SOME QUESTIONS AND ANSWERS

What are the signs of diabetes?

In both type 1 and type 2 diabetes, the signs of the disease may include:

• thirst (with frequent drinking)
• frequent urination
• unexplained weight loss
• fatigue and weakness
• blurred vision
• numbness or tingling in the hands and feet.

While these may be considered the classic symptoms of diabetes, not all may be present, especially in type 2 diabetes, in which symptoms may be slight at first.

In addition, raised blood sugar (hyperglycaemia) may result in glucose appearing in the urine. If this has been present for some time, this may lead to itching or a rash in the urogenital area, due to infection by yeasts.

Other symptoms may develop in type 1 diabetes, including muscle cramps and gastrointestinal symptoms, such as nausea and vomiting, abdominal pain and changes in bowel movements. The disturbances in glucose metabolism may be so severe that a state termed diabetic ketoacidosis (DKA) develops, with severe dehydration, rapid shallow breathing, a fruity breath odour, and impairment of consciousness. DKA is a medical emergency and requires immediate treatment in hospital to avoid a possible fatal outcome.

In type 2 diabetes, if initial symptoms are mild or absent, tissue damage due to complications of the disease may already have developed by the time of diagnosis. This includes damage to the:

• nerves (neuropathy)
• kidneys (nephropathy)
• eyes (retinopathy - which can result inblindness)
• cardiovascular system - which can lead to a heart attack or stroke.

Gestational diabetes is usually found through screening before symptoms develop. High blood pressure may develop, possibly in a more severe form (pre-eclampsia).

What precedes diabetes?

In both type 1 and especially type 2 diabetes, the processes causing loss of blood glucose regulation typically begin long before the condition is diagnosed. Often, symptoms which lead the individual to see a doctor, and hence to a diagnosis, only emerge when most pancreatic beta-cell function has already been lost and/or when insulin resistance is already significant. During this silent phase, however, some biochemical changes, particularly abnormal blood glucose levels, can be detected and may be discovered by chance. This situation may be referred to as “pre-diabetes”, although this term is not universally accepted in clinical use in Britain.

Fasting blood glucose levels (the minimum level of blood glucose reached a long time after eating, as after an overnight fast) above 6.1 mmol/L, but below 7.0 mmol/L are regarded as abnormal, but not elevated enough to indicate diabetes, according to criteria established by the World Health Organisation.

Impaired glucose tolerance (IGT), indicated by an insufficient response to ingested glucose in a standardised test is the other indicator of abnormal glucose regulation that may not be severe enough to satisfy the criteria for a diagnosis of diabetes. In some cases, both of these abnormalities may be seen in the same individual.

“Pre-diabetes” is an intermediate stage in the progression from normal glucose regulation to diabetes requiring insulin treatment. Not all people go on to develop full diabetes (in one large study, about 6 per cent of those with IGT given diet and exercise information but not otherwise receiving intensive treatment went on to develop diabetes per year) and some may even return to a normal blood glucose level over time. Abnormal glucose regulation is, however, a significant risk factor for diabetes, and should be addressed by patient and healthcare team together.

Some people with insulin resistance or diabetes may also have two or more of:

• Central (apple-shaped) obesity
• High blood pressure (hypertension)
• Dyslipidaemia (abnormal blood lipid pattern)
• Micro-albuminuria (presence of protein in the urine),

and this cluster of factors is referred to as “metabolic syndrome”, as defined by the WHO. People matching this definition are at a much increased risk of developing cardiovascular disease (heart attack or stroke).