurological conditions. The questionnaire is available on the Statistics Canada website; descriptive results have been disseminated by the Public Health Agency of Canada.

Trends in diabetes treatment in Canadians, 1994-2004

OBJECTIVE

To examine trends in the treatment of diabetes using the biannual interviews of the longitudinal National Population Health Survey (NPHS), 1994-2004 as they relate to changes in Clinical Practice Guidelines (CPGs).

METHODS

A sample of 17 276 Canadians 18 years and older was selected for repeated interviews at two-year intervals from 1994 to 2004 for the NPHS. The population used for this study includes all respondents aged 40 to 79 for any of the cycles.

RESULTS

CPGs issued by the Canadian Diabetes Association in 1998 and 2004 recommend a stepwise introduction of lifestyle changes, to be followed by single then multiple oral antidiabetic agents (OA), and finally insulin until adequate control is achieved. While the use of OA increased, only a small proportion indicated diet or physical exercise as part of their treatment; those with no drug treatment reported less diet modification and physical exercise. Antihypertensives and statin use in Canadians with diabetes increased to double that of Canadians overall, but remained underutilized.

CONCLUSION

This study provides an update on the treatment of diabetes in Canada between 1994 and 2004. While some changes in diabetes treatment were compatible with CPGs, there is room for improvement, especially in lifestyle modifications.

Antihypertensive medication use by recently diagnosed hypertensive Canadians

PURPOSE

The Canadian Hypertension Education Program (CHEP) was initiated in 1999 to improve hypertension management in Canada. The objective of the present study was to compare antihypertensive pharmacotherapy in Canada before and after the CHEP.

METHODS

Data were obtained from the longitudinal National Population Health Surveys, which consisted of five cycles at two-year intervals from 1994 to 2002. Recent hypertensive respondents 20 years of age and older were identified the first time hypertension was reported or treated, and were included in a study population of 1453 newly diagnosed hypertensive patients. Persistence with medication use was assessed in the cycle after the first report of hypertension.

RESULTS

Antihypertensive medication use within two years of hypertension diagnosis increased with age, from 35% in patients 20 to 39 years of age, to 72.1% in those 80 years of age and older. Antihypertensive medication use increased after the CHEP (from 49.2% to 53.8% of the population), as did the use of multiple antihypertensive medications (from 7.5% to 10.6%). The most commonly used antihypertensive medication for men was angiotensin-converting enzyme inhibitors (beta-blockers were second), but the most common medication for women was diuretics. The overall persistence rate for antihypertensive medication use was 73.2% over two years, which had increased after the CHEP (from 70.4% to 75.4%).

CONCLUSIONS

The implementation of the CHEP was followed by increased antihypertensive medication use, increased use of multiple antihypertensive medications and improved persistence with medication use. Although causality cannot be established with the design of the present study, improved hypertension management in Canada is heartening. Sex-related differences were observed in prescribed medications, even though clinical guidelines do not differentiate between sexes.

Estimate of the benefits of a population-based reduction in dietary sodium additives on hypertension and its related health care costs in Canada

BACKGROUND

Hypertension is the leading risk factor for mortality worldwide. One-quarter of the adult Canadian population has hypertension, and more than 90% of the population is estimated to develop hypertension if they live an average lifespan. Reductions in dietary sodium additives significantly lower systolic and diastolic blood pressure, and population reductions in dietary sodium are recommended by major scientific and public health organizations.

OBJECTIVES

To estimate the reduction in hypertension prevalence and specific hypertension management cost savings associated with a population-wide reduction in dietary sodium additives.

METHODS

Based on data from clinical trials, reducing dietary sodium additives by 1840 mg/day would result in a decrease of 5.06 mmHg (systolic) and 2.7 mmHg (diastolic) blood pressures. Using Canadian Heart Health Survey data, the resulting reduction in hypertension was estimated. Costs of laboratory testing and physician visits were based on 2001 to 2003 Ontario Health Insurance Plan data, and the number of physician visits and costs of medications for patients with hypertension were taken from 2003 IMS Canada. To estimate the reduction in total physician visits and laboratory costs, current estimates of aware hypertensive patients in Canada were used from the Canadian Community Health Survey.

RESULTS

Reducing dietary sodium additives may decrease hypertension prevalence by 30%, resulting in one million fewer hypertensive patients in Canada, and almost double the treatment and control rate. Direct cost savings related to fewer physician visits, laboratory tests and lower medication use are estimated to be approximately $430 million per year. Physician visits and laboratory costs would decrease by 6.5%, and 23% fewer treated hypertensive patients would require medications for control of blood pressure.

CONCLUSIONS

Based on these estimates, lowering dietary sodium additives would lead to a large reduction in hypertension prevalence and result in health care cost savings in Canada.

