Annual Review of Public Health - Volume 32, 2011

Cardiovascular disease (CVD) became the leading cause of chronic disease morbidity and mortality in industrialized countries in the twentieth century. In many nations, it peaked and began to decline, while in developing countries it is rising. The contributions of risk factors, sociocultural changes, and medical care are debated, but all play a role in understanding these disease patterns. Public health approaches such as dietary change along with widespread use of medications such as aspirin, statins, diuretics, and beta-blockers may impact future trends in this chronic disease epidemic.

Mortality rates from coronary heart disease (CHD), which had risen during the twentieth century in many countries, started declining in some countries during the 1960s. Once initial skepticism about the validity of the observed trends dissipated, researchers attempted to generate explanations about the events that had transpired using a variety of techniques, including ecological examinations of the trends in risk factors for CHD and changes in management of CHD, multivariate risk equations, and increasingly sophisticated modeling techniques. Improvements in risk factors as well as changes in cardiac treatments have both contributed to the reductions in CHD mortality, although estimates of their contributions have varied among countries. Models suggest that additional large reductions in CHD mortality are feasible by either improving the distribution of risk factors in the population or raising the percentage of patients receiving evidence-based treatments.

Cardiovascular diseases (CVD) account for one-third of annual global mortality. The aggregated benefits of concurrently controlling common CVD risk factors, such as dyslipidemia and hypertension, in people at overall risk for CVD is postulated to be more efficient than treating each individual risk factor to target. Administration of a polypill consisting of cholesterol-lowering (statins), antihypertensive, and antiplatelet agents together would simultaneously lower multiple risk factors, and applying such a population risk-reduction strategy would drastically reduce CVD incidence. This idea has generated much controversy and debate over the past decade. A few studies have emerged providing early evidence about the safety and efficacy of such a pill, and the results of ongoing and planned studies of outcome are eagerly anticipated. In this article, we review and interpret the existing evidence as well as explore the potential of a polypill for primary and secondary prevention of CVD.

This article reviews the historical declines in cardiovascular mortality and provides an overview of the contribution of social and economic factors to disease change. We document the magnitude of declines in cardiovascular diseases and the major role of changes in conventional risk factors, and we review the contributions of social determinants to changes in disease rates. We conclude by arguing that understanding patterns and trends of social inequalities in cardiovascular disease and its risk factors requires consideration of the specific intersections of health and social exposures acting across the life course in different settings, in both time and place.

Sodium consumption is a target for prevention of cardiovascular disease (CVD). The relationship between sodium intake and blood pressure (BP) is well-established, but the relationship with CVD is less clear. This review focuses on studies investigating the association between sodium intake and CVD within five principal subgroups: age, underlying BP, gender, body size, and ethnicity. We conclude that sodium reduction results in decreased CVD risk in the general population, and some susceptible subgroups may especially benefit from preventive efforts. Older individuals, those with underlying elevated BP, and those with increased body size may benefit most, but men and women of all ages, ethnicities, and normotensives also experience reduced CVD risk in relation to lowered sodium intake. Public health policy to reduce sodium intake in the United States would have significant cost-savings, far greater than the cost of intervention, and would also result in a significant gain in quality-adjusted life years.

Linked administrative databases offer a powerful resource for studying important public health issues. Methods developed and implemented in several jurisdictions across the globe have achieved high-quality linkages for conducting health and social research without compromising confidentiality. Key data available for linkage include health services utilization, population registries, place of residence, family ties, educational outcomes, and use of social services. Linking events for large populations of individuals across disparate sources and over time permits a range of research possibilities, including the capacity to study low-prevalence exposure-disease associations, multiple outcome domains within the same cohort of individuals, service utilization and chronic disease patterns, and life course and transgenerational transmission of health. Limited information on variables such as individual-level socioeconomic status (SES) and social supports is outweighed by strengths that include comprehensive follow-up, continuous data collection, objective measures, and relatively low expense. Ever advancing methodologies and data holdings guarantee that research using linked administrative databases will make increasingly important contributions to public health research.

The essential purpose of public health surveillance is to monitor important health outcomes and risk factors and provide actionable information to practitioners, policy makers, researchers, and the public to prevent or ameliorate exposure, disease, and death. Although separate 1970s-era acts of Congress made possible the creation of modern occupational health and environmental public health surveillance, these acts also led to fragmented responsibilities and unconnected data across federal agencies. Having a well-defined purpose for systematically collecting relevant data is key, and state and local programs play a crucial role in conducting meaningful surveillance and connecting it with evidence-based outreach and interventions. Congress has directed monies to environmental public health surveillance and capacity has improved, yet no analagous funding has occurred to address the fragmentation found within occupational health surveillance. This article provides a review of the advances and important themes within occupational health and environmental public health surveillance over the past decade.

