The two long-acting insulin analogues (artificial insulins), insulin detemir or insulin glargine differ in their mechanism of attaining protracted action, leading to possible differences in glycaemic control and safety outcomes. Several studies have compared either insulin detemir or insulin glargine to NPH (Neutral Protamin Hagedorn) insulin. Research directly comparing both long-acting insulin analogues is limited.
Our aim was to systematically review the efficacy and safety of insulin detemir and insulin glargine in head-to-head studies in the treatment of type 2 diabetes mellitus.
Four studies investigated a total of 2250 people. Trials lasted between 24 and 52 weeks. Overall, risk of bias of the evaluated studies was high. Our analysis of these intermediate term trials comparing insulin detemir with insulin glargine showed that these two insulins were equally effective in achieving and maintaining glycaemic control (glycosylated haemoglobin A1c (HbA1c)). There were no differences in overall, nocturnal and severe hypoglycaemia when comparing insulin detemir to insulin glargine. Insulin detemir was associated with significantly less weight gain (one study showing a difference of 0.9 kg). Treatment with insulin glargine resulted in a lower daily basal insulin dose and a lower number of injection site reactions (1.8% of patients treated with insulin detemir compared to 0.4% of patients treated with insulin glargine had injection side reactions).
There was no difference in the variability of fasting glucose levels or the variability of glucose values of 24-hour profiles between the two treatment groups.
From the retrieved trials it was not possible to draw conclusions on the effects of these two insulins on quality of life, their costs or on the number of fatalities. Only one trial reported results on health-related quality of life and showed no significant differences between treatment groups.
Our analyses suggest that there is no clinically relevant difference in the efficacy or the safety between the use of insulin detemir and insulin glargine for treating type 2 diabetes mellitus. However, to achieve the same glycaemic control insulin detemir was often injected twice-daily in a higher dose but with less weight gain, while insulin glargine was only injected once-daily, with somewhat fewer injection site reactions.