Public education on hypertension: a new initiative to improve the prevention, treatment and control of hypertension in Canada

High blood pressure is one of the leading risk factors for death. Nevertheless, there is a lack of awareness of hypertension as a risk factor, as well as significant misconceptions about hypertension in the Canadian population. Furthermore, according to the Canadian Heart Health Surveys (1985 to 1992), 42% of hypertensive adult Canadians are unaware of their hypertensive status. A collaboration between Blood Pressure Canada, the Heart and Stroke Foundation of Canada, the Canadian Hypertension Society and the Canadian Hypertension Education Program has been formed to improve public and patient awareness and knowledge of hypertension. The effort will involve the translation of Canadian Hypertension Education Program recommendations for the prevention and management of hypertension to a public level with a broad and evolving dissemination strategy; the training of health professionals to speak to the public and patients on hypertension, coupled with opportunities to speak in forums organized in their local communities; and, media releases and information on hypertension in association with World Hypertension Day and the release of the annually updated public recommendations. Based on higher rates of awareness of hypertension in countries with sustained public education programs on hypertension, it is anticipated that this evolving program will result in improvement in the rates of awareness, treatment and control of hypertension and, ultimately, in lower cardiovascular disease rates in Canada. Public health programs that could reduce the prevalence of hypertension will be integrated into key public recommendations. The program outcomes will be monitored using Statistics Canada national surveys and by specific surveys examining hypertension knowledge in the Canadian population.

Building capacity for awareness and risk factor identification in the community: the blood pressure assessment program of the Calgary Fire Department

In 1995, the Calgary Fire Department developed a program to assess blood pressure in community fire stations, selected businesses and public venues. The program has gradually expanded. Currently, all 30 fire stations across Calgary, Alberta assess blood pressures for the public seven days per week throughout the year. Since 1995, there have been 10,883 measurements in 3477 people. Most people (2106) assessed had hypertensive readings, and 72 had readings greater than 220 mmHg systolic or greater than 120 mmHg diastolic, and were referred for immediate medical assessment. The program has been recently integrated into a more global vision for the prevention and control of cardiovascular disease in Calgary. Future plans include offering lipid assessments, assisting other communities to adopt the program and using the program to provide physical measures (of blood pressure, glucose, total and high density lipoprotein cholesterol, height and weight) to an ongoing questionnaire that surveys the health of Calgarians. The history of the program, its training methods, quality control, preliminary results and future plans are presented in detail to provide an example of a community-based program that could aid in the detection, monitoring and awareness of hypertension.

The 2000 Canadian recommendations for the management of hypertension: part two--diagnosis and assessment of people with high blood pressure

OBJECTIVE

To provide updated, evidence-based recommendations for the diagnosis and assessment of high blood pressure in adults.

OPTIONS

For people with high blood pressure, the assignment of a diagnosis of hypertension depends on the appropriate measurement of blood pressure, the level of the blood pressure elevation, the duration of follow-up and the presence of concomitant vascular risk factors, target organ damage and established atherosclerotic diseases. For people diagnosed with hypertension, defining the overall risk of adverse cardiovascular outcomes requires laboratory testing, a search for target organ damage and an assessment of the modifiable causes of hypertension. Out-of-clinic blood pressure assessment and echocardiography are options for selected patients.

OUTCOMES

People at increased risk of adverse cardiovascular outcomes and were identified and quantified.

EVIDENCE

Medline searches were conducted from the period of the last revision of the Canadian recommendations for the management of hypertension (May 1998 to October 2000). Reference lists were scanned, experts were polled, and the personal files of the subgroup members and authors were used to identify other studies. All relevant articles were reviewed and appraised, using prespecified levels of evidence, by content experts and methodological experts.

VALUES

A high value was placed on the identification of people at increased risk of cardiovascular morbidity and mortality.

BENEFITS, HARMS AND COSTS

The identification of people at higher risk of cardiovascular disease will permit counselling for lifestyle manoeuvres and the introduction of antihypertensive drugs to reduce blood pressure for patients with sustained hypertension. In certain settings, and for specific classes of drugs, blood pressure lowering has been associated with reduced cardiovascular morbidity and/or mortality.

RECOMMENDATIONS

The present document contains detailed recommendations pertaining to aspects of the diagnosis and assessment of patients with hypertension, including the accurate measurement of blood pressure, criteria for the diagnosis of hypertension and recommendations for follow-up, routine and optional laboratory testing, assessment for renovascular hypertension, home and ambulatory blood pressure monitoring, and the role of echocardiography in hypertension.

VALIDATION

All recommendations were graded according to strength of the evidence and voted on by the Canadian Hypertension Recommendations Working Group. Only the recommendations achieving high levels of consensus are reported here. These guidelines will be updated annually.

ENDORSEMENT

These recommendations are endorsed by the Canadian Hypertension Society, The Canadian Coalition for High Blood Pressure Prevention and Control, The College of Family Physicians of Canada, The Heart and Stroke Foundation of Canada, The Adult Disease Division and Bureau of Cardio-Respiratory Diseases and Diabetes at the Centre for Chronic Disease Prevention and Control of Health Canada.

Use of vitamins, minerals and herbs: a survey of patients attending family practice clinics

OBJECTIVE

To examine the use of vitamin, mineral and herbal supplements in patients attending family practice clinics.

DESIGN

A prospective 1-year cohort study.

SETTING

Sixteen family practices in Calgary.

PARTICIPANTS

One hundred and eighteen patients (more than 18 years of age) were initially interviewed; 12 patients were lost to follow-up.

MAIN OUTCOME MEASURES

Number and type of supplements used, duration of use, sources of patient information, beliefs about supplement efficacy and safety, reporting use to physicians, costs and changes in pattern of use over 1 year.

