The pathogenesis and pathophysiology of type 1 and type 2 diabetes mellitus

Abstract

The aim of this paper is to review the information on type 1 and type 2 diabetes with emphasis on its etiology, pathogenesis and pathophysiology via literature review. Diabetes is a group of metabolic disorders characterized by a chronic hyperglycemic condition resulting from defects in insulin secretion, insulin action or both. Type 1 diabetes is the result of an autoimmune reaction to proteins of the islets cells of the pancreas while type 2 diabetes is caused by a combination of genetic factors related to impaired insulin secretion, insulin resistance and environmental factors such as obesity, overeating, lack of exercise and stress, as well as aging. The pathogenesis of selective β-cell destruction within the islet in type 1 diabetes mellitus is difficult to follow due to marked heterogeneity of the pancreatic lesions. At the onset of overt hyperglycemia, a mixture of pseudoatrophic islets with cells producing glycogen, somatostatin and pancreatic polypeptide, normal islets and islets containing both β-cells and infiltrating lymphocytes and monocytes may be seen. The autoimmune destruction of pancreatic β cells leads to a deficiency of insulin secretion that leads to the metabolic derangements associated with type 1 diabetes. The main pathophysiological features of type 2 diabetes are impaired insulin secretion and increased insulin resistance. The impairment of pancreatic β cell function notably shows progression overtime in type 2 diabetes although aging, obesity, insufficient energy consumption, alcohol drinking, smoking, etc are independent risk factors of pathogenesis of type 2 diabetes mellitus.

Management of type 1 and type 2 diabetes requiring insulin

“…7 A myriad of risk factors for T2DM have been identified (see Table 3). 8 Factors such as ethnicity play a significant role in determining those at high risk of T2DM with its prevalence increasing four-fold in people of Bangladeshi and Indian origin, and five-fold in women of Pakistani origin.…”

Antidiabetic effects of Cycas edentata aqueous leaf extract on the blood glucose levels of alloxan-induced diabetic imprinting control regions mice (Mus musculus L.)

“…Insulin-dependent diabetes mellitus (type I) is an autoimmune disease, wherein there is an insufficient supply of insulin caused by destruction of pancreatic beta-cells in the islets of Langerhans. [2,3] On the other hand, non-insulin diabetes mellitus (type II) resulted from the lack of insulin secretion by beta-cells of the pancreas and greater insulin resistance. [3] The latter represents about 90% of diabetic population, which suffers from complications that include negative effects on the eye, kidney, and nervous system.…”

“…[2,3] On the other hand, non-insulin diabetes mellitus (type II) resulted from the lack of insulin secretion by beta-cells of the pancreas and greater insulin resistance. [3] The latter represents about 90% of diabetic population, which suffers from complications that include negative effects on the eye, kidney, and nervous system. [4] Treatment of diabetes mellitus is geared toward management and control of hyperglycemia.…”

Ethanol Extract of Tithonia diversifolia (Hemsley) A Gray Standardized Ameliorates Hyperglycemia, Polyphagia, and Weight Loss in Diabetic Rats

“…Diabetes mellitus is characterized by chronic hyperglycemia due to insufficient insulin production, insulin action failure, or both (American Diabetes Association, 2008;Ozougwu, Obimba, Belonwu, & Unakalamba, 2013). Insulin plays a role in moving glucose into cells to be converted into energy.…”