Research Paper 1: Diabetes Mellitus

Lieberman, Leslie Sue Lieberman. “Diabetes.” Credo Reference Home. Cambridge University Press, n.d. Web. 13 Apr. 2013. <http://www.credoreference.com/topic/diabetes

Diabetes mellitus (DM) is an endocrine disorder characterized by the lack or insufficient production of insulin by the pancreas. Insulin, a hormone produced in the pancreas by the islets of Langerhans regulates the amount of glucose in the blood. The lack of insulin causes a form of diabetes. DM has been recognized as a disease for at least two millennia, but only since the mid-1970s has there been a consensus on its classification and diagnosis. Symptoms include excessive urination, urine containing sugar, hunger, thirst, fatigue, and weight loss, are common to all types of DM.

The primary diagnostic criterion for DM is elevation of blood glucose levels during fasting or at 2 hours following a meal. Normal plasma glucose values for adults in the fasting state are 80–120 milligrams per deciliter (mg/dL). Definition of unequivocal DM requires a 2-hour postingestion plasma glucose level equal to or greater than 200 mg/dL for the appearance of classical symptoms of diabetes. Despite the use of a plethora of different terms in the past, diabetes is now generally classified as type I DM (insulin-dependent diabetes) and type II DM (non-insulin-dependent diabetes). Other variants of DM include maturity-onset diabetes of youth, tropical diabetes, which shows characteristics of both insulin dependence and nondependence, and gestational diabetes, which occurs during the latter part of pregnancy. Approximately 90–95 percent of all diabetics may be classified as type II, and about 5 percent as type I. Some 2 percent of diabetics have DM as a secondary result of other disease or injury.

Insulin-Dependent Diabetes Mellitus (Type I) Insulin-dependent DM is characterized by clinically acute onset, usually at an early age, reduction in the production and excretion of insulin, weight loss, thirst, frequent urination, and high levels of blood sugar. Some nutritional factors have been suspected of being involved in the etiology of type I diabetes, although there is no consistent picture. There is strong evidence for a genetic susceptibility, but of those individuals who carry the suspected antigens, only 30–50 percent develop DM; thus, environmental factors also appear to have a role. A number of studies indicate an increased prevalence of type I diabetes among populations that previously showed low rates. Excess caloric intake does not seem to be the important factor it is in type II diabetes. Typical type I diabetes is uncommon, affecting less than 0. 5 percent of the world’s population. Other possible causative factors include infectious viruses such as mumps, rubella, and meningitis. In general, these increases are associated with a “Westernization” of lifestyle since World War II.

Type 1 Diabetes

Abundant worldwide evidence associates obesity with type II diabetes, and experts have concluded that it is the most powerful risk factor for non-insulin-dependent DM. However, it is difficult to disentangle the effects of decreased fiber consumption from increased sugar and carbohydrate intake, increased total calories, total fat, decreased caloric expenditure, and stresses associated with rapid dietary change and modernization. Conversely, during World War I and II in Europe and during World War II in Japan, when caloric intake was markedly decreased, obesity and diabetes both declined. It has been suggested that dietary fiber decreases the risk for diabetes, and different forms of fiber are being investigated in this connection. Genetic mechanisms interacting in complex ways with environmental factors are involved in the risk for type II diabetes. Diabetes rates have increased in a number of countries, such as Japan, Taiwan, Haiti, New Guinea, and parts of Africa, where caloric consumption per capita has also increased. Many causative factors have been implicated in type II diabetes and many observations have been made on sex differences in the frequency of type II diabetes. Most researchers agree that there is no convincing evidence that a single dietary component increases the risk of diabetes. More recent studies documented high frequencies of both obesity and diabetes among a number of Amerindian tribes in Oklahoma and in Latin American populations.

Type 2 Diabetes

Tropical Diabetes, A type of diabetes found primarily in many tropical areas of the world has characteristics of both type I and type II. However, many areas show high rates of diabetes in populations that do not consume cassava, and some populations have high cassava consumption and low rates of diabetes. Risk factors for tropical diabetes involve unique dietary items. Information is relatively sparse on the genetics of diabetes in tropical countries. Recent studies have shown great population variability in increased susceptibility to diabetes. Genetic studies of Indian populations suggest a stronger familial factor among them compared to diabetics in other populations. For example, some types of cassava (manioc) may be toxic and produce pancreatic damage. In Kenya, a local alcohol called changaa is implicated in causing the disease. Finally, in most tropical areas carbohydrates constitute 70–80 percent of total calories, and such a diet is implicated in classic malnutrition diabetes because of low nutrient density and high fiber content.

In general, cities in the United States report a higher prevalence of gestational diabetes than do European cities. This form of the disease is difficult to distinguish from type II diabetes because a woman could have diabetes before pregnancy but not have it diagnosed until pregnancy. A type of diabetes present only during pregnancy was noted in 1882, which was Gestational diabetes. Babies born to diabetic mothers usually are large but may have immature organ systems, in which case they may not survive. However, it was not until the 1940s that the term “gestational diabetes” appeared in medical literature. The highest reported rate of gestational diabetes occurs among the Pima Indians of Arizona, who also have the highest prevalence of type II diabetes of any known population.

The publish paper from the University of Cambridge gives a historical side to diabetes. It does not go into any form of detail information on the chemistry of the disease but the implications. My reasoning for choosing this paper is due to the hormone Insulin. Insulin is a chemical messenger which contains several Amino Acids, 51 to be exact, which codes for its structure and function in the process. The document gives a brief over view of Diabetes but not the Biochemistry of it.

-Carlos

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April 13, 2013 | Categories: Uncategorized | Tags: Amino Acids and Proteins, BIOL 1362, Diabetes, Insulin | 1 Comment