Improved understanding of how diabetes develops has significantly expanded the range of therapies available, but has also made decisions about treatment far more complex.
In other conditions, the number of classes of drugs has risen steadily over the past 60 years, but diabetes care has seen huge changes in the past decade alone. The number of different BP drugs, for example, has increased steadily since the 1950s and there are now 11 classes of hypertension drug.
In diabetes, there were until 2002 only four main therapies available – insulin, metformin, sulfonylureas and glucosidase inhibitors. Next year, there will be at least a dozen.
Professor David Matthews of Oxford University's diabetes, endocrinology and metabolism centre believes clinicians now face a situation where 'the alternatives are too complex'.
This complexity is only going to increase as more therapies become available.
Warwickshire GP Professor Roger Gadsby, associate clinical professor at Warwick Medical School, says a 'vast number' of new diabetes therapies are now being developed.
Data were presented at the European Association for the Study of Diabetes (EASD) meeting in Berlin, Germany, this month on two new gliptins (DPP-4 inhibitors), two new glucagon-like peptide-1 (GLP-1) receptor agonists and seven compounds in a whole new class of drugs – inhibitors of the sodium-glucose linked transporter-2 (SGLT2) protein.
Professor Gadsby believes the SGLT2s mark a step forward in terms of treatment available in an oral form. 'The SGLT2s lower glucose and weight, and we have not been able to do that in a tablet before,' he says.
Quadruple therapy
Isle of Wight GP Dr Eugene Hughes, who has a special interest in diabetes, says data presented at the EASD meeting suggested that SGLT2s could be used as part of quadruple therapy. 'These agents could be added to triple therapy, before moving on to injectables,' he says.
Data were also presented on new insulins in development and weekly DPP-4 inhibitors. Newer insulins could reduce night-time hypoglycaemia, and researchers are also studying the potential of oral insulin formulations.
Professor Matthews is adamant that the expanding range of treatments is good news for patients, because it gives clinicians greater choices when tailoring patients' therapy.
'The choice is a really good thing,' he told the EASD meeting. 'We have to thank the pharmaceutical industry for taking this extremely seriously.'
Dr Hughes says that even without new treatments, much more could be done to improve diabetes care. 'We have at our disposal a range of effective therapies which, if used properly and judiciously, and if people would step up therapy, would help achieve maximum benefit,' he says.
Professor Gadsby believes GPs are already beginning to 'turn the tide' in terms of the outcomes for patients with diabetes, even before these new therapies are launched.
'It's been clear for the past 10 years that you need multifactorial interventions in diabetes to lower the microvascular and macrovascular risk, and we're beginning to see the benefits of that approach,' he says.
He says the rise in prevalence of the disease makes it difficult to appreciate any emerging evidence of reductions in complication rates for individuals.
Surrey GP Dr Neil Munro, an associate specialist in diabetes at the Chelsea and Westminster Hospital, London, says there is unlikely to be a 'perfect treatment' for diabetes.
He points out that even if clinicians did everything possible with current therapies, patients with diabetes would face raised complication risks. 'We are still a long way from understanding how diabetes develops and ways of managing it,' he says. 'There is a pressing need for a massive amount of research.'
Improved care
Dr Munro says there has been an 'enormous amount' of improvement in care over the past 30 years.
But he believes clinicians will need a greater understanding of the processes underlying diabetes if they are to help the huge number of people affected.
'The rate of expansion of it is far beyond any other diseases,' he says, pointing to projections suggesting that 4.4m in the UK will have diabetes by 2020.
'Diabetes will remain a challenge for researchers,' he says. 'But without new research, clinicians will struggle to improve services.'
