Public health burden of coronary heart disease risk factors among middle-aged and elderly men

Trends in Health Behavior Patterns Among U.S. Adults, 2003-2015

Background

Over the last two decades, considerable resources from U.S. federal and philanthropic entities were dedicated to improving preventive and reducing chronic disease risk behaviors.

Purpose

Given the population health efforts to improve health behaviors in adults, this study explored how health behavior patterns shifted over the years by exploring multiple health behavior patterns.

Methods

Data were obtained from the odd years between 2002 and 2016 Behavioral Risk Factor Surveillance System. Latent class analyses including fruit and vegetables, physical activity, cigarette smoking, and heavy and binge drinking were conducted for each year.

Results

Three-class models best fit the data and were most interpretable. Each year included Healthy or Physically Active (preventive behaviors, no risk behaviors), Apathetic (no preventive/risk behaviors), and Binge-drinking groups. Gender and age consistently distinguished the Healthy/Physically Active groups from the Apathetic and Binge-drinking groups across the years.

Conclusions

This study confirms health behavior clusters exist and have been stable across time. This is encouraging as trends have not gotten worse, but there is room for improvement. Repetition of the groups across years suggests that despite population-level interventions, a large segment of the U.S. population at risk for chronic diseases are not engaging in preventive health.

In silico thrombin generation: Plasma composition imbalance and mortality in human immunodeficiency virus

Background

Effective HIV treatment with antiretroviral therapy has prolonged survival and shifted causes of death to non-AIDS illnesses such as cardiovascular disease. We have shown that inflammation and HIV viral load associate with pro- and anticoagulant factor imbalances resulting in increased thrombin generation when mathematically modeled. We explore the hypothesis that factor compositional imbalance, corresponding to increased in silico thrombin generation, predicts mortality among HIV+ persons.

Methods

In a nested case-control study of HIV+ individuals on continuous antiretroviral therapy in two large trials, we evaluated cases (any non-violent mortality, n = 114) and matched controls (n = 318). Thrombin generation in response to a tissue-factor initiator for each individual was calculated by a mathematical model incorporating levels of factors (F)II, V, VII, VIII, IX, X, antithrombin, tissue factor pathway inhibitor, and protein C (PC) measured at study entry to the trials. In silico thrombin generation metrics included clot time, maximum rate (MaxR), maximum level (MaxL), and area under the curve (AUC).

Results

Levels of antithrombin and PC decreased, while FV and FVIII were higher in cases vs controls. This resulted in a more procoagulant phenotype with increased MaxR, MaxL, and AUC in cases compared to controls (P < 0.05 for all).

Conclusions

Antithrombin, FV, FVIII, and PC were the major contributors to the increased thrombin generation associated with mortality risk. Our results suggest that mortality in HIV is associated with an increase in in silico thrombin generation via altered balance of pro- and anticoagulant factors, likely due to an inflammatory response signal, and resulting coagulopathy.

Physical Activity and Heart Failure: Taking Steps to Control a Major Public Health Burden

Heart failure (HF) is a complex clinical syndrome that is increasingly prevalent among US adults and accounts for substantial burden of healthcare costs and morbidity. HF is commonly associated with prior myocardial infarction as well as prolonged exposure to hypertension, diabetes, and coronary atherosclerosis. Exercise training is becoming established in the management of HF because of its beneficial effect on both central (cardiac) and peripheral (skeletal muscle) HF mechanisms. The role of habitual physical activity in the primary prevention of HF is less clear. Recent prospective observational studies suggest there is lower risk of developing HF in adults who are more physically activity and have higher cardiorespiratory fitness compared with their less active and fit peers. This article reviews the published evidence on physical activity and HF prevention, discusses potential mechanisms for this benefit, and suggests areas where further research is needed to establish recommendations on the type, amount, and intensity of physical activity required to prevent occurrence of HF.

Similarities and differences between coronary heart disease and stroke in the associations with cardiovascular risk factors: The Japan Collaborative Cohort Study

BACKGROUND AND AIMS

Coronary heart disease (CHD) and stroke have common risk factors, but some of these differ in the magnitude or direction of associations between CHD and stroke. We assessed whether the impact of each risk factor differed between CHD and stroke mortality in Asians.

