**2. Overview of cardiovascular diseases and risk factors in Sub-Saharan Africa**

#### **2.1 Overview**

CVDs are a group of disorders of the heart and blood vessels; they include mainly [3]:


*Lifestyle and Cardiovascular Risk Factors: Urban Population versus Rural Population… DOI: http://dx.doi.org/10.5772/intechopen.96881*


CVDs are promoted by a number of factors called "risk factors" (RFs).The main CVRFs are: poor diet, lack of physical activity, smoking, and harmful use of alcohol. These RFs, related to lifestyle, are called behavioral RFs. They can be the cause of physiological disturbances such as high blood pressure, hyperglycemia, hyperlipidemia and obesity; they are called intermediate risk factors.

CVRFs are also classified into non-modifiable factors and modifiable factors. The unchangeable risk factors are age, sex, race, and inheritance. Modifiable factors correspond to behavioral and biological factors. The **Figure 1** shows the link between CVRFs and CVDs.

STEPS studies carried out on a continental African scale in the 1980s indicated high prevalence of CVRFs and especially hypertension.

The summary of the results of these studies is presented in **Table 1**.

Cardiovascular diseases are become a major public health problem throughout the African Region. The main CVDs are: high blood pressure, stroke,

#### **Figure 1.**

In 2012, an estimated 17.5 million people died from these diseases, representing 30% of all deaths worldwide. An estimated 7.5 million of these deaths are due to coronary heart disease and 6.7 million to stroke. Low- and middle-income countries are disproportionately affected, accounting for over 80% of CVD deaths. By 2030, nearly 23.6 million people will die from cardiovascular diseases, primarily heart disease and stroke. According to projections, these conditions will remain the lead-

*Lifestyle and Epidemiology - The Double Burden of Poverty and Cardiovascular Diseases…*

During the 3rd high-level meeting on NCDs, it was reported that seven in 10 people (71%) worldwide die from these diseases, which mainly consist of cardiovascular disease, cancer, diabetes and lung chronic diseases, an average of 41 million people each year. These include 15 million people dying from NCDs between the ages of 30 and 69; over 85% of these "premature" deaths occur in low- and

CVDs, as other NCDs, are favored by factors that are related to genetics, physiology and sociological environment, and are called risk factors (RFs) or specifically

The main RF of CVDs or NCDs, are related to the sociological environment, particularly with our lifestyle or our everyday behavior and are thus called behavioral RFs; they are thus deeply influenced by the culture and customs of the environment. It is this link between the sociological environment and the RFs of CVDs or NCDs, which could determine the African disparities between the rural environ-

In this chapter, we want to present an overview on CVDs and their RFs in rural and urban areas in Sub-Saharan Africa (SSA), to indicate some characteristic features of lifestyle in these two environments and to draw conclusions from them in terms of prospects for combating this new epidemic in this part of the world.

We conducted a literature review related to the topic of the chapter, based on the available documentation as well as on the international scientific literature accessible through the PUBMED search engine where, after entering the keywords, the most relevant publications were selected. The use of this documentation was carried out taking into account the general situation in the world, the specific situation of the ASS with comparative observation between rural and urban areas.

**2. Overview of cardiovascular diseases and risk factors in Sub-Saharan**

CVDs are a group of disorders of the heart and blood vessels; they include

• coronary heart disease – disease of the blood vessels supplying the heart

• cerebrovascular disease – disease of the blood vessels supplying the brain;

ment, guardian of traditional culture and the urban environment, strongly

ing cause of death in the world [1].

middle-income countries [2].

cardiovascular risk factors (CVRFs).

influenced by Western culture.

