Several studies in different population indicate that inflammation may be the link between obesity, insulin resistance and cardiovascular disease. However, this relationship has not been adequately explored in our population and among Africans with increasing high rate ofobesity and IR. In this study, the association between obesity markers (Body mass index, waist circumference, and waist-hip ratio), inflammatory marker (Tumour necrosis factor-alpha), insulin resistance markers (Homeostasis model assessment of insulin resistance, insulin) and markers of cardiovascular risks (Atherogenic index of plasma, lipid profile, blood pressure) were evaluated in a total of one hundred and sixty subjects (160). One hundred and ten (110) of which were obese subjects (BMI 30kg/m2 and above) and fifty (50) non-obesecontrols. Blood pressure and fasting samples were collected. Anthropometric parameters were measured; body mass index and waist-hip ratio were calculated for all the participants recruited in this study. Obese subjects were further grouped based on their BMI values as; class I (BMI 30-34.9kg/m2), class II (BMI 35-39.9kg/m2) and class III (BMI 40kg/m2 and above). TNF-α and insulin were determined using enzyme linked immunosorbent assay (ELISA). Total cholesterol and triglyceride were determined using the enzymatic colorimetric method; LDL, VLDL, HOMA-1R, AIP were respectively calculated. High density lipoprotein was determined using the precipitation/cholesterol enzymatic method. The mean values of TNF-α, insulin, FPG, HOMA-1R, TC, TG, LDL, VLDL, AIP, SBP and DBP were all significantly higher in obese subjects compared to non-obese controls group (P<0.05). The mean value of HDL was significantly higher in the non-obese controls compared to the obese group (P<0.05). The values of WHR, TG, VLDL, DBP and AIP were significantly higher in male obese subjects compared to obese female (P<0.05). No significant differences were observed in the other parameters in the male and female obese participants. There were no significant variations in the levels of TNF-α, TC, TG, HDL, LDL, VLDL and AIP among the three groups (P>0.05). Insulin and HOMA-1R were significantly higher in class III group compared to the class I group. A significant positive correlation was observed between obesity markers (BMI, WC) and markers of insulin resistance (HOMA-1R, insulin) among the obese subjects (P<0.05).
Table of Contents
1 INTRODUCTION
1.1 Background to the study
1.2 Statement of the problem
1.3 Aim and objectives of the study
1.3.1 Aim
1.3.2 Specific objectives
1.4 Justification of the study
2 LITERATURE REVIEW
2.1 Obesity
2.2 Classification of obesity
2.3 Prevalence of obesity
2.4 Causes of obesity
2.5 Effects of obesity on health
2.6 Management of obesity
2.7 Obesity and metabolic syndrome
2.8 Insulin
2.8.1 Synthesis, physiological effects and degradation of insulin
2.8.2 Insulin signal transduction pathway
2.9 Obesity and insulin resistance
2.10 Homeostasis model assessment of insulin resistance
2.11 Adipose tissue cellularity and changes with obesity
2.11.1 White Adipose Tissue
2.11.2 Brown Adipose Tissue
2.12 Mechanism of free fatty acid mediated insulin resistance
2.13 Obesity induced inflammation and insulin resistance
2.13.1 Obesity induced macrophage accumulation in the adipose tissue
2.14 Role of adipose tissue produced adipokines in insulin resistance
2.14.1 CCL2/MCP-1 and other chemokines
2.14.2 Interleukin-6
2.14.3 Leptin
2.15 Tumour necrosis factor –alpha
2.15.1 Structure of TNF-α
2.15.2 TNF-α cell signaling
2.15.3 Role of adipose tissue produced TNF-α in insulin resistance
2.16 Overview of lipid metabolism
2.16.1 Intracellular and extracellular transport pathway
2.16.2 Reverse cholesterol transport pathway
2.17 Obesity and dyslipidemia
2.18 Role of adipose tissue produced adipokines in dyslipidemia
2.19 Cardiovascular diseases
2.19.1 Risk factors for cardiovascular disease
2.19.2 Symptoms of cardiovascular diseases
2.19.3 Inflammation and cardiovascular diseases
2.20 Obesity, inflammation and cardiovascular diseases
2.20.1 Risk factors as biomarkers
2.21 Disorder of Lipid Metabolism
2.21.1 Chylomicron syndrome
2.21.2 Familial Hypercholesterolaemia
2.21.3 Familial Hypertriglyceridaemia
2.21.4 Dysbetalipoproteinaemia (Type III hyperlipoproteinaemia)
2.21.5 Familial Combined Hyperlipidaemia
2.21.6 Hyperapobetalipoproteinaemia
2.21.7 Hypoalphalipoproteinaemia
2.21.8 Hypobetalipoproteinaemia
2.21.9 Secondary hyperlipideamia
3 MATERIALS AND METHODS
3.1 Subject selection
3.1.1 Inclusion criteria
3.1.2 Exclusion criteria
3.2 Anthropometric measurements
3.3 Sample collection
3.4 Determination of fasting plasma glucose
3.5 Determination of insulin
3.6 Determination of Tumour-necrosis factor alpha (TNF-α)
3.7 Determination of total cholesterol concentration
3.8 Determination of Triglyceride concentration
3.9 Determination of High density lipoprotein cholesterol concentration
3.10 Calculation of very low density lipoprotein cholesterol concentration
3.11 Calculation of low density lipoprotein (LDL) cholesterol concentration
3.12 Calculation of Homeostatic model assessment of insulin resistance (HOMA-IR)
3.13 Calculation of atherogenic index of plasma (AIP)
3.14 Statistical Analysis
4 RESULTS
5 DISCUSSION AND CONCLUSION
5.1 Discussion
5.2 Conclusion
5.3 Contribution to knowledge
5.4 Recommendations
Research Objectives & Topics
The primary aim of this study is to investigate and provide information on the association between various obesity markers, such as BMI and waist circumference, inflammatory markers like TNF-alpha, insulin resistance markers including HOMA-IR and insulin, and cardiovascular risk factors among obese individuals in Calabar, Nigeria.
