Prevention of Cardiovascular Risk Factors in the First Place

Cardiovascular disease (CVD) prevention can address the major risk factors—blood lipids, blood pressure, and smoking—and their determinants throughout the lifespan, with approaches varying according to age and risk. The Task Force on Research in Epidemiology and Prevention of Cardiovascular Diseases gave new impetus to the concept of early intervention: Their highest priority in CVD prevention was “to prevent the development of CVD risk in the first place.” Six issues follow: (1) the relation between “primordial prevention” of CVD and “prevention of the risk factors in the first place”; (2) the place of youth in context with older and younger age groups; (3) the importance of bridging institutional gaps between youth and adulthood; (4) the need to strengthen the scientific base linking the major risk factors (e.g., blood cholesterol concentration) with their determinants; (5) the value of rate of change in risk factors with age, and not only incidence of “treatable” levels of risk factors, as an outcome in assessing interventions; and (6) the role and appropriate design strategies for both observational and intervention studies. It is time for a radical expansion of our investment in preventing the risk factors in the first place.     

Human Adaptation to the Parasitic Environment

Man, in contact with the pathogens in his environment, responds by developing immunity with or without symptomatic illness. The incidence of infectious disease in a community depends on the parasitic factor or “infection pressure,” and the host factor, “herd immunity,” i.e., the resistance of the community as a whole to the infection. Environment is only a secondary factor which alters the relative values of the two primary factors. Morbidity varies directly as the “infection pressure,” and inversely as the “herd immunity.” The great difficulty heretofore has been to separate the two factors expressing morbidity. In diphtheria, to some extent, this is now possible by means of the Schick test. By using clues gained from the study of diphtheria, and examining the age-incidence, severity, and fatality, of other infections under various environmental conditions, the hypothesis is reached that herd-immunity increases with the herd''s past experience of the bacterial causes of most, if not all, infectious diseases. This immunity may be acquired latently, without illness, and, even if not always enough to prevent symptomatic infection, may be such that severity and fatality are decreased. The process is an example of the general biological mechanism by which the members of a species acquire adaptative variations more suitable to the environment. Of recent years air-borne droplet infections have caused less fatality and trouble to the English herd than a century ago. The manifold increase of the density and of the motion in the English herd must have greatly raised the average infection-pressure, but since severity of clinical disease has diminished and incidence has not increased in proportion, the herd-immunity of the English must have outstripped the increase of infection-pressure, i.e., the herd has become more closely adapted to its bacterial environment. It must not, however, be forgotten that adaptive fluctuations in parasitic characters must also play some part in all the phenomena of infectious disease.     

Primordial Prevention of Cardiovascular Disease through Applied Genetics

Primordial prevention might be considered prevention of the development of disease at its earliest stages or early intervention on risk factors to eliminate increased risk in the first place. In this review we consider how knowledge of genetic causes of early cardiovascular disease can lead to directed screening and better treatment of high risk individuals. While gene therapy would be the most “primordial” approach to prevention of some diseases such as familial hypercholesterolemia, its practical application remains on the horizon. Nevertheless, there is much we can do now to prevent early deaths in genetically high risk patients. Here we consider epidemiology as the parent discipline for applied genetics and as integral to primordial prevention. With new knowledge of special susceptibility and new understanding of the interaction of genetics and exposures, prevention of individual high-risk in the first place is realizable.We summarize here the known and candidate genes influencing atherosclerosis, hypertension, and thrombosis; their diagnosis; and some useful preventive approaches. MEDPED, an international scheme for detection of risk in medical pedigrees, is described, along with the cost and social implications of its application as a preventive strategy.     

Long-term consumption of a carbohydrate-restricted diet does not induce deleterious metabolic effects

