Introduction:
We aimed to see whether insulin glargine U300 can provide better blood glucose control while reducing hypoglycaemia in a more homogeneous population compared to previous studies.

Material and methods:
The retrospective study included type 1 diabetes mellitus (T1DM) patients with frequent hypoglycaemia. For evaluation of fasting blood glucose, haemoglobin glycated (HbA1c) and weight at 6 months and 12 months (final), observation windows of 120–240 days (4–8 months) and 240–480 days (9–16 months) after insulin glargine U300 initiation, respectively, were permitted. Mean follow-up time was 12 months. Hypoglycaemia was defined as blood glucose level < 70 mg/dl, either symptomatic or asymptomatic, measured in hospital or at home.

Results:
Forty-four patients were included in the study, and 35 patients completed the study – 20 (57.1%) females and 15 (42.9%) males, with a mean age of 24.1 ±6.6 years. Mean body mass index was 24.4 ±7.4 kg/m2. A significant decrease was not found between baseline and HbA1c values at 6 months (p = 0.199), but a significant decrease was found in the final period (between 9–16 months) (p = 0.025). Hypoglycaemic events occurred in all patients (100%) before using insulin glargine U300, while the incidence of hypoglycaemic events gradually decreased to 74.3%, 68.6%, and 68.6% between months 1–3, 3–6, and 6–9, respectively. Of the 26 patients who declared their level of satisfaction, 23 (88.5%) were satisfied, 2 (7.7%) indicated that there was no significant difference, and 1 (3.8%) patient was unsatisfied.

Conclusions:
Over 9–16 months of follow-up, insulin glargine U300 led to a significant reduction not only of HbA1c levels but also of the frequency of hypoglycaemia, and also yielded high satisfaction rates.