Reducing snacks when switching from conventional soluble to lispro insulin treatment: effects on glycaemic control...

The lack of significant improvement in HbA1c during insulin lispro treatment in previous studies may have been due to inadequate dietary adjustments. We tested whether reduction of snacks and a compensatory increase in main meals results in improved metabolic control when switching to lispro treatment. One hundred and forty-one Type 1 diabetic patients, mean +/- SD age 36 +/- 9 years, diabetes duration 14 +/- 10 years, had two daily NPH injections throughout the study. After a baseline visit, the patients used conventional soluble insulin preprandially thrice daily for 12 weeks. Thereafter they were switched to lispro insulin and advised to transfer > or =50% of their snack carbohydrates to preceding main meals. Mean HbA1c at baseline was 8.05%. After the conventional period and the 12-week lispro period, HbA1c was 7.81 and 7.70% (p = 0.088), respectively. In those patients who diminished their snacks as advised (n = 67), HbA1c decreased from 7.91 to 7.66% (p = 0.014) during lispro, whereas no change was observed in patients not compliant with the dietary change. The number of hypoglycaemic episodes was lower during lispro period (blood glucose <2.5 mmol l(-1): 1.43 vs 2.19 episodes, p = 0.004; symptomatic nocturnal hypoglycaemia 1.16 vs 1.67 episodes, p<0.001). When switching from conventional soluble to lispro insulin, reduction of snack carbohydrates is safe and results in slightly improved HbA1c in patients who are fully compliant with the dietary change.