**5. Risk factors for CVD among adolescents and youths**

#### **5.1 Unhealthy diets**

A host of CVDs has been related to behavioral risk factors such as smoking, excessive alcohol intake, lack of physical exercise, and a high cholesterol diets, age and family history [55, 56]. According to Odunaiya et al. [17], poor dietary habits were widespread among Nigerian teenagers, with low fruit and vegetable intake leading the list, followed by high saturated fatty diets. The trend can be traced to western leisure standards adopted by the majority of the Nigerian populace, as well as major modifications in the quality, content, and quantity of meals consumed, particularly with the expansion of fast-food restaurants [57–59]. Furthermore, the CVD attributable risks at adolescence can either persist into adulthood or turn out to be a considerable predictor of future cardiovascular events, as studies [28, 60] have shown that CVD has its foundations in childhood and adolescence, with variables linked to dietary choices and physical activity, being crucial antecedents of hypertension and obesity. Yilgwan et al*.* [61] observed high levels of obesity, physical inactivity, hypertension, and dyslipidemia in primary school children, with the pointers dominated by undernutrition. Diet has a significant impact in defining CVD risk factors, and consumption of a diet heavy in saturated fat, particularly palmitic acid, raises total cholesterol and LDL-cholesterol levels [62, 63].

Trans-fatty acids, which are found in relatively high concentrations in processed hydrogenated oils and dairy products common in Nigerian stores and markets, can

#### *Prevalence and Risk Factors of Cardiovascular Diseases among the Nigerian Population: A New… DOI: http://dx.doi.org/10.5772/intechopen.108180*

increase CVD risk by increasing LDL cholesterol and decreasing HDL cholesterol [64]. According to Oguoma et al*.* [42], high alcohol intake can be connected with a statistically significant risk of hypertension. Similarly, Reynolds et al*.* [65] found that high alcohol use elevates the incidence of stroke in a meta-analysis. Alcohol intake in Nigeria was previously regulated by customs and traditions [66], but this has changed owing to changes brought about by economic development and westernization. Males are also more likely to consume alcohol than females, according to a WHO report, with 5% of males and 1% of females in Nigeria being regular alcohol consumers [67]. Major cooking oils in Nigeria are palm oil and groundnut oil, which are locally produced and sold at markets. Because these low-cost oils are widely available, people consume them regularly, which contributes to the rise in obesity, metabolic syndrome, and type 2 diabetes [68, 69]. Palm oils are produced locally, but foreign or well-processed groundnut oils, if accessible, are very costly [70].

According to WHO/FAO standards, saturated and monounsaturated fatty acid consumption must not surpass limits of 10% and 15–20%, respectively, to maintain proper total cholesterol levels and lower the risk of CVD [69, 71]. The consumption of fats and oils in Nigeria is an essential subject of research that must be investigated given the constantly growing occurrences of metabolic syndrome and diabetes in the populace.

#### **5.2 Alcohol, tobacco, and other drugs**

Harmful use of alcohol and tobacco smoking are established risk factors for the incidence of cardiovascular diseases [1], and studies have also found that all subgroups of recreational drugs are independently associated with a higher likelihood of heart diseases [72]. Over the years, research has found an association between heavy alcohol consumption and tobacco smoking with conditions and events such as hypertension, cardiomyopathy, ischemia, peripheral artery disease, and increased risk of hemorrhage in the blood vessels [73–76]. However, the link between use of some drugs and cardiovascular diseases (CVDs) have not always been clear cut, and some researchers have identified that light to moderate consumption of alcohol might be a protective factor against some cardiovascular conditions like stroke [77]. The reason for this controversy is down to the fact that unlike in other scientific studies in which randomized control trials are the gold standard for concluding causation, it is impractical or even unethical in most cases to use a randomized control trial to investigate whether or not an association exists between drug use and cardiovascular diseases; hence, some uncertainty remains with respect to the causal relationship between some of these drugs, the volume consumed, and the incidence of CVD [78]. Tobacco smoking however has consistently been shown to be linked with heart diseases as seen in longitudinal and cross-generational studies like the British Doctor study and the Framingham Heart study [79, 80].

There has been a rise in CVD in developing countries like Nigeria, with a high mortality rate among young people than in developed countries [81], and this has been linked with both novel and traditional risk factors. One of which is the use of alcohol, tobacco products, and other drugs, which have been shown to be on an upward trajectory among youths in Nigeria, and statistics by the Nigerian Drug Law Enforcement Agency (NDLEA) estimates that about 40% of the country's youths are deeply involved in the use of drugs, with alcohol as the most used substance and cannabis as the most commonly abused illicit drug [82]. The United Nations Office of Drug and Crime [83] has also established that the use of drugs among youths between the ages of 15 and 39 years in Nigeria is high and young people are initiated into use of illicit drugs like cannabis at an average age of 19 years. Using drugs from a young age is associated with poor health outcomes over the long term, and those youths who use four or more psychoactive substances have an increased risk of developing premature atherosclerotic cardiovascular diseases [72]. Although manifestations of CVD mostly occurs in adulthood, risk factors such as drug use develop during adolescence and youth, a critical stage of development, characterized by distinct physical, psychological, cognitive, and social changes [84]. The emergence of CVD among Nigerian adolescents and youths may reflect an increase in the volume and potency of drug use among young people. This increase as described by Dumbili [85] is a result of the normalization of drug use among young people in Nigeria.


#### **Table 2.**

*Genes that cause cardiovascular diseases.*

*Prevalence and Risk Factors of Cardiovascular Diseases among the Nigerian Population: A New… DOI: http://dx.doi.org/10.5772/intechopen.108180*

The 2020 World Drug Report projects the use of drugs among young people to grow in the next decade [86], particularly in low- and middle-income countries, and this will pose more threats to the cardiovascular health of these youngsters. Fortunately, drug use is a modifiable risk factor; thus, it can be prevented and controlled by strengthening early detection [17] and modifying health behavior of young people through adequate health information and health promotion programs designed to improve young people's knowledge and attitudes toward drug use and CVD prevention.

#### **5.3 Genetics**

There are multiple causes of cardiovascular diseases, but there is no uncertainty that genetic factors play a crucial role in their development (**Table 2**).

Cardiovascular diseases outcomes in a general population can be complicated by several genetic variables. The study of atypical mendelian types of variations, whereby mutations in single genes create dramatic outcomes, has proved extremely beneficial. These mutations provide a biological framework for understanding CVD development [88]. Mutations in genes that influence certain mechanisms have been found in families with inherited cases of hypertension or hypotension, both are caused by irregularities in the functioning of aldosterone synthase, and this has been observed to be an autosomal dominant trait which is characterized by hypertension, repressed renin activity, and abnormal aldosterone levels. This is induced by an unbalanced overlap between genes encoding enzymes of the adrenal-steroid biosynthesis pathway [89]. Hypertrophic cardiomyopathy is the most prevalent monogenic heart disorder and the leading cause of mortalities from cardiac abnormalities in children and adolescents, with an estimated 1 in 500 people suffering from the condition [90]. The heredity of hypertrophic cardiomyopathy is autosomal dominant in nature, and the condition is associated with mutations of genes that code for proteins in the myocardial contractile apparatus [91].

Arrhythmia predisposing genes have been identified and studied to provide further insight into the molecular pathobiology of arrhythmias [92]. Correspondingly, Gellens et al. [93] reported the SCN5A gene to encode subunits that form Na+ channels, which is responsible for triggering cardiac action potentials. SCN5A mutations give rise to a number of hereditary arrhythmias, including long-QT syndrome, idiopathic ventricular fibrillation, and cardiac-conduction disorders [94].
