Abstract

Background

Diabetes is a major public health challenge in both developed and developing countries. Diabetes is a major risk factor for many cardiovascular diseases. It is associated with both genetic and environmental factor. This Risk factors are subdivided into modifiable, which are (Smoking, Drinking, Lifestyle, Diet, Lack of physical exercise) and non-modifiable factors which are family history, Age. The aim of this study was to determine the Angiotensin converting enzymes ( ACE)  genotype of  some BCH498 students associated with diabetes mellitus. ACE genes could either be insertion /insertion genes, deletion / deletion genes or insertion/deletion genes.

Materials and Methods

DNA was obtained from whole blood by DNA salting out method ( a non-enzymatic method of DNA extraction). A genotype method involving polymerase chain reaction (PCR) gel electrophoresis was used to obtained the genes. ACE Genes were amplified by PCR using primers, master mix, DNA template and deionized water, while agarose gel electrophoresis was used to determine  the genotypes.

Results  The study had  8 participants of some BCH498 students and it was expected that the insertion/deletion polymorphism will be more in the participants PCR products, indicating the presence of deletion (D) and insertion ( I) allele were  more clearly seen after electrophoresis on a 2 % agarose gel than the presence of insertion/deletion genes.

Conclusion The study included 8 participants and findings of the study shows that the deletion/deletion genes is more in the population than the insertion and insertion/deletion genes.

CHAPTER ONE

INTRODUCTION

  1.1 Background

Diabetes mellitus (DM) also known as hyperglycemia is a condition in which the pancreas does not produces enough insulin or the body is resistant to the insulin produced. According to the world health organization (WHO,2023), it is a chronic, metabolic disease characterized by elevated levels of blood glucose.

This chronic disease state over time will lead to serious damage to the heart, blood vessels, eyes, kidney and nerves. Normal levels of fasting blood glucose in the body is 100mg/dl (5.6mmol/L). Individuals with extremely high fasting blood glucose levels above 125mg/dl (7.0mmol/L) are considered diabetics as suggested by the Mayo Foundation for Medical Education and Research (MFMER, 2023).

Diabetes mellitus (DM) is a major risk factor for many cardiovascular diseases (CVD) and a major problem in developing countries including Cameroon and developed countries like Japan, Spain and American [Fan W,2017,Seurin etal.,2015]. (WHO,2023) report that over 422 million people worldwide have diabetes with majority in low and middle income countries.

According to WHO over the few decades in different parts of the world, the prevalence of DM has greatly increase. With the most recent data from the International Diabetes Federation (IDF), estimates had been made that over 382 million and 415 million adults of age 20-79years in 2013 and 2015 had diabetes worldwide.  In 2013 and 2015, it was foreseen that it will project to 592 million and 642million by 2035 and 2040, with  increasing  prevalence of 8.3-10.4%.

Despite this high prevalence seen in 2015, about 193 million people representing close to half of the population are still not aware of their disease states. Regionally, the age-adjusted prevalence of DM is 7.3% in Europe,  11.5% in North America and Caribbean, 9.6% in South and Central America, 9.1% in Southeast Asia,  8.8% in Western Pacific, 12.6% in Mexico, 16.8% in Egypt, 3.8% in Africa,  and 10.7% in Middle East and North Africa, [Fan, 2017; Seuring T et al., 2015]. In Cameroon, the prevalence is 5.5% as suggested by (KNOEMA, 2021) and also the prevalence of diabetes mellitus and prediabetes in Cameroon is 5.8% and 7.1% respectively [Jean J Bigna et al., 2018].

The three main types of diabetes are; the type one diabetes (T1D), type two diabetes (T2D) and gestational diabetes mellitus (GDM), with T2D as the most common. Other specific types like Neonatal diabetes (ND), and latent diabetes (LAD) do exist. The T1D is associated with autoimmune disorders of the pancreas. Diabetes mellitus is now term an epidemic, which is a major cause of death in USA  and the world at large. The causes of the different types of diabetes are genetics, epigenetic and environmental factors. The environmental factors are obesity, diet and physical activity.

