Continuous subcutaneous insulin infusion (CSII) is an effective therapy to control hyperglycemia in both patients with type 1 diabetes and type 2 diabetes. However, there is little data investigating the insulin dose setting during CSII therapy in type 2 diabetes to achieve optimal glycemic control and avoid the risk of hypoglycemia. Thus, this study is aimed to assess the dose characteristics of insulin requirement and explore the related clinical factors in patients with type 2 diabetes who were treated with CSII. A total of 327 patients (195 males) aged 52.9±12.5 years old were included in this study. Patients were treated with CSII to achieve the target fasting capillary blood glucose (4.4-7.0 mmol L-1) and 2-h postprandial capillary blood glucose (4.4-10.0 mmol L-1) by adjusting insulin infusion according to the seven-point capillary blood glucose profiles. Total daily insulin dose (TDD), total daily insulin dose per kilogram (TDD kg-1) and the ratio of total basal insulin dose (TBD) to TDD (%TBa) were calculated after patients achieved the glucose targets for at least 3 days via 1-2 weeks of CSII treatment. And insulin dose, insulin dosing patterns and the relevant clinical factors were analyzed. The mean ratio of basal/bolus insulin distribution of all patients was 40%:60%. Patients with central obesity needed more TDD (51.3±17.1 U versus 43.5±14.0 U, P<0.05) and TDD kg-1 (0.8±0.3 U kg-1 versus 0.7±0.2 U kg-1, P<0.05) than those without central obesity. Pearson's correlation analysis demonstrated that TDD was positively correlated with body mass index (BMI), waist circumference (WC), baseline fasting plasma glucose (FPG), fasting C-peptide level, 2 h-postprandial C-peptide level and time to achieve glycemic target (all P<0.05); TDD kg-1 was positively correlated with waist-to-hip ratio (WHR), baseline FPG, glycosylated hemoglobin A1c (HbA1c), fasting C-peptide level and time to achieve glycemic target, and negatively correlated with BMI (all P<0.05). Multiple linear regression analyses revealed that BMI (β=1.796, P<0.01), WC (β=0.709, P<0.01), baseline FPG (β=1.459, P<0.01) and HbA1c (β=0.930, P=0.021) were independently related to TDD. Gender (β=-0.107, P=0.003), WC (β=0.005, P=0.029), baseline FPG (β=0.025, P<0.01) and HbA1c (β=0.016, P=0.007) were independently associated with TDD kg-1. Gender (β=-0.015, P=0.048) and disease duration (β=0.134, P=0.029) were independently associated with %TBa. %TBa is around 40% in Chinese patients with type 2 diabetes treated with CSII when glycemic control is achieved. In addition to body weight or BMI, WC and glucose levels before CSII should be considered to set TDD. Patients with central obesity or poor glycemic control might need more TDD. Higher %TBa should be considered in female patients or patients with longer disease duration.
Keywords: continuous subcutaneous insulin infusion; insulin requirement profiles; type 2 diabetes.