The History, Etiology, and Epidemiology of Type I and Type II Diabetes, Research Paper Example
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Diabetes is a chronic illness that has plagued humanity for thousands of years. For centuries the presence of diabetes in a patient was typically only recognized by evidence of some of its symptoms, and there was little awareness of or distinction between the different types of diabetes that are now recognized today. Despite the fact that diabetes has been recognized for millennia, it is only in the last 100 years that any effective treatments were identified and developed to combat the disease. With very rare exceptions, there is no cure for diabetes; the condition can typically be treated and managed with exercise, proper diet, and medications. Diabetes is present in millions of people throughout the world, and the prevalence of the disease is growing in some regions. The following discussion will examine the history, etiology, epidemiology, and treatment of diabetes, and will consider those factors that are contributing to the current prevalence and spread of the disease.
History of Diabetes
15 centuries B.C.E. the ancient Egyptians wrote about the symptoms of diabetes, describing the condition as “too great emptying of urine” (Furdell, 2009). For hundreds of years to come various observations and proclamations would be made about the various conditions collectively known as diabetes, though few of these would have any significant basis in medical reality. Along with these inaccurate and incomplete assessments of what constituted diabetes, a wide range of treatments were prescribed, few of which had any legitimate medical benefit or, really, and positive effect at all on sufferers of diabetes. It was not until the early 20th century when insulin was developed for the treatment of diabetes that the medical community was able to prescribe any effective treatment for the condition.
Furdell uses the example of Great Britain and the history of the disease in that country as a case study for understanding the historical context of diabetes. Like many Western nations, Britain made the transition from a largely agrarian society to a largely industrial and technological society over the last several centuries. As this transition was underway, the prevalence of diabetes in the British population rose in conjunction with the social and cultural changes wrought by industrialization. It is now understood that there are connections between diet and the development of Type II diabetes; the advent of the dietary changes associated with the development of industrial societies is believed to correlate to the rise in the number of cases of diabetes throughout the world. Simply put: as societies become industrialized, the number of cases of diabetes increases.
As was the case with the ancient Egyptians, ancient Hindus also identified the symptoms of diabetes among some sufferers. A number of these symptoms were used to describe or name the condition; in most cases the observers of the presence of diabetes made note of the excessive thirst and the need for frequent urination among those with the disease. Other ancient observations about diabetes included the fact that the urine produced by some diabetics would attract insects, and often tasted sweet (because of the excess of sugars being expelled from the body in the urine). This led to an association of diabetes with honey; the term “mellitus,” which was eventually added to the term “diabetes,” literally means “of honey”(Alberti and Viberti, 1992). Despite the range of observations made about the symptoms and presentations of diabetes, little was known about the causes of or treatments for either Type I or Type II diabetes; there were few, in fact, who identified a distinction between the two conditions until relatively recently.
An ancient Indian physician did describe some sets of symptoms of diabetes that appeared to afflict patients differently; he was, in effect, describing the difference between “juvenile diabetes” and “adult-onset diabetes,” though no actual distinction was made indicating that these were two different disorders with different causes (Furdell). For much of Western history post-B.C.E., there were few who even drew those distinctions, or who demonstrated any significant understanding of diabetes, its causes, or its treatment. As was the case with most medical disorders, physicians in the Middle Ages believed diabetes was caused by an imbalance of bodily humors, and the treatment for the condition typically involved the administration of various herbs and other botanicals believed to counteract or offset these supposed imbalances. As would be expected, such “treatments” were useless, and many diabetics with Type I diabetes died not long after their first symptoms presented themselves.
Diabetes was recognized and described in various parts of the world; by the early centuries A.D. observers in China, Greece, Rome, and the Middle East were leaving written records of such observations. In most instances the focus of these descriptions, and often the names the observers applied to the condition, were related either to the excessive thirst seen in diabetics, or to the sugars present in the urine of diabetics. The ancient Indian name for diabetes, mudhema, literally means “honey urine” (Furdell); the Chinese descriptions and labels for diabetes developed in the third century A.D. are focused on the unquenchable thirst of sufferers.