- Association between obesity markers and insulin resistance.
- Role of TNF-alpha in obesity-related inflammation.
- Evaluation of cardiovascular risk markers in obese subjects.
- Comparative analysis of insulin resistance across different obesity classes.
- Investigation into gender-based differences in metabolic parameters.
Excerpt from the Book
1.1 Background to the study
Obesity is an important contributor to ill health and is now so common in our population that it is beginning to relieve undernutrition as a major disease that affects health (Tsigosa et al, 2008). Worldwide, obesity ranks second after smoking as the cause of avoidable deaths and its prevalence is increasing in children and adults.Authorities view it as one of the most serious public health problem of the 21st century (Barness et al, 2007).
“Obesity results from the accumulation of excessive body fat that often presents a risk to health” (WHO, 2014).The state of one being obese is usually defined using body mass index (a ratio of the weight in kg and the square of height in meters of an individual) (Kamazawa et al, 2002). Body mass index of 30kg/m2 and above marks obesity, while the range of 25-30kg/m2 is defined as overweight (Barness et al, 2007).
Over 60million fully grown individuals in the U.S. have been identified as been obese with BMI of 30kg/m2 and above, also surprizing is the fact that the prevalence of obesity has steadily gone up to30% during the past decade (Flegal et al, 2002). Often thought to be a challenge only in countries with high income, overweight and obesity are now also gradually increasing in developing countries and is affecting the general world population (WHO, 2009). Here in Nigeria, the prevalence of overweight individuals has been reported to range from 20.3% to 35.1%, 8.1% - 22.2% for obesity (Chukwuonye, 2013).
Summary of Chapters
1 INTRODUCTION: This chapter outlines the global and local prevalence of obesity and establishes the scope of the study regarding insulin resistance and cardiovascular risk factors.
2 LITERATURE REVIEW: This chapter provides an extensive overview of obesity, insulin resistance, lipid metabolism, inflammation, and cardiovascular diseases, grounding the study in existing scientific literature.
3 MATERIALS AND METHODS: This chapter describes the study population, participant selection, anthropometric measurements, and biochemical analysis techniques utilized for collecting and testing data.
4 RESULTS: This chapter presents the statistical data comparing obesity, insulin resistance markers, and cardiovascular risk factors between obese and non-obese subjects.
5 DISCUSSION AND CONCLUSION: This chapter interprets the findings, discusses their implications in the context of previous studies, and provides recommendations based on the research outcomes.
Keywords
Obesity, Insulin Resistance, Cardiovascular Disease, TNF-alpha, HOMA-IR, Body Mass Index, Dyslipidemia, Adipose Tissue, Inflammation, Triglycerides, HDL, LDL, Atherogenic Index, Metabolic Syndrome
Frequently Asked Questions
What is the core focus of this thesis?
The work examines the relationship between obesity and metabolic health, specifically looking at how inflammatory markers and obesity indicators predict insulin resistance and cardiovascular risk in a specific Nigerian population.
What are the central thematic fields?
The study centers on Chemical Pathology, focusing on the pathophysiology of obesity, the role of pro-inflammatory cytokines like TNF-alpha, and lipid metabolism.
What is the primary research goal?
The primary goal is to determine the association between obesity markers (BMI, WC, WHR), inflammatory markers, and cardiovascular risk factors among obese individuals in Calabar.
What methods were employed for data collection?
The researcher used a study cohort of 160 volunteers (110 obese, 50 control), collecting fasting blood samples to determine glucose, insulin, TNF-alpha, and lipid profiles using ELISA and enzymatic colorimetric methods.
What is addressed in the main body?
The main body covers the theoretical background of obesity, its physiological impact on insulin sensitivity, the mechanisms of lipid dysregulation, and the specific methodology used to quantify these variables.
Which keywords best characterize this research?
The most defining keywords include Obesity, Insulin Resistance, Cardiovascular Disease, TNF-alpha, HOMA-IR, and Metabolic Syndrome.
How is HOMA-IR used in this study?
HOMA-IR (Homeostasis model assessment of insulin resistance) is calculated from fasting insulin and glucose levels to classify participants into different degrees of insulin resistance.
What role does TNF-alpha play in the findings?
The study explores TNF-alpha as a potential proinflammatory marker linking adipose tissue accumulation to insulin resistance and cardiovascular disease.
How does obesity affect lipid profiles according to the text?
The text explains that obesity-related dyslipidemia is characterized by higher triglycerides, reduced HDL levels, and changes in LDL composition, which collectively increase the atherogenic index of plasma.
- Citation du texte
- Chidozie Agu (Auteur), 2016, Tumour Necrosis Factor Alpha and Atherogenic Index as Predictors of Insulin Resistance and Risks of Cardiovascular Disease among Obese Subjects in Calabar, Nigeria, Munich, GRIN Verlag, https://www.grin.com/document/342187
