BC is a term used to mean ” Before Christ” and AD is the chronological dates after the birth of Christ and stands for ” Anno Domini”. Over the past several centuries, our human behaviour and surrounding environment has changed significantly and as a result this has directly impacted our mortality and morbidity rates caused by specific diseases. Cardiovascular diseases are the leading global killers contributing to the highest mortality rates than any other disease, an example is coronary heart disease (CHD) resulting in problems with the blood vessels supplying the heart and initiated by a build up of fatty acids within the inner walls of the blood vessels. Cardiovascular disease accounts for 1 in 3 deaths in the UK and the World Health Organisation predicts that CHD will continue to radically rise by 2030 so it is important that we make changes in our lifestyle to protect our health. In the early stages of CHD there is a build up of cholesterol-rich deposits in the arterial wall, high blood cholesterol levels also known as hypercholesterolaemia, is a form of metabolic stress and can result in the narrowing of the arterial lumen due to plaque formation. Thrombosis occurs in the final stage of blockage of the blood vessel and this happens due to a number of events such as the development of a solid mass from the constituents of blood and adherence of platelets to the endothelium, platelet-fibrin thrombus, platelet aggregation resulting in blood clot formation and changes in blood flow, when the heart’s blood supply is interrupted chest pain known as angina can occur (WHO, 2012). High levels of low-density lipoproteins (LDL), smoking, unhealthy diet high in saturated fats and high blood pressure are risk factors for CHD and many studies have shown high levels of high-density lipoproteins (HDL) are not related with CHD deaths. Modern day work related stress such as working longer hours, increased workload demands and occupational hazards such as chemical, biological, physical or ergonomic have been known to exacerbate or in fact cause cardiovascular disease and it is evident that both men and women are working harder than ever in this day and age (Price, 2004). Untreated hypertension can be dangerous to the cardiovascular system, a normal blood pressure reading for a 20 year old and older should be below 120/80 mmHg, high blood pressure is diagnosed at anything above 140/90 mmHg (NHS Choices, 2012). If high blood pressure is not treated it can lead to the enlargement of the heart and potentially cause heart failure or a heart attack (BBC Health, 2013).
Table: Deaths by sex and cause, 2010, England
Cardiovascular disease71, 97975, 342Coronary heart disease37, 87327, 370Stroke15, 78824, 709Other cardiovascular disease18, 31823, 263All other causes51, 21867, 104
222, 366238, 651Figure 1: The table taken from British Heart Foundation Statistics Factsheet (2012) shows figures of CHD death rates in the UK and mortality rates caused by other diseases, CHD deaths are higher in males than females a reason for this is the difference in sex hormones, women primarily produce estrogen and this is found to have a significant outcome on the function of endothelial cells which play a crucial role in the development of atherosclerosis and estrogen also has antioxidative properties as well as being capable of lowering blood lipids and producing cardioprotective effects from glucose metabolism (Jousilahti et al, 1999). Atherosclerosis occurs in the innermost layer of the arterial wall known as the intima and it is the chronic inflammation of susceptible sites in the artery wall and results from plaque formation of cells, it requires many years even decades to develop and is started off by damage to the endothelium layer which can be caused by viral infection, toxins or metabolic strain. Atherosclerotic plaque is often advanced from fatty streak lesions, T lymphocytes are found in the intima layer and they are a main attribute of atherosclerotic lesions, but the exact role they play in atherosclerosis process is still uncertain (Pockley, 2002). The plaque is a thickened area on the intima made up of fibrous protein, it is formed by monocytes attaching to the endothelial lining the endothelial cells are then stimulated by slightly oxidised LDL to let loose cytokines, here cytokines make monocytes convert into macrophages which present receptors to engulf the oxidised LDL, these oxidised LDL induce endothelial cell damage. The macrophages full with cholesterol become foam cells; these are inflammatory cells and cluster together amid the endothelium and muscle layer. Connective tissue matrix production as well as build of lipid and macrophages contributes to the development of atherosclerotic lesions. C-reactive protein (CRP) is a indicator for inflammatory stimulation and is found in the blood, however it is still not clearly known if CRP contributes to the atherosclerosis process and therefore a risk factor for heart