METHODS

In total, 104 910 subjects aged 40-79 years without histories of cancer, CHD and stroke at baseline were followed between 1988 and 2009. Competing-risks analysis was used to test for differences in the associations of each risk factor with two endpoints (CHD and stroke). Population attributable fractions (PAFs) were also calculated for these endpoints to estimate the population impact of each risk factor.

RESULTS

During a median 19.1-year follow-up, 1554 died from CHD and 3163 from stroke. The association of hypertension with CHD was similar to that with stroke in terms of the magnitude and direction (multivariable-adjusted hazard ratio for CHD: 1.63 vs. stroke: 1.73 in men and 1.70 vs. 1.66 in women). Conversely, the magnitude of these associations differed for smoking (CHD: 1.95 vs. stroke: 1.23 in men and 2.45 vs. 1.35 in women) and diabetes (1.49 vs. 1.09 in men and 2.08 vs. 1.39 in women). The highest PAF for CHD was caused by smoking in men and by hypertension in women; that for stroke was caused by hypertension in both sexes.

CONCLUSIONS

Hypertension associations and PAFs were consistent between CHD and stroke, but not for other risk factors. These findings may be useful to optimize public health intervention strategies.

Social capital, mortality, cardiovascular events and cancer: a systematic review of prospective studies

BACKGROUND

Social capital is considered to be an important determinant of life expectancy and cardiovascular health. Evidence on the association between social capital and all-cause mortality, cardiovascular disease (CVD) and cancer was systematically reviewed.

METHODS

Prospective studies examining the association of social capital with these outcomes were systematically sought in Medline, Embase and PsycInfo, all from inception to 8 October 2012. We categorized the findings from studies according to seven dimensions of social capital, including social participation, social network, civic participation,social support, trust, norm of reciprocity and sense of community, and pooled the estimates across studies to obtain summary relative risks of the health outcomes for each social capital dimension. We excluded studies focusing on children, refugees or immigrants and studies conducted in the former Soviet Union.

RESULTS

Fourteen prospective studies were identified. The pooled estimates showed no association between most social capital dimensions and all-cause mortality, CVD or cancer. Limited evidence was found for association of increased mortality with social participation and civic participation when comparing the most extreme risk comparisons.

CONCLUSIONS

Evidence to support an association between social capital and health outcomes is limited. Lack of consensus on measurements for social capital hinders the comparability of studies and weakens the evidence base.

Examining physician counselling to promote the adoption of physical activity

BACKGROUND

While the benefits of physical activity are generally recognized, over half of adult Canadians are not active enough to receive those benefits. Physicians may influence patient activity through counselling; however, research is inconsistent regarding their effectiveness in doing so. Increasing patients' use of self-regulatory skills in managing their activity and additional telephone support are suggested as two means of improving physician counselling. When assessing the effectiveness of physician counselling, it may be important to measure both outcome and treatment adherence. We compared physician-directed activity counselling (modified PACE protocol) with a modified PACE protocol augmented with telephone-based counselling for patient support for both outcome and treatment adherence.

METHODS

Physicians counselled 90 patients using a modified PACE protocol that included self-regulatory skills. Physical activity was assessed by questionnaire at baseline (prior to counselling) and one month later. Participants were divided into two groups: counselling (modified PACE counselling) and enhanced counselling (modified PACE counselling plus telephone support).

RESULTS

The main outcome (mean energy expenditure) and secondary outcomes of treatment adherence (frequency, frequency of moderate activity, and duration) significantly increased over time (p < 0.05). No significant interactions between group and time were found.

INTERPRETATION

Our results support the effectiveness of physician counselling for activity that included the use of self-regulation skills. The effectiveness of telephone support over and above that of physician counselling was not supported. Our results demonstrate that assessing treatment adherence provides a means of discerning whether the counselling intervention was delivered as intended.

Seasonal variation in leisure-time physical activity among Canadians

BACKGROUND

Cardiovascular disease (CVD) mortality is higher in winter than summer, particularly in cold climates. Physical activity reduces CVD risk but climate impacts participation in physical activity. Canada has substantial climatic variation but its relation with physical activity is understudied. In this investigation, we evaluated the relation between seasonality and physical activity among Canadians.

METHODS

We used public domain data from the Canadian Community Health Survey, Cycle 2.2 (CCHS 2.2), a representative, cross-sectional sample of free-living Canadians in 2004. Leisure-time physical activity was measured using a modified version of the Physical Activity Monitor that was validated. Season was determined by the time of the interview, i.e., Winter: January 1 to March 31, Spring: April 1 to June 30, Summer: July 1 to September 30, and Fall: October 1 to December 31. In all multivariate models, we adjusted for age, sex, education, and income adequacy.