RESULTS

Supplement use was unrelated to age, but more women (73%) used supplements than men (44%). Relative to age, more patients younger than 50 years believed supplements were safer than prescription medications (82% v. 43%, p = 0.0005). Younger patients were less likely than those over 50 years old to have received supplement information from physicians (10% v. 37%, p = 0.0008) and were less compliant than older patients with manufacturers' recommended dosages (p = 0.02). Whereas 74% of those over the age of 50 years informed their physician that they used supplements, only 30% of younger patients did so (p = 0.0006). At 1-year follow-up, the number of supplements taken per patient increased (p < 0.05), and there was a tendency for more patients to take supplements (61% v. 70%, p = NS).

CONCLUSIONS

The majority of patients attending family practices in Calgary use vitamin, mineral or herbal supplements, and monitoring of supplement use by health care professionals is minimal. Young patients, in particular, tend not to report their use of supplements. They also believe the supplements are safer and more effective than prescription medications and obtain information from nonmedical sources. Physicians should enhance patient understanding of these products and include supplement use in all medical histories. In particular, younger patients require more reliable information on supplements.

Nutrition communication for a Latino community: formative research foundations

Formative research techniques were used to develop a tailored health communication nutrition intervention for Latinas and their families. Members of the target community were recruited to participate in focus groups, depth interviews, and participant observations. Women, in particular, were observed preparing meals in their homes and purchasing groceries. The objective was to identify variables that could be used for targeting, segmenting, and tailoring the intervention. Results from these efforts were used to develop a theory-based intervention, which is described at the conclusion of the article.

Self-measurement of blood pressure: accuracy, patient preparation for readings, technique and equipment

OBJECTIVE

Self-measurement of blood pressure is commonly performed by those persons with hypertension and is advocated in many national hypertension guidelines. We examined accuracy of readings, patient knowledge, and preparation for readings, technique and equipment.

DESIGN

The study was a prospective observational design. Sixty-nine hypertensive patients were recruited from a tertiary referral center and by newspaper advertisement. All patients had previously self-measured their blood pressure. The patients initially measured their blood pressure under direct supervision in a clinic using their usual preparation, technique and their own equipment. Then after a five-min rest, blood pressures were measured twice both by research nurse and the patient in an alternating sequence. The nurse used a standardized blood pressure measurement technique.

RESULTS

Inadequate patient knowledge and performance of measurement technique and inaccurate equipment was common. The average initial patient systolic reading prior to the five-minute rest was higher than that of the trained nurse (9.1 +/- 13 mmHg systolic, p < 0.001 and 1.5 +/- 8.0 mmHg diastolic, p = 0.12). Almost half (42%) of the initial patient blood pressure readings differed in classification of hypertension/normotension from the nurse. The difference between the patient and nurse readings after the five-min rest was 3.8 +/- 11.8 / 1.1 +/- 6.8 mmHg.

CONCLUSIONS

Care must be taken in interpreting patient self-measured blood pressure unless there has been adequate training and assessment of patient and equipment accuracy. Studies of health care professionals reveal similar problems therefore widespread efforts to standardize blood pressure measurement are necessary.

Evaluation of a first aid and home safety program for Hispanic migrant adolescents

BACKGROUND

Unintentional injuries are the major cause of death among children, adolescents, and young adults. This article presents an evaluation of an injury-prevention program for 11- to 16-year-old, Hispanic migrant youth.

DESIGN

Randomized controlled trial with two conditions: first aid and home safety training and tobacco and alcohol prevention. Participants were assessed at baseline, at immediate post-intervention, and at 1-year follow-up.

PARTICIPANTS

A total of 660 Hispanic adolescent and parent pairs participated in a program entitled Sembrando Salud (sowing the seeds of health).

INTERVENTION

The intervention consisted of two conditions: first aid and home safety training and tobacco and alcohol prevention. Both groups were exposed to an eight-session, multimedia program presented by bilingual, bicultural college students. The sessions consisted of lectures, discussions, and skills development and practice.

OUTCOME MEASURES

To examine the efficacy of the first aid and home safety intervention, adolescents were assessed for changes in first aid confidence, knowledge of items in a first aid kit, knowledge of how to respond in an emergency situation, acquisition of a first aid kit, and behavioral skills testing in response to two emergency scenarios.

RESULTS

Similar changes in confidence were observed in both groups after the intervention. Participants in the first aid and home safety program were better able to identify items to include in a first aid kit, how to respond in an emergency situation, and reported fewer erroneous victim-caring procedures than the tobacco and alcohol prevention group.

CONCLUSIONS

Sembrando Salud was successful at achieving and maintaining change in confidence and knowledge of first aid and emergency response skills over a yearlong period.

The management of hypertension in Canada: a review of current guidelines, their shortcomings and implications for the future

Clinicians are exposed to numerous hypertension guidelines. However, their enthusiasm for these guidelines, and the impact of the guidelines, appears modest at best. Barriers to the successful implementation of a guideline can be identified at the level of the clinician, the patient or the practice setting; however, the shortcomings of the guidelines themselves have received little attention. In this paper, we review the hypertension guidelines that are most commonly encountered by Canadian clinicians: the "1999 Canadian Recommendations for the Management of Hypertension," "The Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure" in the United States and the "1999 World Health Organization-International Society of Hypertension Guidelines for the Management of Hypertension." The key points of these guidelines are compared and the shortcomings that may impede their ability to influence practice are discussed. The main implications for future guideline developers are outlined.

Effect on lipid, complete blood count and blood proteins of a standardized preparation for drawing blood: a randomized controlled trial

OBJECTIVE

To compare a standardized recommended procedure for drawing blood to measure blood lipid and lipoprotein levels with the procedure commonly used in clinical practice. The aim was to see if hemoconcentration and spuriously elevated lipid levels could be avoided.