Carbohydrate (CHO)-restricted diets have been recommended for weight loss and to prevent obesity, but their long-term effects have not been fully elucidated. This study was designed to evaluate the effect of long-term (>1 year) consumption of a low-CHO high-fat diet (“The optimal diet,” developed by Dr Kwaśniewski referenced herein) on lipid profile, glycemic control, and cardiovascular disease risk factors in healthy subjects. Of 31 “optimal” dieters enrolled in the study (17 women and 14 men, aged 51.7 ± 16.6 years), 22 declared adherence to the diet for more than 3 years. Average energy intake and principal nutrients consumed were assessed from 6-day dietary records provided by the participants. In most dieters, concentrations of β-hydroxybutyrate, free fatty acids, total cholesterol, and low-density lipoprotein cholesterol exceeded the upper limits of the reference ranges for nonstarved subjects. The metabolic profiles of most subjects were positive for several indicators, including relatively low concentrations of triacylglycerols, high levels of high-density lipoprotein cholesterol (HDL-C), and normal ratios of low-density lipoprotein cholesterol/HDL-C and total cholesterol/HDL-C. In most subjects, plasma concentrations of glucose, insulin, glucagon, cortisol, homocysteine, glycerol, and C-reactive protein were within reference ranges. Notably, in all but one subject, the homeostasis model assessment index of insulin resistance remained below the threshold for diagnosis of insulin resistance. These results indicate that long-term (>1 year) compliance with a low-CHO high-fat “optimal diet” does not induce deleterious metabolic effects and does not increase the risk for cardiovascular disease, as evidenced by maintenance of adequate glycemic control and relatively low values for conventional cardiovascular risk factors.     

Infinitesimal risk as public health crisis: News media coverage of a doctor-patient HIV contact tracing investigation

Among the most prominent health or medical stories covered in 1994 by the Australian news media was that concerning an HIV positive hospital obstetrician and the attempt by the New South Wales Health Department to trace and test 149 women on whom he had operated. All press and television coverage of the issue was reviewed. The surface news narrative of the search for missing, “innocent” mothers potentially infected with a deadly and infectious illness is shown to serve as a “hard news” pretext enabling a wider major discourse to operate about a health system accused as being captive to gay and civil libertarian politics, allowing “guilty” doctors at high risk of HIV to endanger “innocent” patients. Expert consensus held that the women were at “infinitesimal risk” of acquiring HIV. However, media accounts of the investigation all but belied this, illustrating that the news media's framing of risk has more to do with its reproduction of moral outrage components than with “scientific” notions of calculable risk.     

Relative contributions of health behaviours versus social factors on perceived and objective weight status in Canadian adolescents

ObjectivesPublic health interventions for adolescent “obesity prevention” have focused predominantly on individualistic health behaviours (e.g., diet and physical activity) at the expense of recognizing body weight diversity and the array of social factors (e.g., stigma and discrimination of marginalized identities) that may be linked to weight status. Research is needed to examine the extent to which individualistic health behaviours versus social factors contribute to weight status in adolescents. As such, the aim of this study was to investigate the relative contribution of individualistic health behaviours versus social factors to objective and perceptual indices of weight status.MethodsCross-sectional survey data were collected as part of the Toronto Public Health Student Survey and comprised students 12 to 19 years of age (N = 5515). Measures included perceived and objective weight status, social and demographic factors (e.g., gender, sexual orientation, school connectedness), and health behaviours (e.g., physical activity, nutritious consumption).ResultsFindings from latent variable regression models partially supported hypotheses, whereby social factors (i.e., age, sex, socio-economic access, sexual minority status) contribute similar amounts of variance, or relatively more variance in weight indices, compared to health behaviours (e.g., physical activity, nutritious consumption).ConclusionContrary to traditional views of adolescent weight status, physical activity (i.e., school-based, individual, active transport) and nutritious consumption (i.e., fruits, vegetables, milk) were not associated with weight status, when considering social factors. These findings challenge the utility of public health approaches that target individualistic behaviours as critical risk factors in “obesity prevention” efforts in adolescence.     

Gene–Environment Interaction: Definitions and Study Design

Study of gene–environment interaction is important for improving accuracy and precision in the assessment of both genetic and environmental influences. This overview presents a simple definition of gene–environment interaction and suggests study designs for detecting it. Gene–environment interaction is defined as “a different effect of an environmental exposure on disease risk in persons with different genotypes,” or, alternatively, “a different effect of a genotype on disease risk in persons with different environmental exposures.” Under this strictly statistical definition, the presence or absence of interaction depends upon the scale of measurement (additive or multiplicative). The decision of which scale is appropriate will be governed by many factors, including the main objective of an investigation (discovery of etiology, public health prediction, etc.) and the hypothesized pathophysiologic model. Five biologically plausible models are described for the relations between genotypes and environmental exposures, in terms of their effects on disease risk. Each of these models leads to a different set of predictions about disease risk in individuals classified by presence or absence of a high-risk genotype and environmental exposure. Classification according to the exposure is relatively easy, using conventional epidemiologic methods. Classification according to the high-risk genotype is more difficult, but several alternative strategies are suggested.     

