**2. What is dyslipidaemia in children?**

From a general biology perspective, lipids are organic and water insoluble compounds which include fatty acids, triglycerides, and cholesterol. Lipoproteins are also soluble in watery environments of human body. Chylomicrons are formed in the intestine after fat is digested. They are then moved to the fat tissue, muscle, and liver. Chylomicrons are hydrolysed into free fatty acids and then metabolised to low density lipoprotein cholesterol (LDL-C) (the major carrier of cholesterol to tissues). Cholesterol is a fatty substance that passes through high density lipoprotein cholesterol (HDL-C) to peripheral tissues and then to the liver. Abnormalities in the pathway lead to dyslipidaemia.

Dyslipidaemias are lipoprotein metabolism disorders that result in the abnormalities of high total cholesterol (TC), high LDL-C, high non-HDL-C, high triglycerides, and low HDL-C. The HDL and LDL cholesterol monitor the amount of cholesterol that can occur in the body, and if there is an excess it can increase the risk of cardiovascular events. Other forms of dyslipidaemia also include high phospholipids and combined dyslipidaemia.

Since cholesterol is an essential component of human cells, cholesterol may also be generated by individual cells or introduced to the body via our diets. However, when cholesterol levels are increased for whatever reason, they may be bad for the human body. Lipid levels in children younger than 19 years of age are different from lipid levels in adults and vary for the same age in different patients. As an infant, the levels of cholesterol and triglycerides are lower than when a person is an adult. Levels grow steadily during the first year of adolescence, then increase more slowly until they reach the age of 9 to 11 years, but then increase slightly faster until they reach adulthood. At puberty, low-density lipoprotein cholesterol (LDL-C) blood levels decrease by about 10% to 20% or more, whereas high-density lipoprotein (HDL-C) levels increase by 50% or more.

The plasma levels of serum lipids and lipoproteins as recommended are in **Table 1**. Normative data are used to establish cut-off points and identify ranges of acceptable, borderline, and abnormal levels as shown. In **Table 1**, the values for plasma lipid and lipoprotein levels are taken from the National Cholesterol Education Program's (NCEP) Expert Panel on Cholesterol Levels in Children as they were observed. Non-HDL-C values from the Bogalusa Heart Study are equivalent to the NCEP Paediatric Panel cut-off points for LDL-C. Values for plasma Apo B and Apo A-1 come from the National Health and Nutrition Examination Survey III (NHANES III). As a usually occurring wide range, the threshold points for high and borderline-high values reflect roughly the 95th and 75th percentiles, respectively. These values fall into the range of the 10th percentile of the standard range for HDL-C and ApoA-1. It should be noted that the ranges for plasma lipoprotein cholesterol in **Table 1** are consistent with the guidelines of the National Heart, Lung and Blood Institute, the American Academy of Paediatrics and the American

**111**

200 mg per dL [16].

*Dyslipidaemia in African Children and Adolescents DOI: http://dx.doi.org/10.5772/intechopen.96804*

**mg/dL (mmol/L)**

**Category Acceptable**

children's population.

TG

**Table 1.**

**3. Problem of dyslipidaemia in children**

*adolescents, national heart, lung, and blood institute [3].*

College of Cardiology. However, these cut-off points have not been validated as accurate benchmarks for accelerated atherosclerosis and CVD events in the African

*Acceptable, borderline-high, and high plasma lipid and lipoprotein ranges for children and adolescents.*

TC <170 (4.4) 170 to 199 (4.4 to 5.2) ≥200 (5.2) LDL-C <110 (2.8) 110 to 129 (2.8 to 3.3) ≥130 (3.4) Non-HDL-C <120 (3.1) 120 to 144 (3.1 to 3.7) ≥145 (3.8) ApoB <90 (2.3) 90 to 109 (2.3 to 2.8) ≥110 (2.8)

0 to 9 years <75 (0.8) 75 to 99 (0.8 to 1.1) ≥100 (1.1) 10 to 19 years <90 (1 mmol/L) 90 to 129 (1 to 1.5) ≥130 (1.5) HDL-C >45 (1.2) 40 to 45 (1 to 1.2) <40 (1) ApoA-1 >120 (3.1) 115 to 120 (3 to 3.1) <115 (3) *Adapted from expert panel on integrated guidelines for cardiovascular health and risk reduction in children and* 