DESIGN

An open randomized crossover clinical trial.

SETTING

The University of Calgary.

PATIENTS

Twenty-five patients with dyslipidemia.

INTERVENTIONS

Blood drawing using a standardized procedure in which the patient remained seated for 5 minutes before blood collection and tourniquet use was minimized or avoided.

MAIN OUTCOME MEASURES

Differences in lipid levels between the usual clinical procedure and the recommended procedure for drawing blood.

RESULTS

Prior to drawing blood, laboratories have sat patients for an average of 1.4 minutes (95% CI, 0.9 to 1.9) and used a tourniquet in every patient. In the standardized procedure, patients rested for an average of 5.6 minutes (95% CI 5.0 to 6.2), and a tourniquet was used briefly in only 3 of 23 patients. There were no differences in lipid and lipoprotein values and no clinically significant difference in hemoglobin or albumin levels or in the calculation of hemoconcentration.

CONCLUSIONS

Efforts to rest patients and avoid tourniquet use when drawing blood for assessment of lipid levels are unlikely to be useful.

A novel process for updating recommendations for managing hypertension: rationale and methods

BACKGROUND

There are numerous hypertension consensus recommendations intended for practising physicians. However, recommendations in their current format have limited impact on improving hypertension control.

MATERIALS AND METHODS

A group of national societies, headed by the Canadian Hypertension Society, the Heart and Stroke Foundation of Canada, the Canadian Coalition for High Blood Pressure Prevention and Control, and Health Canada has developed strategies to maintain annually updated recommendations for hypertension management and to provide greater opportunities for their implementation into clinical practice. The process is overseen by a steering committee. Subcommittees have been formed for each of a list of topics seen as important to the control of hypertension. The subcommittees, with the aid of a central librarian, conduct annual literature reviews in accordance with Cochrane Collaboration strategies. Modified existing and new recommendations are forwarded to a group with expertise in clinical epidemiology. Grades of evidence are assigned to each recommendation. Revised recommendations based on the above process will be presented annually at the conjoint Canadian Hypertension Society/Canadian Cardiovascular Congress meeting. Under the leadership of the Cardiovascular Disease Division of the Laboratory Centre for Disease Control, Health Canada, a committee has been charged with the implementation process.

CONCLUSIONS

The improvements of the current process over previous national hypertension recommendations are four-fold. First, the recommendations will be updated annually. Second, the methodology has been improved. Third, the grading system can be used in the evaluation of complex study designs. Finally, the implementation process is extended. The authors are optimistic that these changes will contribute to the improvement of hypertension control in the Canadian population.

Predictors of cigarette and alcohol susceptibility and use among Hispanic migrant adolescents

BACKGROUND

Little is known about interpersonal and broader sociocultural factors related to protection from or use of tobacco and alcohol among immigrant adolescents. This study presents the baseline predictors of tobacco and alcohol use and susceptibility to tobacco and alcohol among Hispanic migrant adolescents.

METHODS

The sample consisted of 660 Hispanic adolescents (51% male) between the ages of 11 and 16 years enrolled in the Migrant Education Program through the County Office of Education. Slightly more than 75% of the study sample was first generation Hispanics and 79% preferred to speak Spanish. An interviewer-administered survey assessed the following information: standard demographic characteristics, modeling of cigarette smoking (including parental and peer smoking), attitudes (including self-standards and anticipated outcomes), acculturation, communication with parents, amount of social support, and satisfaction with social support.

RESULTS

Significant predictors of susceptibility to tobacco and smoking status included age, gender, attitudes toward cigarettes (e.g., anticipated outcomes, self-standards), satisfaction with social support, and parent-child communication. Factors that were also significant predictors of susceptibility to alcohol and drinking status were age, attitudes toward drinking, satisfaction with social support, and level of parent-child communication. In addition, peer and household use of alcohol predicted adolescent outcomes.

CONCLUSIONS

Based on these results it is suggested that tobacco and alcohol prevention efforts for first-generation Hispanic adolescents should target not only usual concerns (e.g., availability, peer pressure, modeling, expectancies), but also parent-child communication.

Evaluation of a tobacco and alcohol use prevention program for Hispanic migrant adolescents: promoting the protective factor of parent-child communication

BACKGROUND

Interventions designed to prevent tobacco and alcohol use targeting high-risk adolescents are limited. In addition, few studies have attempted to improve parent-child communication skills as a way of improving and maintaining healthy youth decision-making.

METHODS

A total of 660 Hispanic migrant families participated in a randomized pre-post control group study that was utilized to determine the impact of the intervention on parent-child communication. Both treatment and attention-control groups of youth were exposed to an eight-session culturally sensitive program presented by bilingual/bicultural college students. Parents jointly attended three of the eight sessions and participated in helping their child complete homework assignments supporting the content of each session. The content of the treatment intervention included (1) information about tobacco and alcohol effects, (2) social skills training (i.e., refusal skills), and (3) the specific development of parent-child communication skills to support healthy youth decisions.

RESULTS

Significant intervention by household size interactions for both parent and youth perceptions of communication were found indicating that the treatment was effective in increasing communication in families with fewer children. Based on the effect size and the previously established relationship between communication and susceptibility to tobacco and alcohol use, it was determined that the intervention effect could be translated into a future 5 to 10% decrease in susceptibility for these smaller families.

