Efficacy and treatment satisfaction of once-daily insulin glargine plus one or two oral antidiabetic agents versus continuing premixed human insulin in patients with Type 2 diabetes previously on long-term conventional insulin therapy: the SWITCH Pilot Study.

Background: Addition of the long-acting basal human insulin analogue insulin glargine (LANTUS) to the treatment regimen of patients with inadequate glycaemic control on oral antidiabetic drugs (OADs) alone has previously been evaluated as effective, safe and convenient. This pilot study aimed to establish whether insulin glargine plus OADs is effective in Type 2 diabetes patients previously poorly controlled on premixed insulin therapy.

Methods: In an open, controlled, randomized, parallel-group, single-centre, 16-week pilot study, 52 patients (age 65.6+/-9.2 years; diabetes duration 15.3+/-7.6 years; insulin therapy duration 4.2+/-1.7 years, body mass index 31.4+/-2.9 kg/m(2)) with Type 2 diabetes (HbA (1c)> or =8.0%) on premixed human insulin (75/25 or 70/30) were randomized to once-daily morning insulin glargine plus glimepiride (Group A; n=17), insulin glargine plus glimepiride and metformin (Group B; n=18) or premixed insulin (Group C; n=17). Glycaemic control and incidence of hypoglycaemia were evaluated.

Results: HbA (1c) decreased significantly from baseline in Groups A and B, but not in Group C; (Group A: 7.87+/-0.66%, -0.35%, p=0.013; Group B: 7.44+/-0.92%, -0.69%, p=0.0057; Group C: 7.83+/-1.13%, -0.25%, p=0.32). There were no between-treatment differences at endpoint in HbA (1c), fasting blood glucose, mean daily blood glucose or symptomatic hypoglycaemia (mean events/patient: Group A, 2.2; Group B, 2.3; Group C, 2.0). At endpoint, 88% of patients in Group A, 81% in Group B and 94% in Group C opted to continue with their assigned regimen.

Conclusions: This pilot study is the first prospective study to show that switching from premixed insulin to insulin glargine plus OAD treatment resulted in similar glycaemic control and treatment satisfaction. The results support the need for prospective examination in a larger-scale clinical study in patients with long-standing Type 2 diabetes and sub-optimal glycaemic control previously using a conventional premixed insulin regimen.