RESULTS

There were 20,197 persons aged 19 years and older in this analysis. In the winter, 64% of Canadians were inactive as compared with 49% in the summer. Total average daily energy expenditure was 31.0% higher in summer than winter after multivariate adjustment. Leisure-time physical activity was 86% more likely in the summer than winter (multivariate OR = 1.86, 95% CI 1.40, 2.45). The relation between seasonality and physical activity was weakest in Newfoundland and Labrador and stronger in Saskatchewan and British Columbia (p-value for interaction = 0.02).

INTERPRETATION

Seasonality impacts physical activity patterns in Canada and varies across the provinces. This needs to be considered in physical activity programming.

Lipid Management and the Elderly

Advancing age is an independent risk factor for the development of coronary heart disease. However, the significance of hypercholesterolemia as a cardiovascular risk factor in the elderly, has been widely debated. While no large-scale, randomized clinical trial has been conducted to evaluate cholesterol lowering solely in the elderly, evidence from older subgroups in several intervention trials supports the efficacy of lowering elevated low-density lipoprotein cholesterol for reducing cardiovascular risk in the elderly. Furthermore, although the relative risk of hyper-cholesterolemia for coronary heart disease incidence may be attenuated with advancing age, the population-wide impact of treating elevated cholesterol levels in the elderly would be large, due to the high frequency of coronary heart disease in the elderly. This article reviews key issues in the management of hyper-cholesterolemia with respect to coronary heart disease risk reduction in the elderly.

Cost utility analysis of physical activity counselling in general practice

OBJECTIVE

To evaluate the economic performance of the 'Green Prescription' physical activity counselling program in general practice.

METHODS

Cost utility analysis using a Markov model was used to estimate the cost utility of the Green Prescription program over full life expectancy. Program effectiveness was based on published trial data (878 inactive patients presenting to NZ general practice). Costs were based on detailed costing information and were discounted at 5% per anum. The main outcome measure is cost per quality adjusted life year (QALY) gained. Extensive one-way sensitivity analyses were performed along with probabilistic (stochastic) analysis.

RESULTS

Incremental, modelled cost utility of the Green Prescription program compared with 'usual care' was dollar NZ2,053 per QALY gained over full life expectancy (range dollar NZ827 to dollar NZ37,516 per QALY). Based on the probabilistic sensitivity analysis, 90% of ICERs fell below dollar NZ7,500 per QALY.

CONCLUSIONS

Based on a plausible and conservative set of assumptions, if decision makers are willing to pay at least dollar NZ2,000 per QALY gained the Green Prescription program is likely to represent better value for money than 'usual care'.

IMPLICATIONS

The Green Prescription program performs well, representing a good buy relative to other published cost effectiveness estimates. Policy makers should consider encouraging general practitioners to prescribe physical activity advice in the primary care setting, in association with support from exercise specialists.

Thrombin generation profiles in deep venous thrombosis

BACKGROUND

Reliable markers and methods to predict risk for thrombosis are essential to clinical management.

OBJECTIVE

Using an integrated approach that defines an individual's comprehensive coagulation phenotype might prove valuable in identifying individuals at risk for experiencing a thrombotic event.

METHODS

Using a numerical simulation model, we generated tissue factor (TF) initiated thrombin curves using coagulation factor levels from the Leiden Thrombophilia Study population and evaluated thrombotic risk, by sex, age, smoking, alcohol consumption, body mass index (BMI) and oral contraceptive (OC) use. We quantitated the initiation, propagation and termination phases of each individuals' comprehensive TF-initiated thrombin generation curve by the parameters: time to 10 nm of thrombin, maximum time, level and rate (MaxR) of thrombin generated and total thrombin.

RESULTS

The greatest risk association was obtained using MaxR; with a 2.6-fold increased risk at MaxR exceeding the 90th percentile. The odds ratio (OR) for MaxR was 3.9 in men, 2.1 in women, and 2.9 in women on OCs. The association of risk with thrombin generation did not differ by age (OR:2.8 OR:2.5), BMI (OR:2.9 OR:2.3) or alcohol use. In both numerical simulations and empirical synthetic plasma, OC use created extreme shifts in thrombin generation in both control women and women with a prior thrombosis, with a larger shift in thrombin generation in control women. This suggests an interaction of OC use with underlying prothrombotic abnormalities.