Primordial Prevention of Cardiovascular Disease among African-Americans: A Social Epidemiological Perspective

Background. The primordial prevention of cardiovascular disease (CVD) among African-Americans represents a formidable challenge for public health. This paper discusses the nature of this challenge, highlighting the role that economic and cultural factors play in shaping the distributions of major CVD risk factors among African-Americans. The paper concludes with specific suggestions for research.Methods. Data from recent national health surveys on black/white differences in major CVD risk factors like hypertension, obesity, cholesterol, cigarette smoking, and physical inactivity were reviewed for the purpose of identifying promising avenues for primordial prevention research among African-Americans.Results. Cigarette smoking has a delayed onset among African-Americans compared to whites. Black/white differences in “vigorous” leisure-time physical activity (e.g., social dancing and team sports) are not apparent until around age 40. These findings have relevance for primordial prevention work in black communities since they suggest the existence of broad-based, health-relevant cultural norms which could support primordial prevention programs, such as regular physical activity, across the life cycle.Conclusions. CVD primordial prevention programs among African-Americans must be grounded in an understanding of how cultural values as well as economic conditions shape CVD risk factor distributions in this population. Ultimate success will depend on the strength of the partnerships that public health researchers, primary care providers, and community residents are able to build.     

Clinical and Translational Science Awards and Community Engagement: Now Is the Time to Mainstream Prevention into the Nation's Health Research Agenda

Although much attention is devoted to the slow process of cutting-edge “bench science” finding its way to clinical translation, less attention is paid to the fact that basic prevention messages, tests, and interventions never find their way into communities. The NIH Clinical & Translational Science Awards program seeks to address a broad mission of improving health, including both speeding up the incorporation of basic science discoveries throughout the clinical research pipeline and incorporating concerns of communities and practices into research agendas. The preventive medicine community now has an important opportunity to marry their mission of promoting and expanding prevention in communities to the nation's medical research agenda. This article suggests opportunities for collaboration.     

Disordered Eating and Unhealthy Weight Reduction Practices among Adolescent Females

Background.Dissatisfaction with body weight and the use of unhealthy weight reduction practices have been reported among adolescent females. There is a need for methodologically rigorous studies using large representative samples of adolescent females to accurately assess the prevalence of these behaviors and attitudes.Methods.Eight hundred sixty-nine Australian school girls ages 14–16 years were administered a self-report questionnaire to determine the prevalence of disordered eating behaviors, unhealthy dieting practices, and distorted body image. Anthropometric (height and weight) data were collected on each of these adolescent females.Results.The prevalences of disordered eating, unhealthy dieting, and distorted body image were 33, 57, and 12%, respectively. Over one-third (36%) of the total sample had used at least one “extreme” dieting method in the past month, i.e., “crash” dieting, fasting, slimming tablets, diuretics, laxatives, and/or cigarettes to lose weight. Of the total sample, 77% wanted to lose weight and 51% had tried to lose weight in the past month. Motivating factors for disordered eating and unhealthy dieting behaviors were peer pressure, media pressure, and the perception that extreme dieting strategies were harmless.Conclusion.The prevalence of disordered eating and dieting behaviors among adolescent females shown by this study suggests the need for preventive programs encouraging appropriate eating and dieting behaviors.     

Sexual Risk Behavior of Men Who have Sex with Men: Comparison of Behavior at Home and at a Gay Resort

This study compared sexual behavior of gay and bisexual men (N = 551) while at their primary residence to their behavior while vacationing at a gay resort community. Participants reported behavior for the days they spent in the resort and for their last 60 days in their home residences. Overall, 11 times more non-main partners were reported for unprotected anal intercourse (UAI) per day while in the resort as for the “at home” period. Regression analysis identified negative attitudes toward condoms, less concern about AIDS, and daily number of non-main, male partners at home with whom UAI occurred as significant predictors of the daily number of non-main male partners with whom holidaymakers engaged in UAI while in the resort area. The results suggest that sexual risk taking by men who have sex with men (MSM) while on holiday may be elevated over that at home and that prevention efforts need to be promoted in gay resorts. Behavioral surveillance research would be helpful in better characterizing the current social contexts of sexual risk taking by MSM. Theory-based studies of the nature of risk-taking and sexual decision-making on “gay holiday” could inform the development of empirically proven and conceptually grounded interventions.     

