UK study boosts drive for GP insulin initiation
By Adam Legge
The push for GP insulin initiation in type 2 diabetes looks set to step up a gear in the wake of a large UK study that proved the effectiveness of a simple dose calculator.
The study, headed by the lead researcher behind the landmark UK Prospective Diabetes Study, found the calculator reduced the need for cumbersome dose titration and with a low risk of hypoglycaemic attacks.
Data from the Treating to Target in Type 2 Diabetes (4-T) trial was presented at the European Association for the Study of Diabetes in Amsterdam last week and published in the New England Journal of Medicine.
Some 708 UK patients on maximum doses of metformin and sulphonylurea were randomised to receive biphasic, prandial or basal insulin.
One-year figures from the three-year trial show that basal insulin was the least effective regime in lowering HbA1c but was associated with less weight gain and hypoglycaemic risk.
Prandial insulin three times a day had the greatest risk of hypoglycaemia and weight gain but cut HbA1c the most (see box right).
Initial dose was calculated using an insulin initiation tool, developed by lead author Professor Rury Holman, director of the Diabetes Trials Unit at the Oxford Centre for Diabetes, Endocrinology and Metabolism.
He said: ‘This shows you can start patients on varying insulin doses, from two to 76 units a day, without hypos posing a major problem.'
The tool – which uses a patient's fasting blood glucose, height and weight to calculate number of units a day – will be validated and simplified further to encourage its use.
But Dr Martin Hadley-Brown, a GP in Norfolk and chair of the Primary Care Diabetes Society, said: ‘I like it as it stands, and it should help to demystify the use of insulin in primary care and ensure the people who need it, get it.'
Dr Hadley-Brown added the 4-T data on the effects of different insulins would be useful.
‘For instance a patient with a HbA1c of less than 8.5 could be started on basal, while someone over 8.5 would ideally start on a biphasic unless weight gain is a major issue.'
Dr Andrew Farmer, co-author of 4-T and a GP in Oxford, agreed, saying: ‘This shows adding insulin to type 2 diabetes treatment is feasible with three-monthly surgery visits.'
He added the results probably ruled out prandial insulin for routine use in primary care, but both basal and biphasic were manageable options.Insulin dose calculator