Mr CHAN, an 80 year old man with diabetes, went to a pharmacy to refill his diabetes medications. He had been seeing the same general practitioner for 20 years and taking the same regimen for 20 years:

Metformin 1000mg twice a day

Glibenclamide 5 mg once a day

a) What type of diabetes is he likely to have? (1 mark)

The patient is elderly and not on insulin, this indicates he has Type 2 diabetes mellitus which is what 90% of DM patients have.

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Insulin is a hormone secreted by the beta cells of the pancreas. It is secreted into the blood circulation in response to food.

Insulin receptors activate the glucose channels in the body's cells, enabling glucose to enter and provide them with energy. All cells require energy, muscle and brain cells in particular require large amounts of glucose to function effectively.

Type 1 diabetes is an auto-immune disease where the beta cells have been destroyed and the pancreas is unable to secrete any insulin at all. This requires total insulin replacement treatment. T1DM typically occurs in younger patients.

Type 2 diabetes is a disease of ageing, where there is gradual and progressive degeneration of the beta cells.

• In many patients there is also a second mechanism which is reduced insulin receptor sensitivity. This is known as insulin resistance and is often hormone or diet related.
• T2DM is treated with diet, exercise, and medication.
• In advanced T2DM insulin may also be required.

A lot of insulin medication work by either:

• Increasing insulin levels or
• Reducing insulin resistance

Gentle exercise is an effective way to temporarily reduce insulin resistance which is why walking after eating is encouraged.

Gestational diabetes occurs because pregnancy hormones increase insulin resistance. The risk of occurrence is higher in older mothers.