patient information

In April 2000, the WHO revised its definition of diabetes mellitus as a metabolic disorder of multiple causes, characterized by chronic hyperglycaemia (high blood glucose) with disturbances of:



The diagnostic criteria rely on fasting blood glucose levels and also the rise in blood glucose two hours following a 75g glucose drink. It became clear with time that there were several different types of diabetes mellitus, and the latest classification is from the American Diabetes Association 2004 (Diabetes Care 2004; 27 suppl 1: s5-s10). Although this classification describes many types of diabetes mellitus, the two main forms are types 1 and 2. Worldwide, at least 85-95% of patients with diabetes have type 2 (even higher in developing countries; International Diabetes Federation 2003), and the main differences between type 1 and type 2 are listed in Table 1.

Table 1. Main differences between type 1 and type 2 diabetes mellitus

	TYPE 1 (insulin dependent)	TYPE 2 (insulin resistant)
Epidemiology	Usually younger & lean	Mostly older & overweight
Genetic	No general genetic predisposition	Genetic predisposition
Pathogenesis	Autoimmunity	No evidence of autoimmunity
Clinical	Insulin deficiency, always needs insulin	Insulin resistance AND not enough insulin (even though insulin level may be high)

Patients with any form of diabetes may require insulin treatment at some stage of their disease. Such use of insulin does not, by itself, classify the patient.

In the last few years, there has been a significant advance in our understanding of type 2 diabetes in particular, and it is no longer regarded as a condition where the blood sugar is high (hyperglycaemia), but more as a "metabolic syndrome" of:

The physician’s emphasis is therefore no longer tailored on just monitoring blood sugar levels, but should crucially address the other aspects of type 2 diabetes, with the aim of preventing or mitigating the high potential for heart disease, stroke, peripheral vascular disease and other complications of the metabolic syndrome. Blood pressure control is paramount for the reduction in these so-called "macrovascular" complications, as proven by the large UKPDS-38 trial (Brit Med J 1998; 317: 703-713). Our goal is to achieve meticulous blood pressure control, regular review and tight control of blood lipids (cholesterol, LDL, HDL, triglycerides), lifestyle changes, and all other means of cardiovascular risk management such as cessation of smoking, low-dose aspirin therapy and regular exercise.

In parallel with these measures, it is still important to control blood sugar levels. With the outcome of large multicentre trials (UKPDS-33 Lancet 1998; 352: 837-53), it is now clear that reducing blood sugar levels towards the normal range minimizes the other complications of diabetes (“microvascular”), namely eye problems (retinopathy), kidney disease (nephropathy) and nerve problems (neuropathy).

The optimal management of diabetes therefore has to be as part of a multi-disciplinary team including diabetes physicians, cardiologists, ophthalmologists, nephrologists, diabetes specialist nurses, dieticians, podiatrists. Regularly-updated guidelines and protocols for management are critical, and the use of database systems/ registries are widely recommended.