CONCLUSIONS

Thrombin generation based upon the individual's blood composition is associated with the risk for thrombosis and may be useful as a predictive marker for evaluating thrombosis on an individual basis.

The plasma hemostatic proteome: thrombin generation in healthy individuals

BACKGROUND AND OBJECTIVES

The range of plasma concentrations of hemostatic analytes in the population is wide. In this study these components of blood coagulation phenotype are integrated in an attempt to predict clinical risk.

METHODS

We modeled tissue factor (TF)-induced thrombin generation in the control population (N = 473) from the Leiden Thrombophilia Study utilizing a numerical simulation model. Hypothetical thrombin generation curves were established by modeling pro- and anticoagulant factor levels for each individual. These curves were evaluated using parameters which describe the initiation, propagation and termination phases of thrombin generation, i.e. time to 10 nm thrombin (approximate clot time), total thrombin and the maximum rates and levels of thrombin generated.

RESULTS AND CONCLUSIONS

The time to 10 nm thrombin varied over a 3-fold range (2.9-9.5 min), maximum levels varied over a approximately 4-fold range (200-800 nm), maximum rates varied approximately 4.8-fold (90-435 nm min(-1)) and total thrombin varied approximately 4.5-fold (39-177 microm s(-1)) within this control population. Thrombin generation curves, defined by the clotting factor concentrations, were distinguished by sex, age, alcohol consumption, body mass index (BMI) and oral contraceptive (OC) use (OC > sex > BMI > age). Our results show that the capacity for thrombin generation in response to a TF challenge may represent a method to identify an individual's propensity for developing thrombosis.

Weight reduction is not a major reason for improvement in rheumatoid arthritis from lacto-vegetarian, vegan or Mediterranean diets

Objectives

Several investigators have reported that clinical improvements of patients with rheumatoid arthritis (RA), from participating in therapeutic diet intervention studies, have been accompanied by loss of body weight. This has raised the question whether weight reduction per se can improve RA. In order to test this hypothesis, three previously conducted diet intervention studies, comprising 95 patients with RA, were pooled. Together with Age, Gender, and Disease Duration, change during the test period in body weight, characterised dichotomously as reduction or no reduction (dichoΔBody Weight), as well as Diet (dichotomously as ordinary diet or test diet), were the independent variables. Dependent variables were the difference (Δ) from baseline to conclusion of the study in five different disease outcome measures. ΔESR and ΔPain Score were both characterised numerically and dichotomously (improvement or no improvement). ΔAcute Phase Response, ΔPhysical Function, and ΔTender Joint Count were characterised dichotomously only. Multiple logistic regression was used to analyse associations between the independent and the disease outcome variables.

Results

Statistically significant correlations were found between Diet and three disease outcome variables i.e. ΔAcute-Phase Response, ΔPain Score, and ΔPhysical Function. Δ Body Weight was univariately only correlated to ΔAcute-Phase Response but not significant when diet was taken into account.

Conclusion

Body weight reduction did not significantly contribute to the improvement in rheumatoid arthritis when eating lacto-vegetarian, vegan or Mediterranean diets.

The kaiser permanente northwest cardiovascular risk factor management program: a model for all

Proof of the effectiveness of preventive measures that reduce established risk traits for atherothrombotic disorders has spurred attempts to systematically apply these interventions among susceptible populations. One such attempt is the Cardiovascular Risk Factor Management (CVRFM) Program, launched in 2003 to optimize clinical management and outcomes for 75,000 Kaiser Permanente Northwest Region (KPNW) members with atherosclerotic cardiovascular disease (CVD) or hypertension. The CVRFM Program is a centralized, multidisciplinary, proactive telephone-based clinical management intervention consisting of an "outreach" call, an interview, a mailed individualized care plan and information packet, regular follow-up (including protocolized medication management) and-when "goal status" is achieved-transfer of the patient to a maintenance plan.Quarterly evaluation of effectiveness entailed measurement of a range of clinical, utilization, and member satisfaction outcomes. Results by the fourth quarter were outstanding: For example, >98% of participants with coronary disease or diabetes had LDL cholesterol testing, >90% of coronary patients received aspirin or statin treatment, 99% were "extremely" or "very" satisfied with the program, and reductions were observed in the number of hospitalizations and visits to the emergency department and clinic. Mathematical models predict a decrease in myocardial infarctions and cardiovascular mortality within two years after implementing the program, the underlying principles of which should yield similar improvement in other Kaiser Permanente (KP) Regions and in other health care organizations.

