Aims: To explore glucose lowering response to insulin initiation or switch to insulin glargine in obese and non-obese individuals with type 2 diabetes mellitus (T2DM) and to examine weight gain and hypoglycaemic episodes in this group.
Methods: Post hoc subgroup analysis using data of obese and non-obese participants from a large multi-centre (4555 participants with T2DM), multi-national 24-week randomized controlled trial of investigator titrated insulin glargine versus patient self-managed titrated insulin glargine. This analysis was carried out to compare two subgroups: obese (> or =30 kg/m2) and non-obese (<30 kg/m2) participants.
Results: The mean body mass index (BMI) values were 33.7 kg/m2(n = 1833) and 25.9 kg/m(2)(n = 2755) in obese and non-obese subjects, respectively. There was a significant reduction in glycated haemoglobin (HbA1c) from baseline in both subgroups but no significant difference between subgroups (1.15 vs. 1.15%, p = 0.50). Overall, there was a 1.21 kg (s.d. 3.3) increase in weight in individuals who were non-obese and a 1.08 kg (s.d. 3.9) increase in obese individuals (p = 0.67). There was no significant difference in the proportion of participants achieving an HbA1c of <7.0% at 6 months in both the subgroups (28.8 vs. 27.1%, p = 0.20). In multiple logistic regression, BMI was not a prognostic factor in achieving a target of HbA1c < or = 7.0%. There was no significant difference in severe hypoglycaemic episodes between obese and non-obese subgroups (1.3 vs. 1.0%); however, significantly more non-obese individuals experienced nocturnal hypoglycaemic episodes(4.5 vs. 2.4%, p < 0.05).
Conclusions: In this study, treatment with insulin glargine in people with T2DM was associated with a significant reduction in HbA1c without differential increase in weight gain in obese and non-obese subgroups. Rates of severe hypoglycaemia were not different between obese and non-obese subgroups.
Trial registration: ClinicalTrials.gov NCT00399724.