**5. Cardiovascular risk factors**

Many risk factors for CVD have been identified in the scientific literature and can be reversible or irreversible (**Table 1**). In 2016, 20% of the South African adults (15+ years) were smoking. [45] Risk factors present in the South African adult (18+ years) population are obesity (68% women; 31% men) hypertension (46% in women and 44% in men), [46] physical inactivity (37%), high blood pressure (24%) and hyperglycaemia (10%). [45] There is a paucity of national data for other CVD risk factors in adults, and very little CVD national data are available for children, except for the prevalence of overweight and obesity.

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


**Table 1.**

*Reversible and irreversible cardiovascular risk factors.*

#### **5.1 Socio-demographic risk factors**

The history of CVD of an individual is directly proportional to the risk of CVD (the earlier the age of onset and the more family members affected the greater is the risk of CVD). [47] It is known that men are at greater risk of developing CVD than women [47, 48] maybe because oestrogen has an inhibiting effect on low density lipoprotein-cholesterol (LDL-C) oxidation and increasing the production of large very low-density lipoproteins (VLDL) and therefore has a protective effect against atherogenesis. [50] Low levels of education in middle-income countries like SA had a significantly higher risk of major CVD events compared to those with high incomes. [49] The majority (>70%) of our communities showed low education (no or primary school education), [29, 31, 34, 35, 43] except for the peri-urban adults in the FS (44.2%); [44] and caregivers of the peri-urban children in Gauteng (39.9%), [29] however, these percentages are still high. High unemployment rates (53.0–94.0%) [29–31, 35, 44] for the majority of all the communities were also observed. The low education and high unemployment rates of the communities could be some of the main reasons for the high poverty rates in the study communities (67.7–100%). [26, 35, 36, 44] Research has found that people with low education may not have access to health care that may prevent detecting and treating disease and thus compromise their health even further. [50]

#### **5.2 Cigarette smoking**

Cigarette smoking doubles the risk of coronary artery disease and contributes seven-fold to the increase in risk for peripheral arterial disease. [51] Cigarette

**49**

*Double Burden of Poverty and Cardiovascular Disease Risk among Low-Resource Communities…*

Obesity is considered a multi-factorial condition [20, 53, 54] associated with an increased risk for comorbidities such as type 2 diabetes, insulin resistance, cancer, stroke, [53] hypertension, dyslipidaemia, [53, 55] and hypertriglyceridaemia. [55] Obesity is also considered an independent risk factor for CVD. [40] For every 1% increase above ideal body mass index (BMI), the cardiovascular risk (CVR) increases by 3.3% for females and 3.6% for males. [56] In our studies, the majority of the adults and elderly were overweight/obese. [44, 57] Although we did not report gender differences in this chapter, previous published results confirmed a higher prevalence among women in rural FS [37] and urban elderly [41] than in men. Our results further showed that the urban women in Gauteng had the highest prevalence (82.3%) of overweight/obesity, but cannot be compared to the periurban adults and urban elderly that included both men and women. However, the overweight/obesity prevalence among the urban elderly in Gauteng [57] and the peri-urban adults in the FS [44] was consistent with the national prevalence.

There is usually a higher prevalence of overweight/obesity in urban than rural.