Throughout the centuries of the first millennium A.D. a variety of treatments were offered to sufferers of diabetes. Islamic physicians prescribed remedies of various combinations of ground-up plants and minerals, as did ancient Byzantine and British physicians. The entirety of such treatments was largely based on a complete misunderstanding of human physiology, and none had any significant positive effect. Physicians in medieval Britain and Europe, heavily influenced by religion, often associated illness of any kind with moral and spiritual issues, and believed that sufferers of diabetes and other diseases had behaved in ways that brought their diseases upon themselves (Furdell). Such incomplete and inadequate approaches to understanding and treating diabetes continued for centuries; in some cases, physicians managed to identify the kidneys as being associated with diabetes, though such information was inevitably uncoupled from any effective approach to the treatment of the disease.
Despite the lack of adequate or appropriate treatments for diabetes throughout much of the last two millennia, there are examples of ancient medical texts that do a fair job of identifying the symptomatic expressions of diabetes. Over the course of nearly 4000 years of written records related to diabetes, however, little more than such descriptions were developed to explain the disease; even the distinction between the various types of diabetes was not discovered until the early 20th century. It was in this period that the most rapid acquisition and development of information related to diabetes and its treatment occurred, and much of the predication for current understanding and treatment of diabetes was borne from this era.
Etiology of Diabetes
It was at the turn of the 20th century that the first significant breakthroughs were made in terms of understanding, and later treating, diabetes. Researchers working with experimental animals found connections between pancreatic activity and the onset of diabetes. The existence of insulin was first inferred by researchers around the turn of the century, but would not be positively identified for two more decades. Continued study of diabetes in the early part of the 20th century would convince researchers that it was a manageable condition in many cases, but the underlying causes and the physiological mechanics of the disease were poorly understood. It was not until the 1930s that a clear distinction was made between Type I and Type II diabetes; further distinctions about the causes that underpinned each of these two types were yet to come.
The earliest distinctions between the two types of diabetes were based largely on the ages of sufferers; the types were commonly referred to as “juvenile diabetes” and “adult-onset diabetes” (Ekoe et al, 2008). It was not well-understood in these early years of the 20th century that the two conditions had different underlying causal factors; the distinction between the age groups was, at least to a degree, believed to explain the different manifestations of symptoms and effect on patients. It would eventually be discovered that so-called “juvenile diabetes” was predicated on the body’s inability to produce insulin in sufficient levels, while “adult-onset diabetes” demonstrated a physiological resistance to insulin, a condition that is currently often treated with medications that circumvent such resistance. Insulin deficiencies are sometimes present in patients with adult-onset diabetes as well, and in such cases treatment of the disease must be adapted accordingly.
Diabetes must be understood as a set of conditions; further, these conditions can and do have different physiological and environmental causes (Ekoe et al). Contemporary understanding of diabetes recognizes that it involves a complex intersection of factors and demonstrates a wide variety of manifestations. At its core, diabetes is characterized by a state of hyperglycemia (Ekoe et al), though the underlying causes of this state, and the effects that such hyperglycemia may have on a patient’s physiology, are shaped by a number of different forces and factors. For some patients the predicating physiological conditions are congenital; for others, diet and other environmental factors can contribute to the onset of hyperglycemia. For many patients, the state of hyperglycemia may go unnoticed for years, and may cause little damage or significant damage to the patient’s bodily systems in that time.
Type I diabetes –formerly known as “juvenile diabetes”- is characterized by an inability of the body to produce insulin. Insulin, along with other chemicals produced by the body, helps to regulate metabolism and manage the utilization of sugars in food. When insulin is present in insufficient quantities, the body cannot properly metabolize sugars, and these sugars then build up in the bloodstream. Type I diabetes is believed to be a manifestation of an autoimmune disorder; in short, the body destroys the cells in the pancreas that produce insulin, either limiting or eliminating insulin production. Other hormonal and physiological activities in the body can conflict with the ability of insulin to regulate the metabolism of sugars, further complicating the picture of what causes diabetes and what sets of conditions constitute the disease.
