Diabetes - The Killer Disease

Ninan Sajeeth Philip¹

Glucose is a simple sugar that is the prime source of energy for the body tissues. The digestive process turns the carbohydrates into glucose which is distributed throughout the body via the bloodstream. The brain requires a constant supply of glucose. In addition, body cells also need glucose for immediate energy. However, these only account for a portion of the glucose intake. The rest is stored in the liver and muscles as a starch called ``glycogen", or in adipose tissue as ``fat" to be used later. The glycogen will be turned back into glucose as and when the body requires extra energy.

The normal body maintains an even balance of glucose in the blood (blood sugar) taking care of all its energy needs. Any disruption in this delicate balance creates a chemical imbalance: HYPOGLYCEMIA - too low blood sugar level; or HYPERGLYCEMIA - too high blood sugar level. Insulin, the hormone secreted by the Pancreas, is what maintains the proper levels of blood sugar. When the pancreas does not produce enough insulin to retain this balance, blood sugar increases and causes diabetes.

Diabetes is broadly classified into two.

1. Insulin-Dependent Diabetes Mellitus (IDDM): This is the Type 1 diabetes often found in children. In this case, the $\beta$-cells in the pancreas produces no insulin and daily insulin injections are necessary for the diabetic's very survival.
2. Non-Insulin-Dependent Diabetes Mellitus (NIDDM): This is the type 2 diabetes that mostly affects the elderly. In this case, the $\beta$-cells in the pancreas does produce insulin (to varying degrees), but the body tissues are not able to use it properly to control blood glucose levels.

About 95% of all reported diabetics cases belongs to Type 2 diabetes, commonly known as the ``Non-Insulin-Dependent Diabetes Mellitus" or NIDDM and is found mostly among middle-aged or later. Obesity and sedentary lifestyles are found to be closely associated with type 2 diabetics. Although type 2 diabetes was initially thought to affect only the elderly, an alarming increase in the occurrence of type 2 diabetes at younger age is also causing lot of concern. In 1998, Pinhas-Hamiel et al. reported a study[6] in that they retrospectively examined the medical records of 1027 adolescents with diabetes and found that in 1992 only 2%-4% of subjects had type 2 diabetes and that it rose to 16% in 1994. It is also observed that diabetics has a genetic affinity having more likelihood to affect specific genetic groups of people. For example, studies conducted in the USA reveal that the ethnic Americans are more prone to diabetics as compared to Caucasians and that African Americans are about twice as much susceptible to diabetics related blindness.

Type 2 diabetes can go unnoticed for long periods and can result in microvascular complications by the time of detection. Studies indicate[5] that about 21% of the diabetes patients have retinopathy at the time of initial diagnosis, substantiating the urgency in developing preventive medication and early detection methods.

Research in diabetes mostly aim the development of medicines that can serve the following objectives.

1. Medicines that can reduce the insulin resistance of the body, a major cause believed to result in the failure of the $\beta$-cells².

2. Medicines that can catalyse the efficiency of the surviving impaired $\beta$-cells of a diagnosed diabetes patient who cannot otherwise survive without insulin injections.