A novel approach to basal-bolus insulin initiation in adults with newly diagnosed type 1 diabetes: an observational cohort study of a service redesign

Abstract

Aims: The National Institute for Health and Care Excellence (NICE) recommendation for insulin in newly diagnosed type 1 diabetes is a ‘basal-bolus’ regimen of prandial insulin with twice-daily basal insulin initiated at diagnosis. We developed an insulin initiation programme that embraces the contribution of endogenous insulin to glycaemic control in adults newly diagnosed with type 1 diabetes. Our aim was to embed carbohydrate counting skills and dose adjustment very early on to mitigate against the decline in glycaemic control that is commonly seen post honeymoon.Methods: We designed a novel insulin initiation programme that focused initially on prandial insulin replacement using the lowest possible dose of basal insulin. The approach also facilitates carbohydrate counting and bolus insulin dose adjustment behaviours from diagnosis.Results: Prior to implementing the new programme, the mean HbA1c at 12 months was 64 mmol/mol (8.0%) (95% CI 60 to 69 (7.6% to 8.4%)). This reduced to 55 mmol/mol (7.1%) (95% CI 51 to 58 (6.9% to 7.4%)), p<0.001 with the new programme. The improved HbA1c persisted to 3 years of follow-up (p<0.001). There were no episodes of diabetic ketoacidosis or severe hypoglycaemia associated with this novel approach.Conclusions: We suggest that using minimal basal insulin and focusing on prandial bolus insulin replacement in adults newly diagnosed with type 1 diabetes is safe, more physiological and may be better able to achieve lasting glycaemic control than the currently proposed national guidelines. This approach will need to be tested formally in an adequately designed randomised controlled clinical trial.