**1.2 Methodology**

**Africa**

**2.1 Overview**

mainly [3]:

**164**

muscle;

**1.1 Objective of the presentation**

*Relationship between CVRFs and CVDs. Source: Wong ND., Black et Grdin JM., Preventive cardiology: a practical approach, Chicago, Mc Graw Hill, 2005.*


**Country**

**167**

 **Year1**

**%Who**

**% Who Ate**

**% Not Engaged**

**%**

**% With**

**% With**

**% With**

**% With**

**% With > 3 of**

**% With > 3 of**

**% With > 3 of** **the CRFs, Ages**

**24–64 Years**

**Old**

**the CRFs, Ages** **45–64 Years Old**

**Who**

**Raised**

**Raised**

**Raised Total**

**None of**

**the CRFs, Ages**

**in Vigorous**

**Physical**

**Are**

**Blood**

**Blood**

**Blood**

**the**

**25–44 Years Old**

**Cholesterol6**

**CRFs7**

**Obese3**

**Pressure4**

**Glucose5**

**Activity**

**Currently**

**< 5 Servings**

**Smoke**

**of F&V Per**

**Tobacco**

Mozambique

Niger

Sao Tome

2008

 5.5

83.3

51.6

 35.0

 38.6

 6.5

7.5

 6.4

15.6

36.1

22.1

*DOI: http://dx.doi.org/10.5772/intechopen.96881*

and Principe

Seychelles

Sierra Leone 2009

Swaziland

Tanzania

Togo

Zambia

Zanzibar

*Source of Data: The World Health* 

*1Year of most recent STEPS survey.* *2Percentage who ate less than 5 combined servings of fruit and/or vegetables on average pet day*

*3Percentage who are obese (BMI at least 30 kg/m2).* *4Percentage with raised BP (SBP at least 140 and/or DBP at least 90 mm Hg or currently on medication for raised BP).*

*5Percentage with raised blood glucose as defined below or currently on medication for raised blood glucose:*

*• plasma venous value \_7.0 mmol/L or \_126 mg/dl;* *•capillary whole blood value \_6.1 mmol/L or \_110 mg/dl.*

*6Percentage with raised total blood cholesterol.*

*7CRFs are the combined risk factors including (a) current daily smokers; (b) consumption*

*overweight (BMI at least 25 kg/m2); (e) raised BP (SBP at least 140 and/or DBP at least 90 mm Hg or currently on medication for raised BP).*

*This table (Table 1) shows across the continent a very high rate of insufficient physical activity, a high rate of arterial hypertension*

*compared to the rates observed in Western countries and a higher rate of a combination*

**Table 1.** *Prevalence*

 *of behavioral*

 *RFs and classical biological CVRFs according to STEPS studies [4].*

 *of less than 5 servings of fruits and/or vegetables on average per day; (c) low level of activity (<600* 

 *of RFs from 45 years.*

 *with nevertheless disparities between the countries, a relatively low rate of obesity*

*MET-minutes);*

 *(d)*

 2011

 7.3 *Organization.*

 *STEPS Country Reports.* 

97.9

52.1

 14.3

 33.0 *http://www.who.int/chp/steps/reports/en/.*

 *Last accessed on 21 May 2013.*

 3.8

 24.5

 0.6

18.9

38.1

24.2

 2008

 6.5

97.0

76.0

 14.4

 33.3

 4.6

 23.8

 1.0

16.6

46.8

23.7

 2010

 6.8

94.9

45.7

 6.2

 19.0

 2.6

 14.2

 2.4

13.1

23.7

16.1

*Lifestyle and Cardiovascular Risk Factors: Urban Population versus Rural Population…*

 2012

 14.1

97.2

32.4

 8.7

 26.0

 9.1

 26.0

 0.8

12.2

28.0

16.6

 2007

 7.1

87.4

49.3

 24.3

 36.0

 14.5

 5.8

 1.9

30.4

47.8

35.5

 2004

 22.2

 25.8

90.9

31.0

 7.8

 34.8

—

 —

1.4

22.7

37.2

27.0

78.8

73.5

 25.1

 39.6

 9.5

59.7

 4.2

29.9

52.1

38.8

 2007

 4.6

96.4

56.4

 3.2

 36.3

 22.5

—

0.9

17.5

26.8

21.4

 2005

 18.7

95.0

31.1

 7.5

 34.9

 3.8

2.1

 2.4

14.0

28.6

19.0

**Day2**


*Lifestyle and Cardiovascular Risk Factors: Urban Population versus Rural Population… DOI: http://dx.doi.org/10.5772/intechopen.96881*

> **Table 1.**

*compared to the rates observed in Western countries and a higher rate of a combination*

 *of RFs from 45 years.*

 *Prevalence of behavioral RFs and classical biological CVRFs according to STEPS studies [4].*

