In this article, following topics are discussed: (1) Basics of Types 2 Diabetes; (2) What causes type 2 diabetes; and (3) Levels of glucose in normal and diabetic persons. Basics of Type 2 Diabetes Every cell in the human body needs energy for its survival. This energy is transferred to these cells in the form of glucose (sugar) circulating in the blood. Glucose circulating in the blood is derived from the food digested.
How is glucose converted into energy? Well, pancreas is an organ that lies in the upper abdomen behind the stomach in a human body. Pancreas produces a hormone called insulin. It is insulin that allows body cells to convert glucose circulating in blood into energy. Insulin bonds to a receptor site on the outside of cells and performs the function of a key to open a gate into the cell through which glucose can enter inside the cell.
Thus, it is necessary for the proper functioning of a human being that sufficient amount of insulin should be produced which can allow conversion of glucose into energy that can be used by the cells. Moreover, in a healthy person, insulin helps to regulate the glucose levels in blood. In a normal human being, when he eats the food, glucose is derived from the food which enters the bloodstream, thereby raising the level of glucose in blood. The cells in the pancreas which produce insulin, sense this increase of glucose level in blood, and then they produce an appropriate amount of insulin to direct such glucose into the cell for converting them into energy.
Thus, the level of glucose in blood again comes back to normal while the cells get the energy required by them. However, in a person suffering from type 2 diabetes, the human body is not able to use insulin properly. So, while the body may produce normal levels of insulin, due to some reasons the body is not able to make proper and effective utilization of insulin so produced. This is known as insulin resistance. What exactly happens is something like this. Since the body is not able to properly utilize insulin produced, at first, the pancreas makes extra insulin so as to compensate for its improper utilization; however, over a period of time, pancreas cannot keep the momentum and is not able to make enough insulin to keep level of glucose in blood at normal levels.
Thus, for a person with type 2 diabetes, glucose in the blood is not driven to the cells in view of improper utilization of insulin or lack of sufficient amount of insulin. Due to this, level of glucose rises in blood; and at the same time, cells in the body may not get sufficient energy required by them. Thus, in a person with type 2 diabetes, glucose level in blood is higher than the normal levels.
What causes Type 2 Diabetes? Type 2 diabetes is caused by various factors, usually a combination of lifestyle and genetic factors and certain medical conditions. All of these factors are not under the personal control of the individual concerned. While one can control factors such as diet and obesity that may cause diabetes, other factors such as increasing age, female gender, and genetics are beyond one’s control.
Lifestyle factors: Lifestyle factors such as obesity, overweight, lack of physical activity or sedentary lifestyle, poor diet, stress, and urbanization, etc., are known to be responsible for development of type 2 diabetes. Moreover, consumption of excessive quantities of sugar-sweetened drinks, presence of saturated fats and trans fatty acids in the food, eating excessive quantities of white rice also increase the risk of type 2 diabetes.
Genetic factors: Many genes (appx. 36 identified so far) have been identified to be contributing towards the development of type 2 diabetes. Most of these genes are involved in beta cell functions.
Medical conditions: Several medications (such as glucocorticoids, thiazides, beta blockers, atypical antipsychotics and statins) and other health problems (such as acromegaly, Cushing’s syndrome, hyperthyroidism, pheochromocytoma, glucagonomas, Testosterone deficiency) have also been identified to contribute towards development of diabetes.
What levels of glucose are normal and what level indicate diabetes? Fasting Plasma Glucose Level: The fasting plasma glucose level in blood below 110 mg/dL (milligrams per decilitre) is considered to be normal and glucose level above 126 mg/dL is considered to be diabetic. A level between 110-125 mg/dL is called “impaired fasting glucose”. Post-prandial (PP) plasma glucose: In this method, glucose level is checked two hours after having a meal. Less than 140 mg/dL level of PP plasma glucose is considered normal; a glucose level of more than 200 mg/dL is considered as diabetic. And, a glucose level between 140-199 mg/dL is called “impaired glucose tolerance”. Random plasma glucose test: It is the glucose test that is done at any other time than the above. A level of 200 mg/dl or higher is usually considered to be diabetic. It may be pointed out that usually, fasting glucose levels are checked to diagnose diabetes.