Bridging the gap: Translating research into policy and practice

Effective physical activity interventions do not achieve their full potential if they are not applied beyond their original testing in research studies. Potentially effective interventions can be adopted in community settings through the efforts of numerous agencies, organizations, and individuals. This paper highlights the important roles of public health practitioners and policy makers, who differ in their decision-making processes. To enhance the uptake of evidence-based interventions, several steps are needed to: build the science by moving upstream, increase the understanding of practice-based evidence, move beyond the “what” to the “how,” re-frame the dissemination challenges, place greater emphasis on workforce development, and make research more accessible for policy audiences. The most effective strategies to bridge the gap between research and practice, will have at their heart, effective academic-practice-policy maker partnerships.     

Comparison of patterns of smoking behavior change among smokers in the Multiple Risk Factor Intervention Trial (MRFIT)

The Multiple Risk Factor Intervention Trial (MRFIT) is a 6-year clinical trial for the study of the prevention of heart disease. Twelve thousand eight hundred and sixty-six men in the upper 10–15% of heart attack risk were randomly assigned to Special Intervention (SI) or Usual Care (UC). The SI participants received “risk factor” (hypertension, hypercholesterolemia, and cigarette smoking) intervention at the clinical centers; the UC participants were referred to their usual source of medical care for treatment. Forty percent of SI and 21% of UC smokers at entry reported not smoking at year 4, with lighter smokers in both treatment groups reporting significantly more cessation than heavier smokers. The greatest SI-UC difference in cessation rate was achieved during the first year of the program. The use of serum thiocyanate, an objective indicator of cigarette smoking, avoided problems inherent in self-reported data. Misreporting of smoking status was found in both groups with more occurring among the SI smokers. Cohort analysis revealed that of the smokers who stopped during the first year of the trial, 68% of SI and 57% of UC remained abstinent through the 4-year follow-up. Of the smokers who stopped later in the program the UC had better maintenance rates than the SI.     

Regional risk factors for health inequalities in Scotland and England and the “Scottish effect”

This paper uses data from the Scottish Health Survey 2003 and the comparable Health Survey for England 2003 to look at whether Scotland's poor health image and mortality profile is reflected in regional inequalities in prevalence of four risk factors for cardiovascular disease: fruit and vegetable consumption, smoking, obesity and diabetes. It also looks at the “Scottish effect” – how much of any difference between and within Scotland and England remains once socio-demographic factors have been taken in to account. The paper then uses regional analyses to determine the extent to which areas within England and Scotland contribute to their national health advantage and disadvantage. All 2003 strategic health authorities in England and Scottish health boards were compared with Greater Glasgow health board as the reference category.The results showed that significant geographic variation in the risk factors remained once individual economic status was taken into account, but the relationship was complex and varied in strength and direction depending upon risk factor involved and gender of respondent. A small number of areas had significantly lower odds of fruit and vegetable consumption of five portions or more a day in men, compared with Greater Glasgow. In contrast some areas had significantly higher odds of fruit and vegetable consumption for women compared with Greater Glasgow.There was greater geographic variation in the odds of smoking in women than in men. Respondents in the south west and southeast of England (areas which usually show health advantage) did not show significantly lower odds of smoking compared with Greater Glasgow once socio-economic variation, age and urban residence was taken into account. It was respondents from central England that had lower odds of smoking than might be expected. Obesity stood out as the single risk factor that had demonstrated a “Scottish effect” in women only.     

