The huge rise in the type-2 diabetes population - and the introduction of major new drug treatments - is set to pose some increasingly tough management decisions, writes Jenny Bryan

When the National Institute for Clinical Excellence gave its blessing to the new type-2 diabetes treatment, rosiglitazone (Avandia) in August it effectively committed health authorities in England and Wales to add up to£14.5m to the annual diabetic drug budget for the two countries.

1Based on data from manufacturers SmithKline Beecham that 72,800 patients could be suitable for rosiglitazone treatment, the extra cost reflects the difference in price of using it instead of insulin - the traditional add-on therapy for type-2 diabetes patients who have failed to respond to or are unable to take oral treatments.

Set against the£2bn which the NHS is estimated to spend on total diabetes care, adding£14.5m may not raise any purchasers' blood pressure. But the picture looks quite different in the context of the modest£60m currently spent on oral anti-diabetic drugs.

Quite simply, the drugs which doctors have used to treat type-2 diabetes for the last 20 years are remarkably cheap, but the new generation of products - of which rosiglitazone is only one - will reflect current drug prices.

Compared with the£10,000 it costs to treat a multiple sclerosis patient with beta interferon, the£430 price tag on a year's treatment with rosiglitazone looks a bargain. But compared with the£25-30 per year for the older sulphonylureas and metformin which form the mainstay of type-2 diabetes treatment, it's not cheap. And this is only the start of a radical change in the way the disease is likely to be managed in the future. Diabetes is affecting a rapidly escalating number of people, of whom about a million are thought to be undiagnosed.

Professor David Leslie, from St Bartholomew's Hospital, London, predicts major funding problems: 'Diabetes management and care has been extremely cheap and has involved drugs that have been around for many years.

'But we now have an epidemic of diabetes and it's going to get worse.

As treatment gets more expensive and we have more patients with diabetes, there will be major funding problems.'

He and other diabetes specialists are frustrated at the difficulties they are experiencing in getting new diabetes drugs on to hospital formularies. When new agents are added, they are often expected to replace older products rather than increase the range of treatments available to prescribers.

'You don't see that happening in blood-pressure treatment. Many hypertensive patients need four or five different drugs, so why not diabetic patients?' says Professor Leslie. 'Most of the new diabetes drugs coming on to the market will be used in combination with drugs we already have, not instead of them.'

Costs could escalate still further if pressure to introduce diabetes screening is reflected in recommendations contained in the national service framework on diabetes, due out next year.

Recently released data from the UK diabetes information analysis and benchmarking service showed that at least a third of nearly 92,000 patients with type2 diabetes identified in the review had complications before being diagnosed, suggesting the need to find and treat them earlier.

Overall, complications started at least a decade before diagnosis but kidney problems started even earlier, nearly 19 years before diagnosis, while eye damage started later, nearly eight years before diagnosis.

Malcolm Roxburgh, research officer at Diabetes UK, where the analysis was carried out, explains that the new data is more detailed than previous studies and demonstrates the potential to use such registries for assessing the cost benefits of screening highrisk populations.

'There isn't a consensus yet on how screening could be done, and we need to work out the most cost-effective method, ' he says. 'The data from our study confirmed that age, social deprivation and ethnicity all affected the onset of complications and this may help identify highrisk practices where screening could be most worthwhile.'

Professor Leslie explains that the 0.5 per cent to 1 per cent improvements in the commonly used index of glucose control (HbA1c) seen with the new antidiabetic agents are well worth having since they equate to an approximately 25 per cent reduction in diabetic complications. Earlier diagnosis and treatment of diabetes should therefore help reduce the cost of treating complications of the disease in the short term. But is it merely adding to the long-term financial consequences of the disease?

'By investing money in their treatment, we will be keeping these patients alive and not having to pay out to treat their eye and kidney disease, ' says Professor Leslie.

'But, 20-30 years later, when we would previously have expected these patients to have died as a result of their complications, they will still be alive and requiring optimal diabetic therapy, and this is going to be very expensive.'

Nor are the latest anti-diabetic agents the only drugs they are likely to be taking. In 1998, the UK prospective diabetes study showed that, if anything, tight blood-pressure control is more effective in reducing diabetic mortality and morbidity than good glucose control.

And evidence is accumulating that patients with diabetes are big beneficiaries of statin treatment, too.

4If the large intervention trials in progress show that statins can bring down the risk of heart attacks and strokes in type2 diabetes patients to that of nondiabetic patients, it will be hard for GPs to resist the pressure to prescribe.

REFERENCES

1 National Institute for Clinical Excellence. Guidance on Rosiglitazone in Type-2 Diabetes. Available at www.nice.org.uk

2 UK Prospective Diabetes Study (UKPDS) Group. Intensive BloodGlucose Control with Sulphonylureas or Insulin Compared With Conventional Treatment and Risk of Complications in Patients with Type2 Diabetes (UKPDS 33). Lancet 1998; 352: 837-853.

3 UKPDS. Tight Blood Pressure Control and Risk of Microvascular Complications in Type-2 Diabetes: UKPDS 38. BMJ 1998; 317: 703-713.

4 Pyorala K, Pedersen TR, Kjekshus J et al. Cholesterol lowering with simvastatin improves prognosis of diabetic patients with coronary heart disease. A sub-group analysis of the Scandinavian Simvastatin Survival Study (4S). Diabetes Care 1997; 20: 614-620.

5 UKPDS Group. UK Prospective Study 16: Overview of six years' therapy of type-2 diabetes - a progressive disease. Diabetes 1995; 44: 1249-1258.