The rapid growth in noncommunicable diseases (NCDs), including injury and poor mental health, in low- and middle-income countries and the widening social gradients in NCDs within most countries worldwide pose major challenges to health and social systems and to development more generally. As Earth's surface temperature rises, a consequence of human-induced climate change, incidences of severe heat waves, droughts, storms, and floods will increase and become more severe. These changes will bring heightened risks to human survival and will likely exacerbate the incidence of some NCDs, including cardiovascular disease, some cancers, respiratory health, mental disorders, injuries, and malnutrition. These two great and urgent contemporary human challenges—to improve global health, especially the control of NCDs, and to protect people from the effects of climate change—would benefit from alignment of their policy agendas, offering synergistic opportunities to improve population and planetary health. Well-designed climate change policy can reduce the incidence of major NCDs in local populations.

As more is learned about genetic susceptibility to occupational and environmental hazards, there will be increasing pressure to use genetic susceptibility information in setting occupational health standards. Historically, this has not been done, but a growing body of research assesses inherited genetic factors as modifiers of the effects of hazardous exposures. Additionally, acquired genetic and epigenetic characteristics could also be used in standard setting. However, for both inherited and acquired genetic characteristics, many scientific, ethical, legal, and social issues could arise. Investigators need to examine the potential role and implications of using genetic information in standard setting. In this review, we focus primarily on inherited genetic factors and their role in occupational health standard setting.

In 2007, the U.S. National Research Council (NRC) published a groundbreaking report entitled Toxicity Testing in the 21st Century: A Vision and a Strategy. The purpose of this report was to develop a long-range strategic plan to update and advance the way environmental agents are tested for toxicity. The vision focused on the identification of critical perturbations of toxicity pathways that lead to adverse human health outcomes using modern scientific tools and technologies. This review describes how emerging scientific methods will move the NRC vision forward and improve the manner in which the potential health risks associated with exposure to environmental agents are assessed. The new paradigm for toxicity testing is compatible with the widely used four-stage risk assessment framework originally proposed by the NRC in 1983 in the so-called Red Book. The Nrf2 antioxidant pathway provides a detailed example of how relevant pathway perturbations will be identified within the context of the new NRC vision for the future of toxicity testing. The implications of the NRC vision for toxicity testing for regulatory risk assessment are also discussed.

Populations today face increasing health risks from human-induced regional and global environmental changes and resultant ecological nonsustainability. Localized environmental degradation that has long accompanied population growth, industrialization, and rising consumerism has now acquired a global and often systemic dimension (e.g., climate change, disrupted nitrogen cycling, biodiversity loss). Thus, the economic intensification and technological advances that previously contributed to health gains have now expanded such that humanity's environmental (and ecological) footprint jeopardizes global population health. International data show, in general, a positive correlation of a population's health with level of affluence and size of per-person footprint. Yet, beyond a modest threshold, larger footprints afford negligible health gain and may impair health (e.g., via the rise of obesity). Furthermore, some lower-income countries have attained high levels of health. Many changes now needed to promote ecological (and social) sustainability will benefit local health. Continued improvement of global health could thus coexist with an equitably shared global environmental footprint.

The childhood obesity epidemic has stimulated the emergence of many policy and environmental strategies to increase healthy eating and active living, with relatively few research recommendations identifying the most effective and generalizable strategies. Yet, local, state, and national decision makers have an urgent need to take action, particularly with respect to lower-income and racial and ethnic populations at greatest risk. With the surge of promising and emerging policy and environmental strategies, this review provides a framework, criteria, and process modeled from existing expert classification systems to assess the strength of evidence for these strategies. Likewise, this review highlights evidence gaps and ways to increase the types and amount of evidence available to inform policy and environmental strategies. These priorities include documenting independent and interdependent effects, determining applicability to different populations and settings, assessing implementation fidelity and feasibility, identifying cumulative benefits and costs, ascertaining impacts on health equity, and tracking sustainability.