**Borderline mg/dL (mmol/L)**

**High mg/dL (mmol/L)**

Atherosclerosis and cardiovascular disease (CVD) are the major health problems associated with dyslipidaemia. These disorders are vascular problems associated with more than 17 million deaths worldwide in 2015, a rise of 12.5 per cent from 2005 onwards [9]. While it is acknowledged that a diet low in saturated fat and regulated cholesterol levels are essential for heart health, it is also determined that certain foods can increase the risk of coronary artery disease (CAD) and other cardiovascular problems [10–12]. Although the prevalence of dyslipidaemia has gradually decreased in several high-income and developing countries over the last 20 years, it is currently predicted that the incidence of dyslipidaemia will increase in African countries due to

As far back as 1981, evidence from different studies among Caucasians showed that in childhood, serum levels of cholesterol and triglycerides could rise to levels similar to those seen in young adults at around 2 years of age [14]. Concentrations and turnover of such important molecules in blood lipid concentrations do occur in children. Over the years, researchers have found that if there is a family history of

There is ample evidence which suggests that there are more children and adolescents with the hyperlipidemia disease. From the 1988–1994 National Health and Nutrition Survey, it was shown that 10 percent of teenagers had the total cholesterol greater than 200 mg per dL [15]. Also, the newly generated age- and gender-specific lipoprotein from data of the Child and Adolescent Trial for Cardiovascular Health showed that over one-tenth of children aged 9 to 10 years had TC levels greater than

While data on the severity of dyslipidaemia among children and adolescents in Africa are scarce in published literature, a few observational studies have reported hypercholesterolemia prevalence and associated risk factors. In the Ghana School Survey conducted in two cities, Kumasi and Accra, the proportion of children with

the rapid change in lifestyles to high-income and developed countries [13].

CVD, there is greater concern that a CVD will be developed.

#### *Dyslipidaemia in African Children and Adolescents DOI: http://dx.doi.org/10.5772/intechopen.96804*


*Adapted from expert panel on integrated guidelines for cardiovascular health and risk reduction in children and adolescents, national heart, lung, and blood institute [3].*

#### **Table 1.**

*Management of Dyslipidemia*

that the incidence and prevalence of obesity and dyslipidaemia is on the rise in the population of African children and adolescents, partially due to shifts in economic and lifestyle towards the trends in the Western world [8]. Serious comorbidities, complications, and cardiovascular risk factors, including obesity, diabetes mellitus, hypertension, and smoking, are correlated with dyslipidaemia. As a result, more attention tends to be paid to the increasing problems of dyslipidaemia among the African population in recent years. The key objectives of this chapter are to discuss the burden of dyslipidaemia, diagnosis, risk factors and health problems, as well as

gaps in awareness of dyslipidaemia in children and adolescents in Africa.

From a general biology perspective, lipids are organic and water insoluble compounds which include fatty acids, triglycerides, and cholesterol. Lipoproteins are also soluble in watery environments of human body. Chylomicrons are formed in the intestine after fat is digested. They are then moved to the fat tissue, muscle, and liver. Chylomicrons are hydrolysed into free fatty acids and then metabolised to low density lipoprotein cholesterol (LDL-C) (the major carrier of cholesterol to tissues). Cholesterol is a fatty substance that passes through high density lipoprotein cholesterol (HDL-C) to peripheral tissues and then to the liver. Abnormalities in the

Dyslipidaemias are lipoprotein metabolism disorders that result in the abnor-

Since cholesterol is an essential component of human cells, cholesterol may also be generated by individual cells or introduced to the body via our diets. However, when cholesterol levels are increased for whatever reason, they may be bad for the human body. Lipid levels in children younger than 19 years of age are different from lipid levels in adults and vary for the same age in different patients. As an infant, the levels of cholesterol and triglycerides are lower than when a person is an adult. Levels grow steadily during the first year of adolescence, then increase more slowly until they reach the age of 9 to 11 years, but then increase slightly faster until they reach adulthood. At puberty, low-density lipoprotein cholesterol (LDL-C) blood levels decrease by about 10% to 20% or more, whereas high-density lipoprotein