Achieving Population Health in Accountable Care Organizations

Although “population health” is one of the Institute for Healthcare Improvement’s Triple Aim goals, its relationship to accountable care organizations (ACOs) remains ill-defined and lacks clarity as to how the clinical delivery system intersects with the public health system.Although defining population health as “panel” management seems to be the default definition, we called for a broader “community health” definition that could improve relationships between clinical delivery and public health systems and health outcomes for communities.We discussed this broader definition and offered recommendations for linking ACOs with the public health system toward improving health for patients and their communities.WITH THE PASSAGE OF THE Affordable Care Act (ACA),1 the United States has turned its attention to improving the quality of health care while simultaneously decreasing cost. As we move toward alternative and global payment arrangements, the need to understand the epidemiology of the patient population will become imperative. Keeping this population healthy will require enhancing our capacity to assess, monitor, and prioritize lifestyle risk factors that unduly impact individual patient health outcomes. This is especially true, given that only 10% of health outcomes are a result of the medical care system, whereas from 50% to 60% are because of health behaviors.2,3 To change health behaviors, it will be necessary to engage in activities that reach beyond the clinical setting and incorporate community and public health systems.4The Institute for Healthcare Improvement (IHI), a leading not-for-profit organization dedicated to using quality improvement strategies to achieve safe and effective health care, has developed the Triple Aim initiative5 as a rubric for health care transformation. The three linked goals of the Triple Aim include improving the experience of care, improving the health of populations, and reducing per capita costs of health care.6 However, although two of the three aims–experience of care and cost reduction–are self-explanatory, there is little consensus about how to define population health. Words like “panel management,” “population medicine,” and “population health” are being used interchangeably. Berwick et al.6 describe the care of a population of patients as the responsibility of the health care system and use broad-based community health indicators as evidence of improvement. Other recent publications have attempted to describe population health from the hospital,7–10 primary care,11 and community health center perspectives.12 The “clinical view” identifies the population as those “enrolled” in the care of a specific provider, provider or hospital system, insurer, or health care delivery network (i.e., panel population).7 Alternatively, from the public health perspective,8 population is defined by the geography of a community (i.e., community population) or the membership in a category of persons that share specific attributes (e.g., populations of elderly, minority population). In either case, the context of a community and the existing social determinants of health, ranging from poverty to housing, are known to have substantial impact on individual health outcomes. Thus, ensuring the health of a population is highly dependent on addressing these social determinants and requires collaborative relationships with community institutions outside the health care setting.13,14Two key concepts that will greatly influence the definition and actualization of population health in the post-ACA era include the accountable care organization (ACO)15 and the patient-centered medical home (PCMH).16 The ACO represents an integrated strategy at the delivery system level to respond to payment reform.15 These integrated systems of care are poised to manage a population of patients under a global payment model. The PCMH is focused on transforming primary care to better deliver “patient-centered” care and to address the whole patient, including their health and social needs.17,18 Both models will need to identify, monitor, and manage their “population” of patients. However, their ability to extend their definition of population health to encompass the entire community will depend on resources, market share, and the strength and capacity of collaborating community and public health organizations. As integrated delivery systems are asked to do more than focus on their own patients, they will require additional resources. These may come from a realignment of existing programs (community benefits), a return on investment from effective preventive care, or collaborative relationships with existing community and public health organizations.In this article, we discuss two major points regarding ACOs and their approach to population health. First, ACOs should be committed to serving the health of the people in the communities from which their population is drawn, and not just the population of patients enrolled in their care to achieve the population health goal. Second, to achieve this expanded definition of population health, ACOs will need to engage in collaborative efforts with community agencies and the public health system. We describe a “community” definition of population health to be used in lieu of the “panel” definition and then outline the resources needed and strategies for collaboration. Finally, we offer recommendations to assist ACOs in realizing their population health goal.     

Traditional medicine and lead-containing preparations in Nigeria

Traditional medicine, its preparations and practices, plays a major role in the health care of the community of Nigeria. In many cases the native doctor (“Babalawo”) and the local herbalist (“Eleweomo”) are the only practitioners available for the treatment of illness. Even in the towns where allopathic medicine is available the limited facilities it offers make many patients rely on traditional methods. Little is known of the pharmacological action of these traditional remedies which the native doctor prescribes. Our own studies have concentrated on the metal content of such materials. Here we report on the material known as “tiro” which is used for the treatment of eye infections and disease as well as an “eye cleaner” and cosmetic. On analysis we found that all samples of tiro measured contained lead ranging from 12·8 to 81·1% (w/w), with a mean concentration over all samples determined of 50·1% (w/w). In addition, it was also found that tiro is used by some members of the Nigerian community in Britain and is brought in in decorative containers as a gift. The extent of use in this country still remains to be determined, however. The use of lead-containing preparations^* in traditional practices presents a significant health hazard to a substantial section of the world's population. We suggest urgent steps are required to encourage governments to establish education programmes to eliminate this avoidable source of morbidity among their populations.     