Cardiovascular disease: application of a composite risk index from the Telehealth System in a district community

Assessing a combination of cardiovascular disease (CVD)-risk factors may be a practical tool for risk assessment and for finding the high-risk group among local community members. This study examines the association between the number of CVD-risk factors, regardless of any specific combination with the CVD ambit, using data from 1,570 residents in Tsing Yi community (Hong Kong) who registered with the Telehealth System. A quantitative composite CVD Risk Index (CVDRI) with scores ranging from 0 to 6 included rankings for high systolic and diastolic blood pressure, presence of diabetes, body mass index (BMI), smoking, and age. Multivariate logistic regression was used to estimate odds ratios for the prevalence of CVD. Those with a CVDRI of 1, 2, or 3 and above were 1.7 [95% confidence interval (CI) = 1.34-3.99], 5.3 (95% CI = 3.60-7.90), and 10 times (95% CI = 6.41-15.50) more likely to have CVD, respectively, than those with a risk index of 0. Among the CVDRI components, high blood pressure had the greatest influence on CVD risk, followed by presence of diabetes and high BMI. In conclusion, a CVDRI based on existing health data from a Telehealth System was developed and used to identify local community members at risk of CVD. Nurse intervention may achieve greater reduction of CVD morbidity and mortality if multiple risk factors for the high-risk group are addressed at the same time.

State of the science for care of older adults with heart disease

This article provided an overview of the current state of knowledge related to cardiovascular disease in elders. Some depth has been provided related to CHD and HF, two common diagnoses in older persons. The most striking finding is that although trials are increasingly including older cohorts of patients, research specifically testing known therapies in older patients is essential. In particular, research testing the safety, efficacy, and acceptability of therapies in the oldest old is greatly needed.

Relative risk of mortality in the physically inactive is underestimated because of real changes in exposure level during follow-up

Relative risk among exposure groups in prospective cohort studies is based on the assumption that all subjects are exposed at the level recorded at baseline throughout the study. Changes in risk behavior during follow-up will dilute the relative risk. This prospective cohort study in Copenhagen, Denmark, between 1964 and 1994 included 30,640 men and women; 19,149 were examined twice, with an interval of 6.7 (standard deviation, 3.4) years. Relative risks calculated from baseline measurements for moderately active and sedentary groups compared with the highly active group were 1.11 (95% confidence interval: 1.05, 1.18) and 1.64 (95% confidence interval: 1.53, 1.75), respectively. The relative risk between the highly active group and the sedentary group decreased with increasing follow-up time. When intraindividual changes in physical activity level during follow-up were taken into account, the relative risk of physical inactivity was 24-59% higher compared with the relative risk estimated from baseline measurements. The risk of a sedentary lifestyle is underestimated when it is calculated from one baseline measurement in prospective studies, because subjects change behavior during follow-up.

Hydralazine as antihypertensive therapy in obesity-related hypertension

OBJECTIVE

The objectives were two-fold: (1) determine whether the use of hydralazine as antihypertensive therapy during obesity development exacerbated obesity-related cardioacceleration and hormonal abnormalities; (2) determine whether the absence of hypertension in obesity attenuated obesity-related abnormalities in hemodynamics, cardiac hypertrophy, and hormonal profile.

DESIGN

Female New Zealand White rabbits were divided into lean control (n=12), lean hydralazine-treated (n=9), obese control (n=11), and obese hydralazine-treated (n=8) groups. Pretreatment mean blood pressure (BP) and heart rate (HR) were determined using telemetry. Pretreatment BP was maintained during 12 weeks of obesity development using hydralazine.

MEASUREMENTS

Chronically measured BP and HR; plasma/blood volume; wet and dry ventricular weights; body fat/water; and hormonal profile (plasma renin activity, aldosterone, cortisol, atrial natriuretic peptide, adrenaline, and noradrenaline).