Juvenile diabetes can be present at birth, or can begin to develop in childhood, during puberty, or even later. The factors that trigger the underlying autoimmune functions of Type I diabetes are not well-understood; researchers posit that triggers may include various viruses, allergic reactions to foods or other environmental factors, or may simply be congenital. Regardless of the specific cause in each patient, or of the specific manifestations of symptoms of diabetes, there are a few underlying processes affected by the action of Type I diabetes. The lack of insulin during metabolism leads the body to react inappropriately to sugars present in food. Instead of properly storing or burning off these sugars, they are pumped into the circulatory system as if they are needed for short-term energy, such as the body might require during a shortage of food. In short, the body reacts to the lack of insulin in much the same way as it would react to a period of starvation, despite the presence of food in the body.
This disruption of the normal metabolic process produces a number of common symptoms; the excessive thirst and excessive hunger seen among diabetics throughout history are caused by this disruption. As sugars flood the circulatory system, the body sheds some of the excess sugar through frequent urination; this is what drives the unquenchable thirst in untreated diabetics. The metabolic dysfunction also drives the excessive hunger of Type I diabetics; despite having an increased appetite, Type I diabetics often experience physical wasting because they cannot properly metabolize not just sugars, but other components of food such as fats and proteins. Patients with Type I diabetes generally require regular injections of insulin in order to offset the potential damage caused by the disease.
Type II diabetes, formerly referred to as adult-onset diabetes, is the more common form of the condition (Ekoe et al). It is generally caused when the body develops an inability to properly manage its use of insulin. Type II diabetes is often predicated by obesity and issues related to poor diet. In most cases, patients with Type II diabetes are capable of producing insulin; in fact, there is often an overproduction or irregular production of insulin present. The various signals sent by metabolic hormones become disrupted, and the proper management of sugars becomes impossible. Type II diabetes can be more insidious than Type I diabetes; sufferers of Type II diabetes may have the condition for many years without knowing it. As the condition worsens, the potential damage caused by a constant state of hyperglycemia may continue, causing problems in the circulatory system and other associated problems. Type II diabetes can often be managed through changes in diet or with the administration of medications that assist the body with proper regulation of insulin and other metabolic hormones.
Epidemiology of Diabetes
As noted previously, the underlying causes and contributing factors to Type I diabetes are still not well-understood. The commonality of hyperglycemia between Type I and Type II diabetes was, for several decades, the primary consideration for researchers attempting to draw a clear picture of the epidemiology of the disease (Alberti and Viberti). The World Health Organization (WHO) has published several reports on diabetes; two of the most notable of these reports were published in 1965 and in 1980. It was the latter report that delved more deeply into the distinctions between Type I and Type II diabetes, and also discussed sub-classifications of the disease, such as “gestational diabetes” and other manifestations of metabolic disorders that gave rise to hyperglycemia (Ekoe et al).
Much of the emphasis on the epidemiological understanding of diabetes has focused on Type II diabetes (Wild et al, 2004). This focus is understandable for several reasons; first, it is the most common form of the disease; second, it is closely associated with potentially-manageable environmental factors such as diet and exercise; third, it has been conclusively linked with a number of social and cultural factors. This last point is, perhaps, the most significant one to consider when examining the epidemiology of Type II diabetes. Type II diabetes has been closely associated with the so-called “Western diet,” i.e.- many the dietary patterns seen in industrial societies are directly linked to Type II diabetes (Ekoe et al). A similar correlation is seen in societies that are in a state of transition towards industrialization and modernization; as this transition continues, the number of cases of Type II diabetes grows accordingly (Clark et al, 2009). Researchers believe they have identified some of the factors that link the “Western diet” and Type II diabetes, though the picture is far from complete. What is clear is that the epidemiology of Type II diabetes is inextricably linked with the phenomena associated with industrialization and modernization; if nothing else, such links provide researchers with viable starting points when developing studies and experimental models related to diabetes.
Perhaps the most obvious connection between Type II diabetes and the Western diet (this term will be used for the remainder of the discussion as a catch-all phrase to describe the variety of factors associated with industrialization/modernization and their effects on dietary and other lifestyle factors) is in the association between the disease and obesity (Wild et al). The move from an agrarian society to an industrial society often brings concomitant dietary and lifestyle changes, most notably in terms of a shift towards including greater amounts of animal proteins and fats in the more “modern” diet (Ekoe et al; Alberti and Viberti). A diet heavy on fruits and vegetables, and lighter on animal proteins and facts, is generally considered to underpin good health in most people. The Western diet often includes copious amounts of fast food and other heavily-processed food, much of which is laden with fats and sugars. In the U.S., for example, researchers describe the Western diet as being largely responsible for the epidemic of obesity seen over the last several decades. Along with the problems associated with the Western diet, industrial and modernized societies often allow (or even force) many members of the population to lead sedentary lifestyles.