“Omics” research,monetization of intellectual property and fragmentation of knowledge: can clinical epidemiology strengthen integrative research?

An analysis of the contributions of “omics technologies” to human health and clinical care needs to address the relationships between internal issues (e.g., methodological shortcomings in “omics” research and clinical biology) and external influences. Among the latter, monetization of intellectual property (IP) appears to be a powerful force favoring methodological limitations and an excessive reductionism and fragmentation of biological knowledge. Following economic successes in other industries (semiconductors, software, and “dot-coms”), monetization of IP tries to market small fragments of big research “puzzles”; the strategy seems partly responsible for the biotech industry having underperformed methodological, clinical, and economic expectations. Hence, internal, purely scientific reasons can hardly explain failures in the application of long-proven principles of clinical epidemiology to the discovery and validation of diagnostic and prognostic tests. Nevertheless, this paper also sketches methodological proposals that may help integrate microbiological, clinical, and environmental evidence. Clinical and epidemiological reasoning, knowledge, and methods need to be applied on a much wider scale than until now by “omics” studies that aim at making inferences relevant for human beings. Rather than adopting the values and norms of “science business,” “omics research” could apply a diversity of clinicoepidemiological models favoring integrative research.     

Community-level HIV intervention in 5 cities: final outcome data from the CDC AIDS Community Demonstration Projects

OBJECTIVES: This study evaluated a theory-based community-level intervention to promote progress toward consistent condom and bleach use among selected populations at increased risk for HIV infection in 5 US cities. METHODS: Role-model stories were distributed, along with condoms and bleach, by community members who encouraged behavior change among injection drug users, their female sex partners, sex workers, non-gay-identified men who have sex with men, high-risk youth, and residents in areas with high sexually transmitted disease rates. Over a 3-year period, cross-sectional interviews (n = 15,205) were conducted in 10 intervention and comparison community pairs. Outcomes were measured on a stage-of-change scale. Observed condom carrying and intervention exposure were also measured. RESULTS: At the community level, movement toward consistent condom use with main (P < .05) and nonmain (P < .05) partners, as well as increased condom carrying (P < .0001), was greater in intervention than in comparison communities. At the individual level, respondents recently exposed to the intervention were more likely to carry condoms and to have higher stage-of-change scores for condom and bleach use. CONCLUSIONS: The intervention led to significant communitywide progress toward consistent HIV risk reduction.     

Effects of Health Information in Youth and Young Adulthood on Risk Factors for Chronic Diseases—20-Year Study Results from the Amsterdam Growth and Health Longitudinal Study

In the Amsterdam Growth and Health Longitudinal Study (AGAHLS) biological risk factors for chronic diseases were measured on eight separate occasions over a period of 20 years in a group of apparently healthy males and females (n = 164). Data were first collected from participants at 13 years of age. At each of the eight measurements, a medical checkup was performed and participants were given information about their current health status based on their personal biological risk factor profile (cholesterol, blood pressure, body composition, and physical fitness). A comparable group (n = 113) was measured on two occasions only: at age 13 and again at age 33. It was hypothesized that the group with eight measurements would present a more favorable 20-year development of the risk factors than the group with only two measurements. In the present article the six additional measurements with personal feedback of one's health status were perceived as an “intervention,” even though the AGAHLS never intended to improve the lifestyle or health of its subjects. The intervention appeared to have had a positive effect on body fat distribution and, in men, on systolic blood pressure. However, it was expected that these significant results were not true effects of the intervention, but that they were type-I errors. For the other variables, total cholesterol, high-density lipoprotein cholesterol, and the ratio between these two, for the sum of four skinfolds, diastolic blood pressure, neuromotor fitness, and for maximal oxygen uptake, the 20-year development did not differ between the two groups. Thus, the effects of a 20-year health measurement and information intervention begun in youth on biologic risk factors for chronic diseases were limited. The absence of clear significant findings may be due to the low contrast between the two groups, as only six intervention measurements were conducted over a period of 20 years. Another reason may be that the young and relatively healthy population under study here was not amenable to changing their fitness and health.