Relationships among Major Risk Factors and the Burden of Cardiovascular Diseases, Diabetes, and Chronic Lung Disease

Excerpt

Cardiovascular, respiratory, and related disorders (CVRDs) are a subset of noncommunicable diseases (NCDs) that are an important and increasing cause of morbidity and mortality in low- and middle-income countries (LMICs). CVRDs share common risk factors such as smoking, poor diet, and physical inactivity. They also share common interventions at the clinical, public health, and policy levels. Public health professionals and decision makers share a widespread notion that CVRDs are diseases of the affluent (WHO 2010b). Yet recent cross-national studies have demonstrated that the burden of CVRDs falls disproportionately on lower-income countries and disadvantaged groups within countries. Prevention and control of CVRDs, then, have important equity implications. Addressing CVRDs also fits in with the Sustainable Development Goals that focus on reducing poverty and improving health, particularly through mechanisms (such as universal health coverage) that can address the rise in CVRD risk factors and the potential impoverishing effects of chronic illness.

The concept that current or past exposure to specific factors increases the risk of future ischemic heart disease (IHD) was first established in the Framingham Heart study in the United States (Kannel and others 1961), but it has been validated extensively in LMICs (O’Donnell and others 2010; Yusuf and others 2004). These risk factors are now well established globally, not only for IHD (Pearson and others 2003; Perk and others 2013; Yusuf and others 2001; Yusuf and others 2004), but also for stroke (Colditz and others 1988; Markus 2011; O’Donnell and others 2010), other cardiovascular diseases (CVDs) (Greenland and others 2010; Khatibzadeh and others 2013; Mosca and others 2004; Smith and others 2011), diabetes (Caballero 2003; Singh and others 2010; Weber and others 2012; Zimmet and others 1999), chronic lung disease (Madison, Zelman, and Mittman 1980; Palta and others 1991; Salvi and Barnes 2009; Strope and Stempel 1984), and other chronic NCDs (Allender and others 2011; Ezzati and Riboli 2013; Hallal and others 2012). Exposure to these risk factors may occur early in life, including in utero, and continue throughout life or may be limited to only certain phases of the life span. These risk factors may be strongly influenced by socioeconomic and environmental determinants, policy and legislative interventions, lifestyle and behavioral choices, and familial and genetic predisposition. Among modifiable risk factors, reducing the level of individual or population risk or discontinuing the exposure leads to corresponding reductions in the magnitude of disease burden and preventable deaths. In-depth knowledge of these relationships as well as the distribution of risk factors in the population provides a sound basis for developing prevention strategies at the individual and population levels.

This chapter describes recent trends in mortality and morbidity from CVRDs in LMICs and the specific conditions (including IHD, structural heart disease, heart failure, stroke, peripheral arterial disease, diabetes, kidney disease, and chronic lung disease) and risk factors covered in this volume. It then reviews the evidence regarding the complex interrelationships between specific risk factors, their early- and late-life determinants, and their corresponding influence on CVRD risk later in life. Finally, it presents steps for addressing CVRD risk factors and for reducing preventable deaths within a socioecological framework.