RESULTS

Hydralazine treatment in obese animals attenuated obesity-related renin-angiotensin system (RAS) activation. In contrast, RAS was activated in lean hydralazine, as indicated by increased plasma aldosterone. The absence of hypertension in obese hydralazine did not result in attenuation of cardioacceleration, cardiac hypertrophy, or intravascular volumes.

CONCLUSIONS

Hydralazine treatment in obese rabbits did not exacerbate obesity-related cardiovascular and hormonal alterations. Cardioacceleration and cardiac hypertrophy persisted in obese hydralazine despite BP control, suggesting hypertension-independent effects of obesity on these variables. Hydralazine's effects on RAS activation differed in lean and obese rabbits, suggesting that the systemic effects of hydralazine as a control therapy in evaluation of antihypertensive medications may differ depending on the underlying pathology.

SCOPE: SCripture Oriented Preventive Education

BACKGROUND

Counseling to effect lasting change in health behaviors has proven only moderately effective. The Torah, or Five Books of Moses, conveys many of the key messages regularly promulgated by prevention professionals. The promise of synergy with the behavioral messages of preventive medicine among devout Scripture-based adherents led to the development of a SCripture Oriented Preventive Education (SCOPE) tool.

METHODS

Forty-eight SCOPE articles were written to complement the weekly Torah portion read throughout the year in Orthodox Jewish synagogues. These were disseminated via newsletter within a modern Orthodox Jewish community in Israel. Two articles are included. An age-stratified, 25% random sample (120/471) of community readership was surveyed to ascertain receptivity to SCOPE and to gauge support for future implementation.

RESULTS

Response rate was 76% (92/120). Lifestyle behavior-related articles were most popular (77% found them interesting) and injury prevention the least (41%). Knowledge gained was the most common benefit reported (55% of respondents), followed by attitude change (24%). Those aged 30 to 49 years were significantly more likely than others to report behavior change (p=0.002) and health improvement (p=0.005) secondary to SCOPE. Clinical prevention (p=0.007) and environmental health (p=0.03) articles were significantly more popular in people aged > or =30 and 30 to 49, respectively. Between 69% and 84% supported the implementation of SCOPE in secondary schools, by physicians, and/or rabbis.

CONCLUSIONS

SCOPE was designed to deliver prevention materials to faith communities via a Scripture-based vehicle. A postexposure readership survey in an Israeli Orthodox Jewish community demonstrated its effectiveness. SCOPE's ultimate utility as a counseling adjunct in Scripture-adherent communities awaits broader assessment.

Smoking and Aging Clinical Implications Part I: Health and Consequence

Smoking is the number one preventable cause of disability and mortality in older adults. In the past few decades there has been an enhanced focus on smoking behaviors and smoking cessation, however, the older smoker has been excluded. Even though nonsmoking status can provide older smokers with a chance for increased quality as well as quantity of life, they are asked less often to quit, given fewer resources, and provided less guidance than younger smokers. There is limited knowledge about how to design and deliver interventions for smoking cessation among older adults. The explanation for the absence of an empirical and clinical focus on smoking cessation for the older adult is in part because of the belief in myths rather than reality. These beliefs about the health consequences of smoking behaviors and the benefits of smoking cessation for older smokers are held by older adults and their health care providers. However, the truth is that older adults can stop smoking, and the benefits are vast.

The economics of smoking and cardiovascular disease

The direct medical cost of cardiovascular and circulatory diseases was $151 billion in 1995, approximately 17% of all direct medical care costs in the United States. Incidence and prevalence based estimates indicate that smoking is a major contributing factor for cardiovascular disease and associated costs. Statewide smoking control programs and workplace and public area smoking bans are effective in reducing smoking prevalence. Smoking cessation therapies are very cost-effective interventions for the prevention of cardiovascular disease. Incidence based estimates indicate that smoking cessation control expenditures in the United States have been a cost effective method for reducing the direct medical costs of cardiovascular disease in the past, and may be cost saving in the future. The expected cost of producing an additional ex-smoker has been estimated to be approximately $1,000 to $1,500. Most or all of this cost can be recovered in the short run from savings in avoided heart attacks and strokes alone in healthy quitters. Observational studies of the direct medical costs following cessation in those observed to quit show a reduction utilization, but which may occur only after a lag of three to five years.

Exercise and the transtheoretical model: a longitudinal test of a population sample

BACKGROUND

The purpose of this study was to test the ability of the Transtheoretical Model (TTM) to predict exercise stage transition of individuals in a large, untreated-population-based, random sample of Canadian adults (18-65 years of age) over two consecutive time periods.