disease or whether is simply a sign of CHD (Makover, 2011). High concentrations of oxidised cholesterol can cause death to nearby cells and the vast build up of cholesterol in the artery causes inflammation, tissue damage and fibroproliferative scars, the intima has no lymphatic vessels to get rid of excess proteins that seep out of the endothelial layer this is why LDL levels are highest in this type of connective tissue than any other found in the body. The plaque can rupture at any time on the inside of the artery and this allows the blood to come into direct contact with the cholesterol which then quickly forms a clot called a thrombus, this then ultimately leads to a stroke or heart attack (Guyton, n. d.). CHD is evident by a range of symptoms caused by a fibrous plaque partially or completely blocking the coronary arteries, the more enlarged a plaque size is, the greater obstruction of the artery. The rate of plaque formation increases with risk factors such as diabetes mellitus, smoking, hypertension and obesity (Insull Jr. 2009). Physiological stresses such as oxidative injury and genetic mutations brings about changes in a cell when they respond to a type of stress, eventually the function and structure of a protein changes with this response. Heat shock proteins (HSP) are molecular chaperones which are active in cellular processes they provide cytoprotection, involve corrective protein folding, repair denatured proteins or induce degradation. HSP are also involved with cell survival in cardiac diseases. Although HSP provide positive aspects to cells certain HSP have also been linked to the pathogenesis of cardiovascular disease, a particular study showed raised antibodies levels to the bacterial HSP60 in elevated serum levels in patients suffering from cardiomyopathy; activated T-cells recognise HSP60 as an antigen and therefore can cause an autoimmune disease (Benjamin & McMillan, 1998).
Unhealthy Diet – Consequences for Health
In the Western culture typically people eat an atherogenic diet, rich in cholesterol and saturated fats. Excess sugar, excess sodium, fast food, trans fat and processed food are common in western diet, all these can contribute to heart disease and have serious consequences for our health. The occurrence of oxidative modified low density lipoproteins (oxLDL), high triglycerides, high LDL levels and low levels of HDL cholesterol are associated with increased risk of CHD, oxLDL are cytotoxic to the endothelial cells and can cause cellular changes in smooth muscle cells and macrophages (Bird, 2013). A study conducted by Rimm et al (1993) found an association linking high intake of vitamin E and decreased risk of CHD in men, vitamin E is an antioxidant and found in many healthy foods, foods that were perhaps eaten more often in BC than in AD and now more people are found to be deficient in several vitamins including vitamin E which could suggest an explanation to the increase in CHD amongst people today. There is evidence to suggest that environmental and genetics are contributory factors and there is an inherited predisposition to developing the disease, fat metabolism is influenced by genes and some people may be more inclined to developing CHD than others. People suffering from CHD should try to manage the disease through a healthy lifestyle which includes a balanced diet and exercise, although cases of obesity were prevalent in the years of BC, it is becoming more of a problem for health in today’s Western culture; the US has shown a dramatic rise in obesity over the last 20 years with unhealthy behaviour and lack of physical activity to blame, gradually more adolescents are becoming obese this is resulting in more health implications, people who are overweight or obese are at higher risk of developing CHD and diabetes mellitus (a risk factor for CHD), causing an increase in morbidity and mortality rates in recent decades, this would not have been a major concern in the years ” before Christ” where there were basic food portions and simple agriculture. Increase of high glucose levels in the bloodstream caused by an unhealthy diet or those suffering from diabetes mellitus, can go on to develop fatty acids called atheroma to accumulate within the artery walls, as this hardens it forms a plaque which can subsequently lead to death of cardiac cells as a result of a myocardial infarction. Diet related chronic diseases were not a major issue many centuries ago, human lifestyle back then was very different to what it is today hunting was the main source of food and even harvesting simple crops and selling them by trade, today food is more easily accessible and no longer scarce although famine and poverty still occurs in poor countries but nowadays people simply buy food at grocery supermarkets, people also work in offices, institutes or buildings to earn a living this modern day work ethic has led to decreased movement and lack of exercise and hence high blood pressure.