**Country**

**166**

 **Year1**

**%Who**

**% Who Ate**

**% Not Engaged**

**%**

**% With**

**% With**

**% With**

**% With**

**% With > 3 of**

**% With > 3 of**

**% With > 3 of**

**the CRFs, Ages**

**24–64 Years**

**Old**

**the CRFs, Ages**

**45–64 Years Old**

**Who**

**Raised**

**Raised**

**Raised Total**

**None of**

**the CRFs, Ages**

**in Vigorous**

**Physical**

**Are**

**Blood**

**Blood**

**Blood**

**the**

**25–44 Years Old**

**Cholesterol6**

**CRFs7**

**Obese3**

**Pressure4**

**Glucose5**

**Activity**

**Currently**

**< 5 Servings**

**Smoke**

**of F&V Per**

**Tobacco**

Benin

Botswana

Cameroon

Cape Verde

CAR

Chad

Comoros

Congo,

2005

 6.4

87.9

96.1

 5.8

 17.1

—

 —

5.3

19.9

34.0

24.1

*Lifestyle and Epidemiology - The Double Burden of Poverty and Cardiovascular Diseases…*

Dem. Rep.

Congo,

2004

 11.1

—

 —

8.6

 33.3

 20.8

——

 —

 —

 —

Brazzaville

Cote d'Ivoire

Eritrea

Ethiopia

Gabon

Gambia, The 2010

Guinea

Lesotho

Liberia

Madagascar

Malawi

Mauritania

 2006

 18.9

94.8

95.7

 20.9

 22.4

 6.2

 24.4

——

 —

 —

 2009

 14.1

97.5

17.8

 4.6

 32.9

 5.6

 2005

 19.6

62.0

75.1

 2.2

 35.8

—

 —

8.7

 1.0

13.0

23.7

16.5

12.8

12.1

17.7

13.8

 2011

 9.9

96.1

59.9

 22.0

 30.7

 19.2

—

1.1

28.7

43.2

33.5

 2012

 24.5

92.7

44.2

 19.9

 31.0

 6.3

4.6

 2.2

22.1

41.6

26.7

 2009

 12.8

79.3

52.3

 5.1

 28.1

 5.2

 2009

 12.1

 15.6

93.0

58.7

 12.1

 26.3

—

 —

9.8

 7.9

15.4

35.2

21.6

2.1

20.7

39.8

25.8

93.4

65.0

 15.9

 20.3

—

 —

1.2

30.0

50.0

36.4

 2006

 4.6

98.9

—

7.1

 30.9

—

 —

0.3

17.2

34.2

—

 2004

 7.8

98.1

83.9

 3.4

 16.6

—

 —

0.8

13.5

26.1

19.4

 2005

 14.4

83.5

93.0

 8.5

 25.9

—

 —

4.9

24.5

44.3

30.1

 2011

 12.9

85.7

61.7

 13.5

 25.4

 4.8

 25.9

 5.9

18.5

32.3

23.0

 2008

 11.2

84.8

74.0

 13.7

 27.6

—

 —

0.3

22.8

37.3

27.8

 2010

 14.1

66.1

55.6

 7.2

 34.5

 21.0

—

12.2

12.3

29.4

17.7

 2007

 9.9

 2003

 6.3

—

86.1

68.7

 10.5

 38.7

 12.7

 13.0

 5.0

84.3

 15.9

 17.3

 13.9

——

 —

19.6

41.8

24.8

 —

 —

 2007

 19.7

96.6

72.7

 15.6

 33.1

—

 —

1.2

25.7

50.4

34.5

 2008

 8.8

78.5

58.2

 9.4

 28.7

 3.0

7.9

 11.0

9.5

21.8

14.9

**Day2**

cardiomyopathy and coronary heart disease. In addition, rheumatic heart disease remains a worrying problem [5].

The **Tables 1** and **2** and **Figures 1** and **2** below relating to cardiovascular morbidity and mortality in SSA clearly illustrate the current place occupied by CVDs in this region of the world.

There are also a number of underlying determinants of CVDs. They stem from major social, economic and cultural developments - globalization, urbanization, aging populations, poverty, stress and hereditary factors [3]. It is these sociocultural and economic disturbances that could partly determine the differences observed between rural and urban areas in Africa.