METHODS

Assessments of TTM's stage of exercise behavior change, self-efficacy, pros, cons, experiential processes, and behavioral processes were made at baseline (time 1), 6 months (time 2), and 1 year (time 3). Six hundred eighty-three men and women, identified through random-digit telephone dialing, completed all measures across the three time points. Within each time period (time 1-2; time 2-3) participants were categorized as having regressed (moved back at least on stage), remained (no stage change), or progressed (moved forward at least one stage). Baseline TTM constructs were analyzed for their ability to predict change transition across the two time periods.

RESULTS

Of 40 possible predictions (20 for each time period) 18 (45%) were supported.

CONCLUSIONS

Overall, the findings demonstrate partial support for the internal validation of TTM in the exercise domain. Implications of the findings are discussed and future directions for researchers, practitioners, and program planners are provided.

Health benefits of physical activity with special reference to interaction with diet

Regular physical activity causes numerous and substantial performance-improving and health-enhancing effects. Most of them are highly predictable, dose-dependent and generalizable to a wide range of population groups. Many of the biological effects of regular, moderate physical activity translate into substantially reduced risk of coronary heart disease, cerebrovascular disease, hypertension, maturity onset diabetes, overweight and obesity, and osteoporosis. These effects also substantially reduce the risk of deterioration of functional capacity. In the genesis of these conditions, a lack of physical activity and inadequate nutrition act synergistically and in part additively, and they operate largely through the same pathways. It is conceivable to suggest that the prevalence of, e.g, the above mentioned metabolic diseases is so high in Europe largely because of the high prevalence of sedentariness and inadequate nutrition. Thus, both physical activity and nutrition have to be given strong emphasis in policies, strategies and programmes that will be developed and implemented for improving the health of Europeans.

A multibehavioral intervention to decrease cardiovascular disease risk factors in older men

The purpose of this study was to compare the effectiveness of two mutibehavioral interventions: stress management (SM) (nutrition, exercise, and stress management) and education (ED) (nutrition, exercise, and education) on reduction of cardiovascular disease (CVD) risk factors in older men. A convenience sample (n = 33) of older men (66 +/- 5 years) with at least one CVD risk factor participated in this 6-month intervention. Mean receiving the SM intervention (n = 25) exercised at the facility twice weekly (at > or = 70% maximum heart rate for 40 minutes) and received 12 hours each of nutrition and stress management class instruction. Men receiving the ED intervention (n = 8) received the same exercise and nutrition protocols but received 12 hours of education without stress management. There were no significant differences in body habitus, metabolic response, exercise endurance, blood pressure, or heart rate between groups at baseline. The SM group had significant pre-post differences in weight, body mass index, intraabdominal fat, subcutaneous fat, total cholesterol, low-density lipoprotein, triglycerides, VO2, supine systolic and diastolic blood pressures. The ED group demonstrated significant pre-post differences only in supine diastolic blood pressure. There were significant change score differences between the groups in triglycerides, subcutaneous fat, VO2, and body mass index. Results suggest that a 6-month multibehavioral intervention with stress management is effective in decreasing CVD risk factors in older men.

Pharmacoeconomic considerations in the management of hypertension

Hypertension is highly prevalent in developed and developing countries (more than 30% of the adult population when a threshold value of 140/90 mm Hg is selected). It constitutes one of the major cardiovascular risk factors and accounts for more than 5% of total deaths worldwide. The economic impact of hypertension is enormous, representing $US23.74 billion in the US in 1995 and approximately $US1685 million in Spain in 1994. Direct costs amount to more than 50% of the total costs of hypertension, and almost 70% of these are attributable to drug treatment. Furthermore, hypertensive patients use medical services 50% more than normotensive individuals, and hypertension represents one of the 3 leading causes of visits to primary healthcare centres. When considering the cost effectiveness of hypertension treatment, there is no doubt that it is cost effective in comparison with other interventions, although some controversies exist, mainly with respect to mild-to-moderate hypertension and to the long term versus short term benefits. The controversy about the absolute risk of hypertension influences the cost-effectiveness analysis. Because of the limitations of the available cost-effectiveness analyses, it is currently impossible to recommend the use of any particular antihypertensive drug for all patients with hypertension. Consequently, the choice of antihypertensive in any patient should be guided by clinical experience and the recommendations of the present international guidelines.