Alcohol and Smoking – Consequences for Health
Drinking large amounts of alcohol causes blood pressure to rise via the kidneys and blood vessels, frequent drinking can also lead to weight gain which can cause high blood pressure, a risk of CHD and heart attacks, binge drinking can also cause irregular heartbeats. Alcohol when drunk is absorbed into the bloodstream and broken down by an enzyme called alcohol dehydrogenase (ADH) in the liver and converted to acetaldehyde the first metabolite product, it is known to have toxic properties. Alcohol abuse has had more of an effect in AD years than BC, more young people are dying from alcohol abuse and it is linked to several developmental and social concerns, a problem which may have had no concern in BC. Life expectancy is further increasing; more people are living older in 2013 AD than they were in BC and mortality rates in developed countries are somewhat declining due to modern medicine slowing down the progression of disease (Howse, 2006). Cigarette smoking and tobacco use can cause CHD and increase the chances of lung cancer, cigarette smokers double their risk of stroke as it causes the narrowing of blood vessels especially the arteries which reduces circulation, stroke happens when the brains blood supply is obstructed, damaging the brain cells. When smoke in inhaled adrenaline is produced by the body which is stimulated by nicotine, this causes the heart to beat quicker and blood pressure to rise so the heart has to work harder than normal. In tobacco smoke the carbon monoxide has a negative impact on the heart because it reduces the bloods capacity to carry oxygen by attaching itself to haemoglobin; the oxygen carrier protein in red blood cells, consequently this lessens the availability of oxygen to the tissues, this puts the smoker at risk of developing atherosclerosis which can result in a stroke or myocardial infarction. Another effect of smoking is it increases blood cholesterol levels and fibrinogen amounts; this causes the blood to become stickier as platelet aggregation increases. Platelet aggregation is the process of non-covalent bridging of αIIbβ3 integrin receptors (Jackson, 2007).
Infections – Consequences for Health
Cases of sexual transmitted infections (STIs) have doubled in recent decades, although STIs existed in BC they were not as prevalent as they are today due to more people practicing risky sexual behaviour and having more than one sexual partner, in the UK chlamydia is the most frequently diagnosed STI (HPA, 2013). Many studies have presented an association between Chlamydia pneumoniae infection, CHD and atherosclerosis; one particular study showed C. pneumoniae was regularly identified in the atheromatous plaques of several post-mortem bodies in their coronary arteries so chlamydia is shown to be a risk factor to CHD (Thomas et al, 1999). C. pneumoniae has been found to provoke an immune response by producing HSP60 through infection; a study conducted by Deniset et al (2010) found C. pneumoniae caused structural changes and thickening of the arterial vessel and showed major increase of HSP60 expression. To end with, a combination of environmental agents, genetic susceptibility and behavioural factors all contribute and suggest an explanation for the increase of CHD in people today than in BC. High blood pressure can run in family history so it is linked to genetic factors but also lifestyle choices such as high alcohol intake and drinking frequently is an influencing risk factor to cardiovascular disease, the risk of suffering from CHD also increases with age. Inheritance and genetic predisposition are important factors in the risk of CHD, African American women are more prone to high blood pressure, high cholesterol, obesity and diabetes than white women and these are all risk factors for CHD, so race can also potentially be a risk factor for the likelihood of CHD (American Heart Association, 2010). In AD the advances made in understanding the pathogenesis of CHD has led to more successful diagnostic and treatment methods, something which was considerably lacking in BC years although science has significantly developed since then, mortality rates for CHD are still high. Currently the inflammatory marker, C-reactive protein can reasonably predict CHD in people this will allow better diagnoses and may prevent heart attacks and stroke from happening in the future although further research still needs to be investigated (Danesh et al, 2004). Access to healthcare has improved since BC and the healthcare in general as we have acquired more knowledge regarding CHD than people knew in BC. In BC era more natural organic food was eaten as this was easily accessible although organic processed food did exist back then it was not as readily consumed as it is today or as popular, so CHD was not a major problem because people were eating fresh fruit and vegetables and were more active compared with people today who are eating more processed food in AD which contains high sodium contents, a contributing factor that leads to obesity. Today tobacco use and smoking is still common even though the health problems associated with it such as heart disease are common knowledge, something which would not have been known in BC, chances of getting CHD can be reduced by simply giving up smoking and drinking alcohol, increasing physical activity and eating a healthier diet.
