[PHP Nepal Vol 2 Issue 10 Oct Nov 2012] | Diabetes is a multi-factorial disease showing a rising trend in all over the world. Global prevalence of diabetes: estimations for the year 2000 and projections for 2030 in 2004, estimated that the number of adults affected by diabetes in the world will grow from 175 million in 2000 to 366 million by the year 2030. Currently, China and U.S. are the countries which harbor the largest number of people with diabetes, in the age range of 45- 65 years with more number of women being affected than men. Nepal Diabetes Association revealed that, around 15%of the people above or equal to 20 years and 19% of the people above or equal to 40 years in urban areas have diabetes in 2007 in Nepal.
Similarly, according to the World Health Organization (WHO) report, the blood glucose level in Nepal in both the sexes was 8.4mmol/L among adults aged more than 25 years in the year 2010.
Diabetes is a metabolic disorder characterized by hyperglycemia, glycosuria, often accompanied with negative nitrogen balance and sometimes ketonemia. Unless carefully monitored and controlled, it can lead to complications like retinopathy, neuropathy and peripheral vascular insufficiencies. Diabetes mellitus (DM) has been classified in two forms – Type 1 and Type 2 DM. Type 1 diabetes mellitus also known as insulin-dependent diabetes mellitus (IDDM) accounts for about 10% of all the cases of diabetes in worldwide and is caused by autoimmune destruction of pancreatic β-cells producing insulin deficiency. It is also referred to as juvenile- onset diabetes because it typically present in childhood or puberty. Type 2 DM known as non-insulin dependent diabetes mellitus (NIDDM) results from the combination of insulin resistance and /or β-cell secretary defect. It comprises over 90% of clinical cases in world wide. Type 2 DM until recently has rarely affected people before middle age. The main clinical features of type 1 and type 2 diabetes are polyuria, polydipsia, accompanied by weight loss, tiredness and ketoacidosis. Ketoacidosis is normally absent in type 2 diabetes but it may develop in uncontrolled cases
The various risk factors associated with DM are obesity, genetic disposition, impaired insulin secretion and insulin resistance, hyperglycemia, unhealthy diet, alcohol, smoking and lack of physical exercise among others. Obesity elevates serum fatty acid concentration and fatty acids especially polyunsaturated fatty acids which are preferential targets of peroxidation by reactive oxygen species (ROS). The enhanced lipid peroxidation may cause insulin resistance by inhibiting the enzymes. In addition to these activities, ROS may also enhance some gene activity which potentially induces beta-cell apoptosis. Malfunctioning of genes may result in destruction of pancreatic beta-cells or insufficient production of insulin or insulin resistance. The net result is hyperglycemia and due course of time dyslipidemia. Several complications in DM type 2 are due to chronic hyperglycemia intercalated by ROS and oxidative stress (OS). The hyperglycemia induces OS through several metabolic pathways such as glucose autoxidation, polyol pathway, and exaggerated formation of advanced glycated end products.
Diet has putative influence on DM and its associated complications. High fat diet and high calorie diets, leading sedentary life without any physical exercise become overweight thus reduces the sensitivity of the tissues to the action of the insulin in the utilization of glucose.
Ironically, one gram of tar phase of tobacco contains 1017 species of ROS and one puff of gas phase of smoke contains as many as 1015 species of ROS. Alcohol itself partly gets converted into free radical. It’s metabolism in liver facilitates ROS production by altering the levels of some metals and reduces the levels of antioxidants.
Stress has long been suspected as having major effects on metabolic activity. The effects of stress on glucose metabolism are mediated by a variety of “counter-regulatory” hormones that are released in response to stress and that result in elevated blood glucose levels and decreased insulin action. Thus, stress is potential contributor to chronic hyperglycemia in diabetes.
The risk of diabetes can be reduced by taking healthy diets, avoiding smoking and alcoholic drinks, more intakes of fruits and vegetables regular physical activity and regular glucose and glycosylated hemoglobin (HbA1c) estimation. HbA1c provides a measure of the average blood glucose concentration over the 6-8 weeks. This is useful for patients with diabetes, to show how well their glucose concentration is being controlled over a period of time.
Takkella Nagamma is a Senior Grade Lecturer in Department of Biochemistry at Melaka Manipal Medical College (Manipal Campus), Manipal, Karnataka, India.