CONCLUSIONS

A culturally sensitive family-based intervention for migrant Hispanic youth was found to be effective in increasing perceived parent-child communication in families with fewer children. It is expected that increases in this important protective factor will lead to later observed decreases in tobacco and alcohol use.

The relationship between COMT genotype and the clinical effectiveness of tolcapone, a COMT inhibitor, in patients with Parkinson's disease

Patients with Parkinson's Disease (PD) have a variable response to tolcapone, a catechol-O-methyltransferase (COMT) inhibitor. In addition, a subset of patients develop severe diarrhea as a side effect. Two codominant alleles for the COMT gene exist, coding for low and high activity, resulting in low-, medium-, and high-activity genotypes. This study investigates the relationship between this variation in genotype and clinical effects in patients with PD taking tolcapone. To investigate the relationship between COMT polymorphism and clinical response, 24 patients who completed tolcapone clinical trials provided blood samples for COMT genotype analysis. Change in levodopa dose and United Parkinson Disease Rating Scale (UPDRS) Part III (motor subscale) were analyzed at baseline, at 1-2 weeks, and 6 months after initiation of tolcapone. Genotype analysis was performed on seven patients who had diarrhea as a side effect. There was no significant correlation between genotype and improvement in UPDRS score (p = 0.29) according to a linear models approach that adjusted for the subject's severity of PD, tolcapone dose (either 100 or 200 mg three times daily) and initial differences in baseline scores. No significant difference was seen in change in daily levodopa intake and genotype. There was also no relation between diarrhea and COMT genotype. These results indicate that, in the treatment of Parkinson's disease, COMT genotype is not a major contributor to the clinical response to tolcapone.

Clinical problem solving based on the 1999 Canadian recommendations for the management of hypertension

The 1999 Canadian Recommendations for the Management of Hypertension are notable for the trends that they represent with regard to the evolution of the management of hypertension. Diagnostically, the Recommendations endorse the greater use of non-office-based measures of blood pressure control and greater emphasis on the assessment of other atherosclerotic risk factors, both when considering prognosis in hypertension and in the choice of therapy. On the treatment side of the equation, lower targets for blood pressure control have been advocated in subgroups of hypertensive patients, particularly in those with diabetes and renal disease. In conjunction with the recently published recommendations on lifestyle management, there is a greater emphasis on lifestyle modification, both as initial and adjunctive therapy in hypertension. Implicit in the recommendations for therapy is the principle that for the vast majority of hypertensive patients treated pharmacologically, practitioners should not follow a stepped-care approach. Instead, therapy should be individualized, primarily based on consideration of concurrent diseases, both cardiovascular and noncardiovascular (Tables 1 and 2). Through the consensus process, there was a general appreciation of how far we have come in the development of evidence-based recommendations for hypertension management. However, there was also an increasing appreciation of how far we have to go in effectively translating these recommendations into better blood pressure control.

Lifestyle modifications to prevent and control hypertension. 3. Recommendations on alcohol consumption. Canadian Hypertension Society, Canadian Coalition for High Blood Pressure Prevention and Control, Laboratory Centre for Disease Control at Health Canada, Heart and Stroke Foundation of Canada

OBJECTIVE

To provide updated, evidence-based recommendations concerning the effects of alcohol consumption on the prevention and control of hypertension in otherwise healthy adults (except pregnant women).

OPTIONS

There are 2 main options for those at risk for hypertension: avert the condition by limiting alcohol consumption or by using other nonpharmacologic methods, or maintain or increase the risk of hypertension by making no change in alcohol consumption. The options for those who already have hypertension include decreasing alcohol consumption or using another nonpharmacologic method to reduce hypertension; commencing, continuing or intensifying antihypertensive medication; or taking no action and remaining at increased risk of cardiovascular disease.

OUTCOMES

The health outcomes considered were changes in blood pressure and in morbidity and mortality rates. Because of insufficient evidence, no economic outcomes were considered.

EVIDENCE

A MEDLINE search was conducted for the period 1966-1996 with the terms ethyl alcohol and hypertension. Other relevant evidence was obtained from the reference lists of articles identified, from the personal files of the authors and through contacts with experts. The articles were reviewed, classified according to study design, and graded according to the level of evidence.

VALUES

A high value was placed on the avoidance of cardiovascular morbidity and premature death caused by untreated hypertension.

BENEFITS, HARMS AND COSTS

A reduction in alcohol consumption from more than 2 standard drinks per day reduces the blood pressure of both hypertensive and normotensive people. The lowest overall mortality rates in observational studies were associated with drinking habits that were within these guidelines. Side effects and costs were not measured in any of the studies.

RECOMMENDATIONS

(1) It is recommended that health care professionals determine how much alcohol their patients consume. (2) To reduce blood pressure in the population at large, it is recommended that alcohol consumption be in accordance with Canadian low-risk drinking guidelines (i.e., healthy adults who choose to drink should limit alcohol consumption to 2 or fewer standard drinks per day, with consumption not exceeding 14 standard drinks per week for men and 9 standard drinks per week for women). (3) Hypertensive patients should also be advised to limit alcohol consumption to the levels set out in the Canadian low-risk drinking guidelines.

