Public Awareness and Human Diseases - Report Example

Public Awareness and Human Diseases Diabetes mellitus (DM) comprises a group of common metabolic disorders that share the phenotype of hyperglycemia. Several distinct types of DM exist and are caused by a complex interaction of genetics, environmental factors, and life-style choices. Depending on the etiology of the DM, factors contributing to hyperglycemia may include reduced insulin secretion, decreased glucose utilization, and increased glucose production. The metabolic dysregulation associated with DM causes secondary pathophysiologic changes in multiple organ systems that impose a tremendous burden on the individual with diabetes and on the health care system. In the United States, DM is the leading cause of end-stage renal disease (ESRD), nontraumatic lower extremity amputations, and adult blindness. With an increasing incidence worldwide, DM will be a leading cause of morbidity and mortality for the foreseeable future. DM1 is classified on the basis of the pathogenic process that leads to hyperglycemia, as opposed to earlier criteria such as age of onset or type of therapy. The two broad categories of DM are designated type 1 and type 2. Type 1A DM results from autoimmune beta cell destruction, which leads to insulin deficiency. Individuals with type 1B DM lack immunologic markers indicative of an autoimmune destructive process of the beta cells. However, they develop insulin deficiency by unknown mechanisms and are ketosis prone. Relatively few patients with type 1 DM are in the type 1B idiopathic category; many of these individuals are either African-American or Asian in heritage. Type 2 DM1 is a heterogeneous group of disorders characterized by variable degrees of insulin resistance, impaired insulin secretion, and increased glucose production. Distinct genetic and metabolic defects in insulin action and/or secretion give rise to the common phenotype of hyperglycemia in type 2 DM. Distinct pathogenic processes in type 2 DM have important potential therapeutic implications, as pharmacologic agents that target specific metabolic derangements have become available. Type 2 DM is preceded by a period of abnormal glucose homeostasis classified as impaired fasting glucose (IFG) or impaired glucose tolerance (IGT). The worldwide prevalence of DM 1 has risen dramatically over the past two decades. Likewise, prevalence rates of IFG3 are also increasing. Although the prevalence of both type 1 and type 2 DM is increasing worldwide, the prevalence of type 2 DM is expected to rise more rapidly in the future because of increasing obesity and reduced activity levels. DM increases with aging. In 2000, the prevalence of DM was estimated to be 0.19% in people 20 years old. In individuals >65 years the prevalence of DM was 20.1%. The prevalence is similar in men and women throughout most age ranges but is slightly greater in men >60 years. The prevalence of type 2 DM and its harbinger, IGT2, is highest in certain Pacific islands, intermediate in countries such as India and the United States, and relatively low in Russia and China. This variability is likely due to genetic, behavioral, and environmental factors. DM prevalence also varies among different ethnic populations within a given country. In 2000, the prevalence of DM in the United States was 13% in African Americans, 10.2% in Hispanic Americans, 15.5% in Native Americans (American Indians and Alaska natives), and 7.8% in non-Hispanic whites. The onset of type 2 DM occurs, on average, at an earlier age in ethnic groups other than non-Hispanic whites. Mortality rates in people with diabetes exceed those in the general population despite many recent improvements in care. Diabetes is one of the most common chronic diseases in the young, and is a substantial cause of morbidity as well as mortality at all ages. After the introduction of insulin in 1922 it was hoped that adverse consequences of diabetes might become a thing of the past, but mortality rates are still higher than those in the general population and, in addition, the late complications of diabetes, in particular cardiovascular disease (CVD), have been unmasked. The National Diabetes Data Group and World Health Organization have issued diagnostic criteria for DM based on the following premises: (1) the spectrum of fasting plasma glucose (FPG) and the response to an oral glucose load varies among normal individuals, and (2) DM is defined as the level of glycemia at which diabetes-specific complications occur rather than on deviations from a population-based mean. For example, the prevalence of retinopathy in Native Americans (Pima Indian population) begins to increase at a FPG > 6.4 mmol/L (116 mg/dL). Glucose tolerance is classified into three categories based on the FPG4: (1) FPG < 5.6 mmol/L (100 mg/dL) is considered normal; (2) FPG = 5.6 mmol/L (100 mg/dL) but Read More