Waging war on modern chronic diseases: primary prevention through exercise biology

In this review, we develop a blueprint for exercise biology research in the new millennium. The first part of our plan provides statistics to support the contention that there has been an epidemic emergence of modern chronic diseases in the latter part of the 20th century. The health care costs of these conditions were almost two-thirds of a trillion dollars and affected 90 million Americans in 1990. We estimate that these costs are now approaching $1 trillion and stand to further dramatically increase as the baby boom generation ages. We discuss the reaction of the biomedical establishment to this epidemic, which has primarily been to apply modern technologies to stabilize overt clinical problems (e.g., secondary and tertiary prevention). Because this approach has been largely unsuccessful in reversing the epidemic, we argue that more emphasis must be placed on novel approaches such as primary prevention, which requires attacking the environmental roots of these conditions. In this respect, a strong association exists between the increase in physical inactivity and the emergence of modern chronic diseases in 20th century industrialized societies. Approximately 250,000 deaths per year in the United States are premature due to physical inactivity. Epidemiological data have established that physical inactivity increases the incidence of at least 17 unhealthy conditions, almost all of which are chronic diseases or considered risk factors for chronic diseases. Therefore, as part of this review, we present the concept that the human genome evolved within an environment of high physical activity. Accordingly, we propose that exercise biologists do not study "the effect of physical activity" but in reality study the effect of reintroducing exercise into an unhealthy sedentary population that is genetically programmed to expect physical activity. On the basis of healthy gene function, exercise research should thus be viewed from a nontraditional perspective in that the "control" group should actually be taken from a physically active population and not from a sedentary population with its predisposition to modern chronic diseases. We provide exciting examples of exercise biology research that is elucidating the underlying mechanisms by which physical inactivity may predispose individuals to chronic disease conditions, such as mechanisms contributing to insulin resistance and decreased skeletal muscle lipoprotein lipase activity. Some findings have been surprising and remarkable in that novel signaling mechanisms have been discovered that vary with the type and level of physical activity/inactivity at multiple levels of gene expression. Because this area of research is underfunded despite its high impact, the final part of our blueprint for the next millennium calls for the National Institutes of Health (NIH) to establish a major initiative devoted to the study of the biology of the primary prevention of modern chronic diseases. We justify this in several ways, including the following estimate: if the percentage of all US morbidity and mortality statistics attributed to the combination of physical inactivity and inappropriate diet were applied as a percentage of the NIH's total operating budget, the resulting funds would equal the budgets of two full institutes at the NIH! Furthermore, the fiscal support of studies elucidating the scientific foundation(s) targeted by primary prevention strategies in other public health efforts has resulted in an increased efficacy of the overall prevention effort. We estimate that physical inactivity impacts 80-90% of the 24 integrated review group (IRG) topics proposed by the NIH's Panel on Scientific Boundaries for Review, which is currently directing a major restructuring of the NIH's scientific funding system. Unfortunately, the primary prevention of chronic disease and the investigation of physical activity/inactivity and/or exercise are not mentioned in the almost 200 total subtopics comprising t

The sources of risk factor information for general practitioners: is physical activity under-recognised?

OBJECTIVE

To identify and compare the amount of material on physical activity and the management of smoking, hypertension and hypercholesterolaemia in medical journals and magazines frequently read by general practitioners.

METHOD

Qualitative study assessing the total number of articles and advertisements to which Australian GPs are exposed in journals and medical magazines they are likely to read.

RESULTS

Only 6% of articles about cardiovascular disease (CVD) risk factors in the Medline search and 5% in the medical magazine search discussed exercise prescription or how to start and maintain an exercise program. Most CVD risk factor articles were on the pharmacological treatment of hypertension (42%), followed by hypercholesterolaemia (32%) and smoking cessation (20%). A review of medical magazines found similarly ranked results, and a count of advertisements indicated 67% related to hypertension, 26% to hypercholesterolaemia and 7% to smoking cessation.

CONCLUSIONS

GPs are less well informed by the medical media about physical activity than about other traditional CVD risk factors, although the epidemiological evidence for their health benefits is similar. Strategies should be developed to inform doctors about the evidence of benefits from regular moderate physical activity, and for GPs to recommend exercise in most clinical encounters.