VALIDATION

These recommendations are similar to those of the World Hypertension League, the National High Blood Pressure Education Program Working Group on Primary Prevention of Hypertension and the previous recommendations of the Canadian Coalition for High Blood Pressure Prevention and Control and the Canadian Hypertension Society. They have not been clinically tested. The low-risk drinking guidelines are those of the Addiction Research Foundation of Ontario and the Canadian Centre on Substance Abuse.

SPONSORS

The Canadian Hypertension Society, the Canadian Coalition for High Blood Pressure Prevention and Control, the Laboratory Centre for Disease Control at Health Canada, and the Heart and Stroke Foundation of Canada. The low-risk drinking guidelines have been endorsed by the College of Family Physicians of Canada and several provincial organizations.

Lifestyle modifications to prevent and control hypertension. 2. Recommendations on obesity and weight loss. Canadian Hypertension Society, Canadian Coalition for High Blood Pressure Prevention and Control, Laboratory Centre for Disease Control at Health Canada, Heart and Stroke Foundation of Canada

OBJECTIVE

To provide updated, evidence-based recommendations concerning the effects of weight loss and maintenance of healthy weight on the prevention and control of hypertension in otherwise healthy adults (except pregnant women).

OPTIONS

The main options are to attain and maintain a healthy body weight (body mass index [BMI] 20-25 kg/m2) or not to do so. For those at risk for hypertension, weight loss and maintenance of healthy weight may prevent the condition. For those who have hypertension, weight loss and maintenance of healthy weight may reduce or obviate the need for antihypertensive medications.

OUTCOMES

The health outcome considered was change in blood pressure. Because of insufficient evidence, no economic outcomes were considered.

EVIDENCE

A MEDLINE search was conducted for the years 1992-1996 with the terms hypertension and obesity in combination and antihypertensive therapy and obesity in combination. Other relevant evidence was obtained from the reference lists of the articles identified, from the personal files of the authors and through contacts with experts. The articles were reviewed, classified according to study design and graded according to level of evidence.

VALUES

A high value was placed on the avoidance of cardiovascular morbidity and premature death caused by untreated hypertension.

BENEFITS, HARMS AND COSTS

Weight loss and the maintenance of healthy body weight reduces the blood pressure of both hypertensive and normotensive people. The indirect benefits of a health body weight are well known. The negative effects of weight loss are primarily the frustrations associated with attaining and maintaining a healthy weight. The costs associated with weight loss programs were not measured in the studies reviewed.

RECOMMENDATIONS

(1) It is recommended that health care professionals determine weight (in kilograms), height (in metres) and BMI for all adults. (2) To reduce blood pressure in the population at large, it is recommended that Canadians attain and maintain a healthy BMI (20-25). (3) All overweight hypertensive patients (BMI greater than 25) should be advised to reduce their weight.

VALIDATION

These recommendations are similar to those of the World Hypertension League, the National High Blood Pressure Education Program Working Group on Primary Prevention of Hypertension, the Canadian Hypertension Society and the Canadian Coalition for High Blood Pressure Prevention and Control. They have not been clinically tested.

SPONSORS

The Canadian Hypertension Society, the Canadian Coalition for High Blood Pressure Prevention and Control, the Laboratory Centre for Disease Control at Health Canada, and the Heart and Stroke Foundation of Canada.

Lifestyle modifications to prevent and control hypertension. 1. Methods and an overview of the Canadian recommendations. Canadian Hypertension Society, Canadian Coalition for High Blood Pressure Prevention and Control, Laboratory Centre for Disease Control at Health Canada, Heart and Stroke Foundation of Canada

OBJECTIVE

To provide updated, evidence-based recommendations for health care professionals on lifestyle changes to prevent and control hypertension in otherwise healthy adults (except pregnant women).

OPTIONS

For people at risk for hypertension, there are a number of lifestyle options that may avert the condition--maintaining a healthy body weight, moderating consumption of alcohol, exercising, reducing sodium intake, altering intake of calcium, magnesium and potassium, and reducing stress. Following these options will maintain or reduce the risk of hypertension. For people who already have hypertension, the options for controlling the condition are lifestyle modification, antihypertensive medications or a combination of these options; with no treatment, these people remain at risk for the complications of hypertension.

OUTCOMES

The health outcomes considered were changes in blood pressure and in morbidity and mortality rates. Because of insufficient evidence, no economic outcomes were considered.

EVIDENCE

A MEDLINE search was conducted for the period January 1996 to September 1996 for each of the interventions studied. Reference lists were scanned, experts were polled, and the personal files of the authors were used to identify other studies. All relevant articles were reviewed, classified according to study design and graded according to level of evidence.

VALUES

A high value was placed on the avoidance of cardiovascular morbidity and premature death caused by untreated hypertension.

BENEFITS, HARMS AND COSTS

Lifestyle modification by means of weight loss (or maintenance of healthy body weight), regular exercise and low alcohol consumption will reduce the blood pressure of appropriately selected normotensive and hypertensive people. Sodium restriction and stress management will reduce the blood pressure of appropriately selected hypertensive patients. The side effects of these therapies are few, and the indirect benefits are well known. There are certainly costs associated with lifestyle modification, but they were not measured in the studies reviewed. Supplementing the diet with potassium, calcium and magnesium has not been associated with a clinically important reduction in blood pressure in people consuming a healthy diet.

