Diabetes mellitus is a chronic and progressive disease, which has been described as a state of raised blood glucose associated with premature mortality. It arises when the pancreas fails to produce enough insulin (type 1 diabetes mellitus, previously called Insulin Dependant Diabetes Mellitus or IDDM) or when the body can't effectively make use of the insulin produced (type 2 diabetes mellitus, previously called NIDDM or non-insulin dependant). Type 2 diabetes is more common and accounts for 90-95% of cases.
In 2007 there was an estimated 171 million people with diabetes worldwide, this figure is expected to double over the next 25 years.
Diabetes impacts upon almost every aspect of life and can result in a variety of complications. It is one of the main causes of amputation of the lower extremities and is the biggest single cause of eye disease in working age adults. Diabetes manifests more abruptly in type 1 diabetes and classically presents as an unwell child or teenager with excessive thirst and frequent urination. Type 2 takes an average of 7-10 years to diagnose and may be detected pre-symptomatically by way of screening programmes.
Those at high risk of developing type 2 diabetes for example, those who are obese, have cardiovascular disease (CVD) risk factors or have a family history of diabetes should be screened regularly. The World Health Organisation (WHO) encourages the use of the oral glucose tolerance test for the diagnosis of type 2 diabetes when the fasting or random plasma glucose test is not conclusive. On the other hand, the American Diabetes Association (ADA) advocates the use of random and fasting plasma glucose alone. Both currently agree that HbA1c (glycated haemoglobin) and point of care testing for whole blood glucose should not be employed to diagnose diabetes.
Good glycaemic control is the key to reducing the onset and progression of secondary complications and HbA1c and fructosamine are commonly used tests for this. HbA1c has an average lifespan of 120 days and provides an index of glycaemia over the previous 2-3 months. Fructosamine (also called glycated serum protein), has an average lifespan of 15-20 days and thus reflects the glycaemic control over the previous 1-2 weeks. Thus, fructosamine can be utilised when assessing short-term changes in glycaemic status, for example, in diabetic pregnancy or after major changes in therapy.
Diabetes is closely associated with CVD and therefore an increased risk of heart attack, stroke and amputation of the lower limbs. Indeed, heart attack and stroke are the major causes of premature death in people with diabetes. Accordingly, CVD risk assessment and treatment is important in patients with diabetes.
Diabetes has also been associated with kidney, eye and nerve disease. Approximately 8% of healthcare budgets in developed countries are spent on diabetes with the vast majority of this allocated to treating the associated long-term complications. Accordingly, more emphasis is now placed on preventing these complications by regularly testing for risk factors and aggressively treating the conditions when they are present. For example, the expert consensus opinion of the ADA is the performance of an annual test for the presence of microalbuminuria in all type 1 diabetic patients who have had diabetes for more than 5 years and all type 2 diabetic patients starting at diagnosis.
It is recommended that diabetics have regular assessments covering the following parameters:
In diabetic ketoacidosis (DKA), there is accumulating evidence that regular blood ß-Hydroxy Butyrate levels safely allow for earlier discharge of patients than urinary levels.