Simply put: the farmer who lives in an agrarian society spends much of his or her time engaging in physical labor, and often has access to a diet that includes a variety of fruits, grains, and vegetables. An office worker in an industrial society may spend most of his or her workday sitting at a desk, stopping just long enough to eat fast food or other heavily-processed food before returning to the desk. Couple these factors with the stresses and anxieties of the fast-paced modern world, and it is easy to see how the Western diet –and the associated lifestyle factors- could and does contribute to obesity and a range of other health-related issues. While researchers do not claim to fully understand exactly why Type II diabetes is spreading so rapidly in the industrialized world, it is quite understandable that many have posited clear links between the Western diet and the disease.
A report published by the WHO in 2004 attempted to take a snapshot of the prevalence of diabetes on a global scale, and to offer a projection for coming decades about the spread and growth of the disease. Both Type I and Type II diabetes were examined and discussed; not surprisingly, the WHO report projected significantly-higher rates of growth and prevalence for Type II diabetes, asserting that the link between the condition and the Western diet would become exponentially more significant as globalization fomented increasing industrialization in the developing world (Wild et al). The WHO report offered a number of observations about the global scale of diabetes; among them were the assertion that 2.8% of the world’s population had diabetes in the year 2000, and that such a figure will nearly double by the year 2030. Other observations include the fact that diabetes is more prevalent in men, but there are currently more women than men who actually have the disease. The WHO report claims that the leap in the percentage of the world’s population with diabetes will be directly linked to the shifting demographics of the modern age. According to the report “the urban population in developing countries is projected to double between 2000 and 2030” (Wild et al); with it, the prevalence of diabetes will grow accordingly.
When discussing the issue of diabetes, and the factors that are likely to underpin the increases in the prevalence of the disease in coming decades, it may be helpful to frame such a discussion in the theoretical context of the political economy-model. This framework allows for consideration of the economic forces of capitalism that drive the industrialization of the developing world. The changing conditions wrought by industrialization have been clearly linked to a rise in the prevalence of diabetes, and the projections by the WHO and other researchers show that this link will continue to drive up the numbers where diabetes and other health-related issues are concerned.
The rapid rise in the rate of obesity in Western/industrialized societies is not limited to the lower socioeconomic classes, though there is evidence that the increase in obesity rates is higher among such classes (Clark et al). As nations throughout the developing world become increasingly industrialized, the number of people who adhere to the Western diet, and who also adhere to the lifestyle factors associated with it, will continue to increase. While the WHO predicts a small percentage-rate bump in the number of people with Type I diabetes in the coming decades, the most significant increase will likely be seen in terms of Type II diabetes. It seems clear that this is not just a physiological issue; it is in fact virtually impossible to separate the rising prevalence of Type II diabetes from the social, political, and economic factors that contribute to it. It is also clear that there is little evidence that the increasing prevalence of Type II diabetes is avoidable; as long as the drive towards industrialization continues at its current rate, so too will the number of people with diabetes grow accordingly. Although Type II diabetes is often avoidable and even more often manageable, the conditions in place that have established the basis for the growing epidemic are, according to all the available evidence, neither avoidable nor manageable.
Alberti, K. G., & Viberti, G. (Ed.). (1992). International textbook of diabetes mellitus: Volume 1. Chichester, UK: Wiley.
Clark, L. et al (2009). Cultural Values and Political Economic Contexts of Diabetes Among Low-Income Mexican Americans. Journal of Transcultural Nursing, 20(4), 382-394.
Ekoé, J. M., Rewers, M., & Williams, R. (Ed.). (2008). The Epidemiology of Diabetes Mellitus. Hoboken, NJ: Wiley.
Furdell, E. L. (2009). Fatal thirst: Diabetes in Britain until insulin. Leiden, UK: Brill.
Wild, S. et al (2004). Global Prevalence of Diabetes: Estimates for the year 2000 and projections for 2030. Diabetes Care, 27(5), 1047-1053.
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