The plasma levels of serum lipids and lipoproteins as recommended are in **Table 1**. Normative data are used to establish cut-off points and identify ranges of acceptable, borderline, and abnormal levels as shown. In **Table 1**, the values for plasma lipid and lipoprotein levels are taken from the National Cholesterol Education Program's (NCEP) Expert Panel on Cholesterol Levels in Children as they were observed. Non-HDL-C values from the Bogalusa Heart Study are equivalent to the NCEP Paediatric Panel cut-off points for LDL-C. Values for plasma Apo B and Apo A-1 come from the National Health and Nutrition Examination Survey III (NHANES III). As a usually occurring wide range, the threshold points for high and borderline-high values reflect roughly the 95th and 75th percentiles, respectively. These values fall into the range of the 10th percentile of the standard range for HDL-C and ApoA-1. It should be noted that the ranges for plasma lipoprotein cholesterol in **Table 1** are consistent with the guidelines of the National Heart, Lung and Blood Institute, the American Academy of Paediatrics and the American

malities of high total cholesterol (TC), high LDL-C, high non-HDL-C, high triglycerides, and low HDL-C. The HDL and LDL cholesterol monitor the amount of cholesterol that can occur in the body, and if there is an excess it can increase the risk of cardiovascular events. Other forms of dyslipidaemia also include high

**2. What is dyslipidaemia in children?**

phospholipids and combined dyslipidaemia.

(HDL-C) levels increase by 50% or more.

pathway lead to dyslipidaemia.

**110**

*Acceptable, borderline-high, and high plasma lipid and lipoprotein ranges for children and adolescents.*

College of Cardiology. However, these cut-off points have not been validated as accurate benchmarks for accelerated atherosclerosis and CVD events in the African children's population.

### **3. Problem of dyslipidaemia in children**

Atherosclerosis and cardiovascular disease (CVD) are the major health problems associated with dyslipidaemia. These disorders are vascular problems associated with more than 17 million deaths worldwide in 2015, a rise of 12.5 per cent from 2005 onwards [9]. While it is acknowledged that a diet low in saturated fat and regulated cholesterol levels are essential for heart health, it is also determined that certain foods can increase the risk of coronary artery disease (CAD) and other cardiovascular problems [10–12]. Although the prevalence of dyslipidaemia has gradually decreased in several high-income and developing countries over the last 20 years, it is currently predicted that the incidence of dyslipidaemia will increase in African countries due to the rapid change in lifestyles to high-income and developed countries [13].

As far back as 1981, evidence from different studies among Caucasians showed that in childhood, serum levels of cholesterol and triglycerides could rise to levels similar to those seen in young adults at around 2 years of age [14]. Concentrations and turnover of such important molecules in blood lipid concentrations do occur in children. Over the years, researchers have found that if there is a family history of CVD, there is greater concern that a CVD will be developed.

There is ample evidence which suggests that there are more children and adolescents with the hyperlipidemia disease. From the 1988–1994 National Health and Nutrition Survey, it was shown that 10 percent of teenagers had the total cholesterol greater than 200 mg per dL [15]. Also, the newly generated age- and gender-specific lipoprotein from data of the Child and Adolescent Trial for Cardiovascular Health showed that over one-tenth of children aged 9 to 10 years had TC levels greater than 200 mg per dL [16].

While data on the severity of dyslipidaemia among children and adolescents in Africa are scarce in published literature, a few observational studies have reported hypercholesterolemia prevalence and associated risk factors. In the Ghana School Survey conducted in two cities, Kumasi and Accra, the proportion of children with hyperlipidemia was 12.1% for TC, 4.5% for TG, 28.4% for HDL-C and 9.2% for LDL-C [17]. Another study conducted among adolescent school children in the Eti-Osa Local Government Area of Lagos State, Nigeria, recorded that only 3.6 per cent of participants had TC greater than 200 mg/dL [18]. The highest prevalence of high TC among Angolan pre-pubertal adolescents, 7 to 11 years of age, was estimated to be 69.2% [19].