RECOMMENDATIONS

(1) It is recommended that health care professionals determine the body mass index (weight in kilograms/[height in metres]2) and alcohol consumption of all adult patients and assess sodium consumption and stress levels in all hypertensive patients. (2) To reduce blood pressure in the population at large, it is recommended that Canadians attain and maintain a healthy body mass index. For those who choose to drink alcohol intake should be limited to 2 or fewer standard drinks per day (maximum of 14/week for men and 9/week for women). Adults should exercise regularly. (3) To reduce blood pressure in hypertensive patients, individualized therapy is recommended. This therapy should emphasize weight loss for overweight patients, abstinence from or moderation in alcohol intake, regular exercise, restriction of sodium intake and, in appropriate circumstances, individualized cognitive behaviour modification to reduce the negative effects of stress.

VALIDATION

The recommendations were reviewed by all of the sponsoring organizations and by participants in a satellite symposium of the fourth international Conference on Preventive Cardiology. They are similar to those of the World Hypertension League and the Joint National committee, with the exception of the recommendations on stress management, which are based on new information. They have not been clinically tested.

SPONSORS

The Canadian Hypertension Society, the Canadian Coalition for High Blood Pressure Prevention and Control, the Laboratory Centre for Disease Control at health Canada, and the Heart and Stroke Foundation of Canada.

Is usual measurement of blood pressure meaningful?

BACKGROUND

Standardized measurement of blood pressure is widely recommended but rarely applied in usual clinical practice.

OBJECTIVE

To determine the differences resulting from physicians using standardized and usual (casual) techniques for measurement of blood pressure.

METHODS

Blood pressures measured by a research nurse, ambulatory blood pressure monitoring and echocardiographic estimation of left ventricular mass index were used as standards for comparison.

RESULTS

Use of casual technique resulted in blood pressure readings higher than those obtained by standardized technique, namely 6.2 (3.1-9.3) systolic and 3.9 (2.4-5.4) diastolic mmHg [means (95% confidence intervals)], and readings that were more variable. Sixty-two patients (42%) were classified normotensive by standardized techniques but hypertensive by physicians casual technique. When standardized technique was used 22 patients (15%) were classified hypertensive but blood pressure readings in normal range were obtained by usual technique. Measurements obtained using standardized technique were less variable and were significantly correlated to left ventricular mass index.

CONCLUSION

Using standardized technique is important if one is to classify the blood pressures of patients correctly. Use of usual or casual technique results in higher, more variable readings that are not related to left ventricular mass index. Results of this study strongly support recommendations that standardized technique should be used for assessing the cardiovascular risk of all adult patients.

The effect of crossing legs on blood pressure: a randomized single-blind cross-over study

BACKGROUND

Although there is a theoretical basis for crossing legs to increase blood pressure, there are no published data addressing this question. As a result guidelines for measurement of blood pressure are not consistent in recommending that patients legs should not be crossed during measurement.

OBJECTIVE

To determine the effect of crossing legs on blood pressure.

METHODS

Fifty healthy volunteers and 53 patients with hypertension were randomly allocated in a study with a cross-over design to having seated blood pressure measured with their legs in three different positions: feet flat on the floor and legs crossed using two common methods. The blood pressures were assessed by an investigator who was blinded to the leg positions and used a fully automated sphygmomanometer.

RESULTS

Crossing legs during blood pressure measurement increased systolic (by average 8.1 mmHg, 95% confidence interval 5.1-11.1 mmHg for method 1; 10.5 mmHg, 6.5-14.6 mmHg for method 2) and diastolic (by 4.5 mmHg, 1.5-7.5 mmHg for method 1; 4.0 mmHg, 2.0-6.0 mmHg for method 2) blood pressures in patients who have hypertension. Crossing legs increased systolic blood pressure (by 2.5 mmHg, 1.3)3.8 mmHg for method 1; 2.3 mmHg, 0.9-3.7 mmHg for method 2) in the healthy volunteers but had little effect on diastolic blood pressure. The cardiovascular-risk class increased for a large number of the hypertensive patients but for fewer of the normotensive subjects.

CONCLUSIONS

Blood pressure increases when legs are crossed and this increases the estimation of cardiovascular risk for many patients. Care should be taken to ensure that the patients feet are flat on the floor when measuring their blood pressure.

Ferrous sulphate interacts with captopril

AIMS

To determine if iron binds strongly to captopril and reduces captopril absorption.

METHODS

A variety of in vitro experiments was conducted to examine iron binding to captopril and a randomized, double-blind, placebo controlled, cross-over study design was used to assess the in vivo interaction. Captopril (25 mg) was coingested with either ferrous sulphate (300 mg) or placebo by seven healthy adult volunteers. Subjects were phlebotomized and had blood pressure measured at 0, 0.25, 0.5, 1, 2, 4, 6, 8, and 12 h post ingestion. A 1 week washout period was used.

RESULTS

The coingestion of ferrous sulphate and captopril was associated with a 37% (134 ng ml(-1) h, 95% CI 41-228 ng ml(-1) h, P = 0.03) decrease in area under the curve (AUC) for unconjugated plasma captopril. There were no substantial changes in Cmax (mean difference; -32; 95% CI -124-62 ng ml(-1) (P = 0.57)) or in tmax (mean difference; 0; 95% CI -18-18 min (P = 0.65)) for unconjugated captopril when captopril was ingested with iron. There was a statistically insignificant increase in AUC for total plasma captopril of 43% (1312 ng ml(-1) h, 95% CI -827-3451 ng ml(-1) h P = 0.27) when captopril was ingested with iron. The addition of ferric chloride to captopril resulted in the initial rapid formation of a soluble blue complex which rapidly disappeared to be replaced by a white precipitant. The white precipitate was identified as captopril disulphide dimer. There were no significant differences in systolic and diastolic blood pressures between the treatment and placebo groups.