Another cause of  T2D will result when the pancreatic beta cells no longer produces enough insulin to compensate for the insulin resistance  imposed in  increasing obesity [Fan W, 2017; Seuring T et al.,2015;Prasad R et al2015].  For T1D, another cause is destruction of the pancreatic beta cells responsible for insulin production. According to the (WHO, 2023), the number of death attributed to DM each year is 1.5 million. It is also a major risk factor for many cardiovascular diseases.

The pathogenesis of diabetes complications has not yet been clearly understood, but available data from multiple factors such as hemodynamic, alternations, metabolic abnormalities, variation growth factors and genetic factors has contributed greatly to the pathogenesis of diabetes. The genetic factor are genes involves the renin-angiotensin system.

Angiotensin-I converting enzyme (ACE) is one of the key enzyme in renin-aldosterone system (RAAS) and the insertion (I)/ deletion (D) polymorphism of the gene has been greatly studied. The genes are; two homozygous which are  insertion (I), and deletion (D) genes as well as heterozygous insertion (I)/ deletion (D) genes. The ACE is a membrane bound enzyme in the endothelial cells and in the different epithelial and neuro-epithelial cells, as well as circulating forms in biological fluid.

Cloning of the ACE  genes  made it possible to identify a 287 base pair insertion (I)/ deletion (D) genes polymorphism in intron 16(ACE I/D polymorphism) that appear to affect the level of serum ACE activity. Report shows that genotypes with deletion of 287 base pair result in a higher plasma ACE levels and hence individuals with homozygous for deletion had a greater serum ACE activity than those with homozygous insertion. The ACE I/D polymorphism has been  greatly studied since in 1990, and has been thought to be the marker for functional polymorphism which regulates circulating and tissue ACE  activity [Ha S, et al., 2014].

Guidelines have been put by the American Heart Association (AHA) and American Diabetes Association (ADA) to prevent the cardiovascular diseases (CVD). According to them, the primary way of preventing CVD of people with diabetes is by focusing on the lifestyle, BP control, blood glucose control, physical activity, and taking a good diet [Fan W,2017 ].

Sarcopenia is a syndrome characterized by progressive and generalized degenerative loss of skeletal muscle mass (SMM), quality and strength, occurring during normal ageing and many chronic diseases. In addition to the muscle loss, sarcopenia patient are at a high risk of having fracture bones and falls. Old people with diabetes are twice more likely to develop sarcopenia. Treatment of this condition is done using insulin therapy, metformin, thiazolidinedione, Dipeptidyl peptidase IV inhibitors and sodium glucose co-teansporter 2  inhibitor  [Zhang, X et al., 2021].

1.2  Problem Statement

Diabetes is a major public health problem globally. The prevalence of diabetes has greatly increased worldwide over the last decades, due to rise in T2D.

Studies shows that the pathogenesis of this drastic complication is not clearly understood, but available data suggest that multiple factors such as metabolic abnormalities, growth factors and genetic factors contributes to this pathogenesis [Ha et al., 2014].

1.3 Rational

Diabetes is a worldwide public health problem and a risk factor for most cardiovascular (CVD) diseases. This problem is seen in both developed and developing countries like Cameroon. From recent epidemiology studies, report shows that the prevalence of diabetes in Cameroon is 5-6% of the total population.

Some studies have shown an association homozygous deletion genotype with T1D and T2D. This study is aimed at identifying the different ACE genotypes of some BCH498 students. This will help the students to know if they are susceptible to diabetes or not and also help create awareness about the life style modifications to put in place in order to prevent diabetes.

1.4 Hypothesis

Insertion (I)/ deletion (D) polymorphism of the ACE genes are associated with plasma ACE levels and individuals with the homozygous deletion (D) alleles have been reported to be more susceptible to diabetes.

1.5 Objectives

1.5.1 General Objectives

To identify the different genotypes of some BCH498 students associated with diabetes.

1.5.2 Specific Objectives

1. To collect blood samples from some BCH498 students
2. To extract DNA from the blood sample collected
3. Amplifier the DNA and  run

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