ing world's leading cause of death. Even in 1990, CVDs were the leading cause of death for all major geographic regions of the developing world except India and Sub-Saharan Africa.
Although CVD mortality is well known to be high for men and for older age groups, it is also the major cause of mortality in the economically productive age group of 30-69 years and in women (Table 1-3). Not surprisingly, in 1990 CVD caused three times as many deaths in 30-to 69-year-old men and women as did infectious and parasitic diseases worldwide. This is true for all regions of the world, except Sub-Saharan Africa, where the number of deaths from CVD and infectious or parasitic diseases was about equal. Recent data suggest that mortality from stroke in Sub-Saharan Africa is higher than previously reported and confirm the relatively young age of the victims (United Republic of Tanzania, 1997).
BOX 1-3 Hypertension: A Global Disease
Elevated blood pressure or hypertension emerges as a major cause of hemorrhagic strroke, hypertensive heart disease, and hypertensive kidney failure even before : coronary heart disease and atherothrombotic stroke become major causes of mortality (Whelton et al., 1995). Using a conservative definition for hypertension as blood pressure above 160 mm Hg systolic or above 95 mm Hg diastolic, the prevalence of hypertension, even in Sub-Saharan Africa, ranges from 10 to 33 percent in 30- to 49 year-old men and women (Nissinen et al., 1988). The INTERSALT study carried out in 32 countries, many of them developing, used carefully standardized measurements of blood pressure to confirm substantial prevalence of blood pressures above 140/90 mm Hg in most countries, both developed and developing (INTERSALT cooperative Research Group, 1988). In addition, the level of awareness worldwide is low, as are treatment and control of elevated blood pressure (Marques-Vidal and Tuomilehto, 1997).
A practical approach to CVD control is primordial prevention (i.e., prevention of the risk factors themselves) Hypertension may be considered either a risk factor for CVD or disease in itself. This raises the issue of whether hypertension is preventable. Some of its risk factors such as age, male sex, and family history are nonmodifiable. The modifiable risk factors include obesity, sedentary life-style, high-sodium diet, alcohol consumption, and possibly other dietary factors. Clinical trials to prevent the development of hypertension suggest that weight control, increased physical activity, and lower dietary intakes of sodium and alcohol show good potential for primordial prevention (Cutler 1993). Despite their low cost relative to treatment, these strategies have not yet been investigated in developing countries. Without successful primordial or primary prevention, significant disability and mortality are likely to be caused by hypertension.