15 Dec 2010

Diabetes and insulin: your questions answered

Following a joint Channel 4 News and British Medical Journal investigation on diabetes drugs Tom Clarke explains what the illness is and what you should do if you’re affected.

What is diabetes?

Diabetes is a condition where the body can’t make insulin, makes too little, or becomes resistant to the effects of insulin. There are two main types. People with Type 1 diabetes lose the ability to make insulin – usually in childhood. This form of the disease would be fatal unless treated with insulin injections. Type 2 diabetes occurs later in life and is linked to being overweight, a poor diet, smoking and a lack of exercise.

Type 2 diabetes can be managed by controlling diet and with drugs to moderate blood sugar. However some people with Type 2 diabetes end up requiring insulin injections to manage their disease. In the UK between 5 per cent and 15 per cent of people with diabetes have Type 1. Between 85 per cent and 95 per cent of people have Type 2. In total there are 2.8 million people with diabetes in the UK. An additional 850,000 are thought to have the condition but don’t know it.

What is insulin?

The view of diabetes specialists is to stick to the insulin you and your body are used to

Insulin is a hormone produced by our pancreas which tells the body to absorb sugar from our bloodstream. Because people with diabetes either don’t produce, or don’t respond as well to insulin, those with more advanced forms of the disease need to inject insulin to keep their blood sugar at a safe level. There are many different types of insulin formulation. All insulin users take a long-acting form which keeps their blood sugar in check. Many others also use short-acting insulins to reduce spikes in blood sugar level around mealtimes. Some insulin products are a mixture of long and short-acting insulins. Some people with diabetes are given a computer-controlled insulin pump which delivers insulin under the skin. This does away with regular insulin injections.

Why is diabetes such a massive burden on the NHS?

Diabetes is an incurable, chronic disease. That means once someone begins treatment they require it for the rest of their life. The costs of diabetes medicines, including insulin, are part of the cost. So are devices that allow people to test their blood sugar levels several times a day. But the main cost burden of diabetes results from the complications brought about by having too high, or too low levels of sugar in the blood. Poorly managed diabetes can lead to increased risk of heart disease and stroke, blindness, kidney failure and amputations due to poor circulation.

Channel 4 News reports on diabetes investigation:

NHS wastes tens of millions on expensive diabetes drugs
A joint investigation by Channel 4 News and the BMJ reveals the NHS spends tens of millions more than necessary on modern insulins to treat diabetes despite guidance from NICE to use cheaper products.

Diabetes and insulin: your questions answered
Tom Clarke explains what the illness is and what you should do if you're affected.

Why diabetes is big business for drug companies
The numbers of those diagnosed with diabetes will continue to rise but, as Deborah Cohen, Investigations Editor of the BMJ explains, the cost to the NHS does not need to spiral out of control.

Why is the diabetes burden growing?

Because the most common – Type 2 – form of diabetes is directly linked to obesity, rates of the disease are rising in-line with expanding waist-lines. Rates of Type 1 diabetes are also increasing; however scientists still don’t know what factors might be behind this rise. In all, it’s expected that there will be 4 million people with diabetes in the UK by 2025.

What is the difference between human and analogue insulin?

Both human and analogue insulins are synthetic, bioengineered versions of the hormone made in our pancreas. Human insulin is grown in bacteria expressing the human genetic code for insulin. Analogue insulins are made in the same way, only the human insulin molecule is modified. Changes speed or slow the rate at which insulin becomes available to the body.

What are the advantages of analogue insulins?

Research shows that both human and analogue insulins lower blood sugar in exactly the same way. However, analogue insulins can release the hormone into the blood more quickly (short acting) or more smoothly (long acting). Many users say this makes their diabetes easier to control and can require fewer insulin injections each day. Research shows analogue insulins are better at preventing night-time hypoglycaemia. This complication, experienced by some insulin users, occurs when blood sugar levels fall too low during the night. There is also some evidence to suggest one of the long-acting analogues produces slightly less weight gain – a common side effect of insulin therapy – than other insulins.

Why the fuss about analogue insulins?

Analogue insulins have some clinical advantages over human insulins. However, they cost significantly more than the previous generation of human insulins. In the view of the National Institute for Clinical Excellence, the body which controls drug pricing in the NHS, people with Type 2 diabetes should be started on the less-expensive human insulins when they first begin insulin treatment. If this form of treatment doesn’t give adequate results they should then be moved onto the more expensive analogue insulins.

Who makes analogue insulins?

In the UK, analogue insulins are produced by Sanofi-Aventis, Novo Nordisk and Lilly UK.

Why are people switching from human to analogue insulins?

Some people are prescribed analogue insulins for important clinical reasons. Some diabetes specialists, and the companies that make analogue insulins, feel the advantages of analogue insulins mean all insulin-requiring diabetics should be given them. However, other diabetes experts worry that too many diabetics are being prescribed these more expensive forms of insulin even though they offer them no significant benefit. They argue this is wasting already tight NHS funds for treating all aspects of diabetes.

If I am on analogue insulin, should I think about switching back?

No. The view of diabetes specialists is to stick to the insulin you and your body are used to. Someone with diabetes should only change the type of insulin they use for good clinical reasons and after being prescribed a new kind by their doctor. Although some insulin users may have been able to manage their diabetes well using cheaper, human insulin, once they are accustomed to a new type of insulin they should stick to it, unless they start to experience problems.