[20] We did not have any rural adult communities to compare our results, but the urban elderly in Gauteng (61.0%) [57] had lower prevalence of overweight/ obesity than the peri-urban adults in the FS (67.9%). [44] This was inconsistent with research from sub-Saharan Africa (SSA) [54] and SA where it was found that age is positively correlated with overweight and obesity. [58, 59] In all three the adult communities, the prevalence of obesity was higher than the prevalence of overweight. (**Table 2**). The increasing prevalence of childhood overweight/obesity in SA [11] is presenting a major public health problem. Childhood overweight/ obesity is associated with early onset of hypertension and hyperglycaemia, both risk factors for CVD, [71] as well as adult obesity, [54] premature death and disability. [54] Similar to adults, a higher prevalence of overweight/obesity among children is found in urban areas. [54, 72, 73] (**Table 3**) However, our results showed higher prevalence among the rural children (4.3%) [24] compared to the urban children (1.0%). [32] In addition, the rural [28] and urban [32] children had the lowest prevalence of overweight and no obesity prevalence. Both peri-urban areas showed a prevalence of 21.0% in the FS [25] and 18.3% in Gauteng. [32, 33] This was higher than the national prevalence. In our studies among resource-poor communities, the prevalence of obesity was much lower than the prevalence of overweight. Our studies have found significantly higher prevalence of overweight/obesity in girls when compared to the boys. [24, 26] These results were consistent with national data [77] and for SSA, [54] but inconsistent with a recent systematic review and meta-analysis investigating overweight/obesity among 5–19 year old children in 15 countries in Africa where the boys and girls were equally affected by overweight/obesity. [71]. To summarise, overweight/obesity is common among the poor-resource adults

and elderly in our study population. The high prevalence observed among the adults, specifically women, and elderly may be due to poor nutrition (**Table 2**). Although the prevalence of obesity is not yet high among the children in our study

smoking and increases blood pressure and increases the heart's workload. It deprives the heart muscle of oxygen and damages the platelets that increase coagulation and clot formation. Toxins in cigarettes may also damage the blood vessels and increase atherosclerosis. [48, 52] In SA, the proportion of adult (15+ years) women that smoke (37%) daily is higher than in men (8%). [46] Smoking patterns among children were not measured in our studies, but we previously reported 11.7%, 15.2% and 23.6% smoking among urban elderly, [43] peri-urban adults in

*DOI: http://dx.doi.org/10.5772/intechopen.95992*

Gauteng [31] and rural adults in the FS. [37]

**5.3 Obesity**

*Double Burden of Poverty and Cardiovascular Disease Risk among Low-Resource Communities… DOI: http://dx.doi.org/10.5772/intechopen.95992*

smoking and increases blood pressure and increases the heart's workload. It deprives the heart muscle of oxygen and damages the platelets that increase coagulation and clot formation. Toxins in cigarettes may also damage the blood vessels and increase atherosclerosis. [48, 52] In SA, the proportion of adult (15+ years) women that smoke (37%) daily is higher than in men (8%). [46] Smoking patterns among children were not measured in our studies, but we previously reported 11.7%, 15.2% and 23.6% smoking among urban elderly, [43] peri-urban adults in Gauteng [31] and rural adults in the FS. [37]

#### **5.3 Obesity**

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

Genetically inherited factors

Hypertension Physical activity Hyperglycaemia, diabetes

Increased levels of homocysteine

Diet and dietary diversity

Stressful environment Personality types Geographic Climate and season (cold weather increased risk) Soft drinking water Environmental pollution

Increased inflammatory response (HS-CRP)

Increased haemostatic factors, decreased fibrinolysis, increased platelet

Dyslipidaemia (increased cholestrol, LDL, Triglyseride, decreased LDL)

Ageing

Obesity

aggregration

Irreversible Gender (male)

Potentially reversible factors Cigarette smoking

Psyschosocial Low socio-economic class

The history of CVD of an individual is directly proportional to the risk of CVD (the earlier the age of onset and the more family members affected the greater is the risk of CVD). [47] It is known that men are at greater risk of developing CVD than women [47, 48] maybe because oestrogen has an inhibiting effect on low density lipoprotein-cholesterol (LDL-C) oxidation and increasing the production of large very low-density lipoproteins (VLDL) and therefore has a protective effect against atherogenesis. [50] Low levels of education in middle-income countries like SA had a significantly higher risk of major CVD events compared to those with high incomes. [49] The majority (>70%) of our communities showed low education (no or primary school education), [29, 31, 34, 35, 43] except for the peri-urban adults in the FS (44.2%); [44] and caregivers of the peri-urban children in Gauteng (39.9%), [29] however, these percentages are still high. High unemployment rates (53.0–94.0%) [29–31, 35, 44] for the majority of all the communities were also observed. The low education and high unemployment rates of the communities could be some of the main reasons for the high poverty rates in the study communities (67.7–100%). [26, 35, 36, 44] Research has found that people with low education may not have access to health care that may prevent detecting and treating

