People with type 2 diabetes are deficient in insulin as well as being resistant to it’s action. Recent research (UKPDS) has shown that most people with type 2 diabetes will eventually require combination therapy and/or insulin.
Many people who are not suitable for treatment with metformin or thiazolidenediones (glitazones) due to co-existing heart failure, liver disease or kidney disease insulin treatment may also be necessary.
Many people (up to 70 per cent) report and increase in well-being following the change to insulin. Data from a large scale study of people with type 2 diabetes (UKPDS) has shown that a 1% reduction in HbA1c is associated with a near 30 percent reduction in the risk of microvascular (small-vessel) complications.
In the past, insulin therapy was often seen as a last resort in the treatment of type 2 diabetes. In recent times there has been a move to change to or add-inn insulin at a much earlier stage. This is partly due to a recognition that poor control is associated with a high risk of complications, mainly ‘small-vessel disease’.
The main disadvantages of intensive treatment incorporating insulin, are weight gain and the risk of hypoglycaemia.
Many people do gain weight after starting insulin therapy. On average this tends to be around 1-4 kg. It is difficult to predict who will gain weight. This may be due in part to stimulation of appetite.
Before considering a move to insulin it is worth examining all the option with regard to combination therapy. Diet should be optimised and the benefit of exercise discussed. It is important to be aware of the possibility of weight gain and of the need to maintain weight ‘neutral’ especially if already obese.
Any type of insulin can be used in type 2 diabetes. Pre-mixed insulin as part of a twice daily regimen is commonly used. Alternatively once daily ‘basal’ or long acting insulin can be tried in combination with oral hypoglycaemic tablets. Isophane insulin or GlargineR may be used for this purpose. Your doctor or diabetes nurse specialist will discuss these issues further if you wish.
Type 2 diabetes is associated with insulin resistance. In other words insulin works less effectively. It is not uncommon for people with type 2 diabetes to need more than one hundred units of insulin each day.
Hyperinsulinaemia (high insulin levels) used to be considered dangerous. The theoretical disadvantage of hyperinsulinaemia is far outweighed by the accepted benefits of good blood sugar control.
Treatment with metformin can be continued. Especially in overweight people metformin may help prevent weight gain. Weight loss often results in lower doses of insulin being required.
Dr Nishan Wijenaike
West Suffolk Diabetes Service