Comparison of insulin glargine versus NPH insulin in people with type 2 diabetes mellitus under outpatient-clinic conditions for 18 months using a basal-bolus regimen with a rapid-acting insulin analogue as mealtime insulin

Aims: To assess the effects of a Structured inpatient diabetes training programme in people with Type 2 diabetes mellitus on a basal-bolus regimen using insulin glargine or NPH insulin and rapid-acting insulin analogues with respect to glycaemic control, weight development and incidence of hypoglycaemia in an outpatient-clinic setting. Patients and Methods: This was a prospective, non-randomized, single centre, comparative observational study including 119 subjects. Prestudy treatment was a basal-bolus regimen with NPH insulin and a rapid-acting insulin analogue. Subjects either continued with NPH insulin (n = 56) or were switched over to insulin glargine (n = 63) at the discretion of the investigator (aiming at equal numbers in each group). Patients then attended routine out-patient follow up visits for 18 months. Results: HbAlc in the insulin glargine group improved statistically significant by -0.49%; [95%CI, -0.26, -0.71; p < 0.001; HbA1c at endpoint 6.95 +/- 0.71 %], whereas in the NPH group the reduction by -0.12% [95%CI, -0.31, 0.06; p = 0.189; HbA1c at endpoint 7.22 +/- 0.74%] was statistically not significant. After 18 months of treatment the difference between treatment groups was 0.37% (p<0.015). Mean weight gain was significantly higher in the NPH group than in the glargine group (2.1 vs. 0.25 kg; p = 0.025). A lower risk of hypoglycaemia in the glargine group (0.50 vs. 0.71 episodes/patient/month) did not reach statistical significance (p = 0.081). Conclusions: Following a structured in-patient diabetes training programme glycaemic control in people with Type 2 diabetes mellitus on a basal-bolus regimen improved significantly only with insulin glargine suggesting that training alone may not be sufficient to further improve metabolic control in relatively well controlled patients on NPH insulin. Therefore, in addition to a structured training programme also the insulin regimen should be optimized, e.g. by introduction of an insulin analogue.