Health News, Information and Advice from a British Doctor

Type 2 diabetes

Type 2 diabetes accounts for 90% of all diabetes, the other 10% comprising mostly type 1 diabetes and a very small percentage gestational diabetes (diabetes of pregnancy). It is a metabolic condition that causes high levels of sugar in the blood with osmotic symptoms of thirst, excess urine production and also hunger.

Unlike type 1 diabetes where there is an absolute lack of insulin production by islet cells in the pancreas, circulating insulin levels in type 2 diabetes may be low, normal or even high and there appears to be a resistance by cells in the body to the action of insulin, to stimulate glucose uptake. Glucose is an important source of energy for normal cellular function.

In western society it is almost exclusively associated with obesity, although in the far east this association is not so strong.

Long term complications of diabetes include heart disease, stroke, peripheral vascular disease, retinopathy (with associated visual impairment), increased risk of infections and kidney damage.

Unlike type 1 diabetes where insulin replacement is vital, type 2 diabetes is initially managed by weight reduction, exercise and healthy eating. Oral hypoglycaemic agents such as metformin and gliclazide may also be required and on occasions even insulin, if satisfactory glycaemic control has not been established.

There are a whole tranche of newer oral hypoglcaemic agents but they are usually prescribed by hospital specialists and their efficacy over the standard oral hypoglycaemic agents is still being evaluated.

In patients with extreme obesity, weight reduction surgery can be an effective way of treating type 2 diabetes.

Type 2 diabetes is diagnosed by measuring blood sugar levels. A fasting blood sugar of over 7 mmol/l or a non-fasting level of over 11.1mmol/l is diagnostic. Your GP may ask you to have a glucose tolerance test where you are given a glucose load and then your blood levels are measured 2 hours later. A level of over 11.1mmol/l is diagnostic.

Glucose control once diagnosed, is usually assessed by measuring your glycated haemoglobin levels (HbA1c) which gives an indication of the glucose levels over a few weeks. HbA1c is also used as a test to diagnose diabetes (>48).