Cigarette smoking doubles the risk of coronary artery disease and contributes seven-fold to the increase in risk for peripheral arterial disease. [51] Cigarette

disease and thus compromise their health even further. [50]

**48**

**5.2 Cigarette smoking**

**5.1 Socio-demographic risk factors**

*Reversible and irreversible cardiovascular risk factors.*

**Table 1.**

Obesity is considered a multi-factorial condition [20, 53, 54] associated with an increased risk for comorbidities such as type 2 diabetes, insulin resistance, cancer, stroke, [53] hypertension, dyslipidaemia, [53, 55] and hypertriglyceridaemia. [55] Obesity is also considered an independent risk factor for CVD. [40] For every 1% increase above ideal body mass index (BMI), the cardiovascular risk (CVR) increases by 3.3% for females and 3.6% for males. [56] In our studies, the majority of the adults and elderly were overweight/obese. [44, 57] Although we did not report gender differences in this chapter, previous published results confirmed a higher prevalence among women in rural FS [37] and urban elderly [41] than in men. Our results further showed that the urban women in Gauteng had the highest prevalence (82.3%) of overweight/obesity, but cannot be compared to the periurban adults and urban elderly that included both men and women. However, the overweight/obesity prevalence among the urban elderly in Gauteng [57] and the peri-urban adults in the FS [44] was consistent with the national prevalence.

There is usually a higher prevalence of overweight/obesity in urban than rural. [20] We did not have any rural adult communities to compare our results, but the urban elderly in Gauteng (61.0%) [57] had lower prevalence of overweight/ obesity than the peri-urban adults in the FS (67.9%). [44] This was inconsistent with research from sub-Saharan Africa (SSA) [54] and SA where it was found that age is positively correlated with overweight and obesity. [58, 59] In all three the adult communities, the prevalence of obesity was higher than the prevalence of overweight. (**Table 2**). The increasing prevalence of childhood overweight/obesity in SA [11] is presenting a major public health problem. Childhood overweight/ obesity is associated with early onset of hypertension and hyperglycaemia, both risk factors for CVD, [71] as well as adult obesity, [54] premature death and disability. [54] Similar to adults, a higher prevalence of overweight/obesity among children is found in urban areas. [54, 72, 73] (**Table 3**) However, our results showed higher prevalence among the rural children (4.3%) [24] compared to the urban children (1.0%). [32] In addition, the rural [28] and urban [32] children had the lowest prevalence of overweight and no obesity prevalence. Both peri-urban areas showed a prevalence of 21.0% in the FS [25] and 18.3% in Gauteng. [32, 33] This was higher than the national prevalence. In our studies among resource-poor communities, the prevalence of obesity was much lower than the prevalence of overweight. Our studies have found significantly higher prevalence of overweight/obesity in girls when compared to the boys. [24, 26] These results were consistent with national data [77] and for SSA, [54] but inconsistent with a recent systematic review and meta-analysis investigating overweight/obesity among 5–19 year old children in 15 countries in Africa where the boys and girls were equally affected by overweight/obesity. [71].

To summarise, overweight/obesity is common among the poor-resource adults and elderly in our study population. The high prevalence observed among the adults, specifically women, and elderly may be due to poor nutrition (**Table 2**). Although the prevalence of obesity is not yet high among the children in our study


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

#### **Table 2.**

*Cardiovascular risk factors in adults and elderly.*

communities, the results highlight the increasing burden of overweight among children (**Table 3**). The high prevalence of overweight and obesity in our study communities is a concern as the comorbidities associated with overweight/obesity have negative effects on health across the life cycle. [71]
