Safety and efficacy of basal-bolus insulin regimen vs premixed insulin regimen among type 2 Diabetes mellitus (T2DM) patients : an observational study

Abstract

Type 2 Diabetes Mellitus (T2DM) is a chronic condition due to insulin resistance or relative insulin deficiency. In Malaysia, although various insulin regimens are recommended for the management of T2DM, premixed (PM) regimen is relatively more commonly prescribed compared to Basal-Bolus (BB) regimen probably due to the convenience of injecting fewer number of injections per day. Yet, there is still limited comparison data regarding the optimal use of these two regimens. Thus, the BB and PM insulin regimens were compared in regards to their safety and efficacy outcomes. A retrospective study involving 271 T2DM subjects treated with BB or PM regimen in an outpatient setting was conducted in Hospital Tengku Ampuan Afzan and Klinik Kesihatan Beserah observing patient data over one year period. Among the safety outcomes measured was the mean increment in weight, number of patients experiencing hypoglycemia, hospitalization rate and mortality rate. Consequently, efficacy outcomes measured were mean reduction in the Glycosylated Haemoglobin (HbA1c), mean reduction in the Fasting Plasma Glucose (FPG), and mean increment in the Total Daily Insulin (TDI) dose. After one year, mean reduction in HbA1c for BB versus that of the PM regimen was 0.9% versus 0.2% (difference: 0.66, 95% CI -0.06, 1.37, p=0.070), showing no significant difference between the arms. Also, there was no statistical significant difference between BB and PM arm in terms of mean reduction in FPG over a year,0.7 mmol/L versus 0.9 mmol/l (difference: 0.25, 95% CI –2.02, 1.52, p = 0.780), and mean increment in the TDI Dose, 15.1 U/day versus 11.8 U/day (difference: 3.37, 95% CI -8.38, 1.64, p = 0.184). On safety parameters, the difference between BB and PM arm in terms of number of patients experiencing hypoglycemia was 25.6% versus 17.1% (p=0.108) and the mean increment in weight was 0.9 kg versus 1.3kg (p = 0.581) , showing both parameters to be comparable over the one year period. Even though it was found that a significantly higher number of patients were hospitalized over the one year in the BB arm compared to the PM arm, hospitalization specifically due to hypoglycemia with 3 subjects in BB arm versus none in PM arm was found to be statistically not significant (p=0.245).No mortality was reported in either arm. From this first local comparative analysis of these two insulin regimens, it can be concluded that the BB regimen and PM regimen were equally safe, effective and comparable for use in T2DM patients at the involved study sites. Nevertheless, it is recommended for further research that such study should use larger sample size and extend the scope of study to other states in Malaysia.