World Health Organisation (2012). Cardiovascular diseases (CVDs). [Online] Available from: http://www. who. int/mediacentre/factsheets/fs317/en/index. html – [Accessed on 2nd February 2013]Price, A. (2004) Heart disease and work. National Center for Biotechnology Information. [Online] 90(9): 1077–1084. Available from: http://www. ncbi. nlm. nih. gov/pmc/articles/PMC1768437/ – [Accessed on 13th February 2013]NHS Choices (2012). Diagnosing high blood pressure. [Online] Available from: http://www. nhs. uk/Conditions/Blood-pressure-(high)/Pages/Diagnosis. aspx – [Accessed on 23rd February 2013]BBC Health (2013). High blood Pressure. [Online] Available from: http://www. bbc. co. uk/health/physical_health/conditions/in_depth/heart/hypertension1. shtml – [Accessed on 23rd February 2013]Figure 1 taken from: British Heart Foundation (2012). Coronary heart disease statistics in England. [Online] Available from: http://www. bhf. org. uk/plugins/PublicationsSearchResults/DownloadFile. aspx? docid= e3b705eb-ceb3-42e2-937d-45ec48f6a797&version=-1&title= England+CHD+Statistics+Factsheet+2012&resource= FactsheetEngland – [Accessed on 6th March 2013]Jousilahti et al (1999). Sex, Age, Cardiovascular Risk Factors and Coronary Heart Disease. Circulation Journals. [Online] 99: 1165-1172. Available from: http://circ. ahajournals. org/content/99/9/1165. full – [Accessed on 13th March 2013]Pockley, G (2002). Heat Shock Proteins, Inflammation and Cardiovascular Disease. Circulation Journals. [Online] 105: 1012-1017 Available from: http://circ. ahajournals. org/content/105/8/1012. full – [Accessed on 13th March 2013]Makover, M (2011). C-reactive protein. U. S. National Library of Medicine. [Online] Available from: http://www. nlm. nih. gov/medlineplus/ency/article/003356. htm – [Accessed on 12th March 2013]Guyton, J. (n. d.). Atherosclerosis – a story of cells, cholesterol and clots. [Online] Available from: http://classes. biology. ucsd. edu/bisp194-2. WI11/Guyton%20article. pdf – [Accessed on 12th March 2013]Insull Jr. (2009). The pathology of atherosclerosis: plaque development and plaque responses to medical treatment. PubMed. [Online] Available from: http://www. ncbi. nlm. nih. gov/pubmed/19110086 – [Accessed on 12th March 2013]Benjamin & McMillan (1998) Stress (Heat Shock Proteins). Circulation Journals. [Online] 83: 117-132 Available from: http://circres. ahajournals. org/content/83/2/117. full. pdf+html – [Accessed on 13th March 2013]Rimm, E et al (1993). Vitamin E Consumption and the Risk of Coronary Heart Disease in Men. The New England Journal of Medicine. [Online] 328: 1450-1456. Available from: http://www. nejm. org/doi/full/10. 1056/NEJM199305203282004 – [Accessed on 6th March 2013]Jackson , S. (2007) The growing complexity of platelet aggregation. Journal of the American Society of Hematology. [Online] vol. 109 no. 12 5087-5095. Available from: http://bloodjournal. hematologylibrary. org/content/109/12/5087. short – [Accessed on 6th March 2013]Sue Bird (2013) Atherosclerosis an Immune Disorder. SHS80304-6 [Lecture Notes] Biomedicine. Staffordshire University. Science Building. Room R002. 31st January 2013. Howse, K (2006) Increasing Life Expectancy and the Compression of Morbitidity. [Online] July 2006. Available from: http://www. ageing. ox. ac. uk/files/workingpaper_206. pdf – [Accessed on 13th February 2013]Health Protection Agency (2013). Sexually Transmitted Infections. [Online] Available from: http://www. hpa. org. uk/Topics/InfectiousDiseases/InfectionsAZ/STIs/ – [Accessed on 12th March 2013]