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| What is Diabetes : Diabetes Symptoms : Diabetes Treatment : Diabetes Care : Diabetes Diet : Hypoglycaemia : Complications : Gestational Diabetes Test |
Type 2 DiabetesMore than 80 per cent of people with diabetes in Britain have this form (formerly Non-Insulin Dependent Diabetes Mellitus or NIDDM), as do the estimated 'missing million' who are currently undiagnosed. Type 2 diabetes is regarded as being a heterogeneous disorder, that is, one in which there may be two contributing defects and other associated adverse factors. One defect or adverse factor may have a relatively greater impact upon one person with the syndrome compared to another and this underlines the need for an individual approach when it comes to treatment. In contrast to Type 1 diabetes, in Type 2 disease people have a relative, rather than an absolute, loss of insulin. However, the disorder is a progressive one and in many cases the situation, both with regard to insulin secretion and the effectiveness of its action, may worsen with time. Type 2 diabetes has a long, 'silent', asymptomatic period lasting many years, and usually people are not diagnosed until they are over the age of 40 (but see below). During this time, enough insulin is produced or is effective to prevent keto-sis but not enough to ensure a normal disposal of glucose. Hence there is sustained hyperglycaemia and very often the development of resultant tissue damage and diabetic complications. There are two sub-groups of Type 2 diabetes which, while they overlap with one another, tend to have somewhat different underlying causes - the two contributory defects mentioned above. People in the first sub-group, who are in the minority, are usually thin or of normal body weight. Those in this group are more likely to have a deficiency in the secretion of insulin as the underlying cause of their diabetes. In the second sub-group, comprising over 75 per cent of cases, people are likely to be overweight or obese. In those affected, insulin resistance is likely to be the predominant malfunction. Insulin resistance is a common feature of Type 2 diabetes and it is known that it mainly occurs at post-receptor level, affecting metabolic events that take place within cells. However, it should be stressed that these distinctions are not necessarily clear cut and both insulin deficiency and insulin resistance can be at work in either sub-group of Type 2 diabetes. However, there is universal agreement among medical experts that the rising tide of obesity among people in Western countries is closely linked with an escalating incidence of Type 2 diabetes that is reaching epidemic proportions. Of particular concern is the fact that Type 2 syndrome has recently been identified in obese teenagers, both in the USA and in Britain. It is feared that since many more children are now significantly overweight or obese than was the case a generation ago, cases of early Type 2 diabetes will become more common. Indeed, one study in Plymouth showed that 26 per cent of 5-year-old girls surveyed were not only overweight but were exhibiting early signs of resistance to insulin. People least likely to be affected are those living in countries where a traditional lifestyle and diet are followed. At greatest risk are those who have rapidly changed from eating a traditional diet to a Western one and some racial groups also appear to be particularly vulnerable (e.g. South Asians living in Britain). There is a strong genetic/inheritance link in the development of Type 2 diabetes but less is known about the genes involved. The familial pattern is as follows:
Information about diffrent diabetes types. |