Our experience with screening for diabetes
Dr David Whitford and Dr Colin Greaves provided an excellent overview of screening for type 2 diabetes (Clinical, May 31). They pointed out: 'Type 2 diabetes does not meet all the national screening committees criteria for screening. In particular there is no evidence that screening leads to significant improvements and outcomes, there is no specific data on the Harman costs of screening, and there is no consensus on a single specific insensitive test.'
I would suggest that diabetes is a special case, and in any event is screening for diabetes really the issue given that abnormal glycaemic states are risk factors for cardiovascular disease?
Impaired glucose tolerance is a risk factor for macrovascular disease and impaired fasting glucose is a risk factor for microvascular disease but also macrovascular disease. Where the conditions co-exist the risk is greater and the likelihood of progression to frank diabetes is additive. The exact diagnosis of diabetes is difficult and in a sense bad value for money.
Would we not be better to think in terms of screening our patients for cardiovascular risk factors and then trying to modify them, especially as the management of pre-diabetics and those detected at an early stage will probably be the same with lifestyle modification and drugs to treat insulin resistance and all the other culprits such as hypertension and hyperlipidaemia?
Some years ago, in my practice, we had a look at methods for screening. In our larger practice site we trawled the notes for patient with three or more risk factors and we invited them for fasting blood tests. In our smaller site we carried out a mass screen by invitation and had an 80 per cent uptake.
It rapidly became obvious that opportunistic screening was more practical and we have continued in third mode and have applied opportunistic screening to all risk factors for cardiovascular disease.
A patient with IFG would be asked to have a post-prandial test and vice versa. A glucose tolerance test feels passe.
Intuitively one feels screening for cardiovascular risk factors will be cost-effective with diabetes and increasingly pre-diabetes as just two of these risk factors. Dr Roger Boyle, the heart czar, is known to be enthusiastic about the ploypill and I think this gives a hint to the future.
I would urge practices to think in terms of abnormal glycaemic states as being simply part of the risk factor profile for all cardiovascular disease.
At some stage in the future I am sure
we will be required to have a register of pre-diabetic abnormal glycaemic states and we will probably gain points for demonstrating a limited progression to frank diabetes within the definition that exists at the time.
Dr RA Hutton