Marked health inequities exist between regions, between countries, and within countries. Reducing these inequities in health requires attention to the unfair distribution of power, money, and resources and the conditions of everyday life. These are the social determinants of health. The World Health Organization (WHO) Commission on Social Determinants of Health (CSDH) brought together a global evidence base of what could be done to reduce these health inequities, demonstrating that economic and social policy, if done well, can improve health and health equity. A global movement for health equity was reignited by the WHO Commission on Social Determinants of Health when it made a call to action upon delivering its final report.

We review human studies on the relation between acute exposures to prenatal famine and adult physical and mental health. These studies are observational and include exposures to a famine environment by natural or man-made causes or, more commonly, from the interplay between natural and human factors. These natural experiments provide an opportunity to examine long-term outcomes after famine exposures by comparing exposed and nonexposed individuals.

The studies show consistent associations between prenatal famine and adult body size, diabetes, and schizophrenia. For other measures of adult health, findings are less robust. A relation between prenatal famine and some reported epigenetic changes may provide a potential mechanism to explain specific associations. Much progress can be made if current separate studies are further analyzed with comparable definitions of exposures and outcomes and using common analytic strategies.

In recent decades, public health policy and practice have been increasingly challenged by globalization, even as global financing for health has increased dramatically. This article discusses globalization and its health challenges from a vantage of political science, emphasizing increased global flows (of pathogens, information, trade, finance, and people) as driving, and driven by, global market integration. This integration requires a shift in public health thinking from a singular focus on international health (the higher disease burden in poor countries) to a more nuanced analysis of global health (in which health risks in both poor and rich countries are seen as having inherently global causes and consequences). Several globalization-related pathways to health exist, two key ones of which are described: globalized diseases and economic vulnerabilities. The article concludes with a call for national governments, especially those of wealthier nations, to take greater account of global health and its social determinants in all their foreign policies.

The large increase in obesity in the past 30 years has often been explained in rational choice terms; for example, a decline in food prices has engendered greater food consumption. On closer examination, this kind of explanation does not fit the facts of the current obesity epidemic. Instead, an unprecedented expansion in the scope, power, and ubiquity of food marketing has coincided with an unprecedented expansion in food consumption in predictable ways.

Ongoing protestations that the causes of the recent increase in obesity are unknown may overstate the case. Ample evidence indicates that the obesity epidemic is, at least to a large degree, the result of increased marketing power over the American diet. Only by reigning in or countering marketing power can rationality be restored to the dietary choices of Americans.

Since the 1980s, ecological models of health promotion have generated a great deal of enthusiasm among researchers and interventionists. These models emerged from conceptual developments in other fields, and only selected elements of the ecological approach have been integrated into them. In this article, we describe the tenets of the ecological approach and highlight those aspects that have been integrated into ecological models used in health promotion. We also analyze how ecological models have been applied to the study of two important public health issues, namely physical activity promotion and the increased consumption of fruits and vegetables, by conducting an archival study of published research. Finally, we make a statement regarding the usefulness of ecological models for research and practice and propose recommendations for future research, program planning, and evaluation.

This review examines environments in relation to cardiometabolic diseases in Indigenous populations in developed countries. Environmental factors are framed in terms of context (features of places) and composition (features of populations). Indigenous peoples are seen to have endured sociopolitical marginalization and material disadvantage spanning generations. Past adverse collective experiences, modified by culture, are reflected by current heterogeneity in environmental context and composition. As risk conditions, unfavorable contextual and compositional exposures influence the expression of cardiometabolic risk for individuals. Minimal research has evaluated heterogeneity in risk conditions against heterogeneity in cardiometabolic diseases between or within Indigenous populations. Thus far, the features of populations, not of places themselves, have been implicated in relation to cardiometabolic diseases. Behavioral, psychosocial, and stress-axis pathways may explain the relationships between risk conditions and cardiometabolic diseases. Implications of environmental factors and their pathways as well as important research needs are discussed in relation to ecological prevention to reduce cardiometabolic diseases.

Physical activity improves health. Different types of activity promote different types of physiologic changes and different health outcomes. A curvilinear reduction in risk occurs for a variety of diseases and conditions across volume of activity, with the steepest gradient at the lowest end of the activity scale. Some activity is better than none, and more is better than some. Even light-intensity activity appears to provide benefit and is preferable to sitting still. When increasing physical activity toward a desired level, small and well-spaced increments will reduce the incidence of adverse events and improve adherence.

Prior research on the relationship between activity and health has focused on the value of moderate to vigorous activity on top of an indefinite and shifting baseline. Given emerging evidence that light activities have health benefits and with advances in tools for measuring activities of all intensities, it may be time to shift to zero activity as the conceptual starting point for study.