CONCLUSIONS

Co-administration of ferrous sulphate and iron results in decreased unconjugated captopril levels likely due to a chemical interaction between ferric ion and captopril in the gastrointestinal tract. Care is required when coprescribing captopril and iron salts.

Project Salsa: development and institutionalization of a nutritional health promotion project in a Latino community

PURPOSE

Project Salsa was a community-based effort seeking to promote health through nutritional behavior change in a Latino community of San Diego, California. The purpose of this article is to report on program factors related to long-term institutionalization of Project Salsa interventions.

DESIGN

Project Salsa was a demonstration rather than an experimental project. To ensure maximum sensitivity to the needs and values of the community, Project Salsa began with an extensive health needs assessment, including development of an advisory council, telephone survey, archival research, and key informant interviews.

SETTING

Project Salsa interventions took place in San Ysidro, California, located near the U.S.-Mexico border adjacent to Tijuana from 1987 to 1992.

SUBJECTS

The intervention community had 14,500 residents, of which nearly 83% were Latino.

INTERVENTIONS

Interventions included coronary heart disease risk factor screenings, meal preparation classes, newspaper columns, point-of-purchase education, school health and cafeteria programs, and breast-feeding promotion.

MEASURES

Institutionalization of intervention components.

RESULTS

Two of the interventions, the risk factor screenings and school health programs, are still in operation 4 years after the end of project funding.

CONCLUSIONS

Four factors common to institutionalized components are presented in the paper.

Folate status, vascular disease and cognition in elderly Canadians

OBJECTIVE

To report on the relationship between serum folate levels and the prevalence of stroke, peripheral vascular disease, cognitive problems and short-term mortality in elderly people.

SETTING AND PARTICIPANTS

1171 subjects whose serum folate was determined as part of their clinical examination in the Canadian Study of Health and Aging, a population study of individuals 65 years and older.

METHODS

Cross-sectional analysis compared relationships between serum folate levels and clinical features; longitudinal analysis examined mortality at follow-up by folate status at the time of the clinical examination.

RESULTS

Membership in the lowest quartile for serum folate was associated with an increased likelihood of stroke. Those with low folate levels were more likely to be demented, institutionalized and depressed. In the cognitively impaired but not demented group, those with low folate levels scored lower on the Modified Mini Mental State and had more short-term memory problems.

CONCLUSIONS

Low folate level was a significant explanatory variable for stroke. Low folate levels were common in all types of dementia and were associated with a history of weight loss, lower body mass index and lower serum albumin concentrations. This may reflect the reduced ability of cognitively impaired individuals to eat adequately.

Different effects of heparin in males and females

OBJECTIVE

To determine whether women have a Pharmacological predisposition to bleeding and a worse outcome than men during heparin therapy, in light of recent studies showing that women have a higher risk of bleeding complications following anticoagulant therapy for thrombotic disorders than men.

DESIGN

Prospectively planned subgroup analysis of a double-blind randomized study.

SETTING

Academic tertiary care hospitals in Hamilton, Ont.

PATIENTS

A total of 199 consecutive patients (105 women, 93 men) presenting with proximal deep vein thrombosis. (One patient was not included due to incomplete data).

OUTCOME MEASURES

Activated partial thromboplastin time (APTT) values and heparin levels were assessed every 4 to 6 hours after a standard heparin bolus and infusion. The effect of sex on heparin doses and levels was also assessed after stable therapeutic heparin infusions were achieved.

RESULTS

The women had higher heparin levels than the men (0.560 [standard error of the mean, SEM 0.056] units/mL v. 0.347 [SEM 0.062] units/mL, p < 0.0001) and higher APTT values (94.9 [SEM 0.50] seconds v. 81.2 [SEM 0.53] seconds, p = 0.0002) 4 to 6 hours after being given the same heparin bolus and infusion doses. After achieving therapeutic APTT values, the women received lower heparin doses than the men (27.9 [SEM 0.24] 1000 units/24 hours v. 34.5 [SEM 0.24] 1000 units/24 hours, p < 0.0001) but had higher heparin levels (0.349 [SEM 0.035] units/mL v. 0.292 [SEM 0.036] units/mL, p = 0.034). The effect of sex was also determined after correcting for the known effects of weight and age on heparin therapy. After adjusting for patient weight, among the women, older women had higher heparin levels but, among the men, there was little effect of age. There were no sex differences with respect to bleeding complications or recurrent thromboembolic disease.

CONCLUSION

Women showed alterations in the pharmacokinetics of heparin, which could explain a predisposition to bleeding complications. Under the heparin protocol used in this study, heparin doses were rapidly adjusted, which may explain why rates of bleeding complications and recurrent thromboembolism were similar in men and women. We do not recommend changes in heparin therapy based on these results, but suggest the use of protocols that assess coagulation parameters frequently and then adjust heparin doses rapidly, in order to individualize therapy. Further study is required to determine whether there are sex differences in bleeding complications associated with anticoagulant therapy, and to confirm the altered pharmacokinetics of heparin in women.

Influencing prescribing patterns

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