Factors that influence basal insulin requirement in type 2 diabetes

In clinical practice, basal insulin dosage (BID) for the treatment for type 2 diabetes given as slow-acting analogues or NPH insulin varies widely when adjusted for body weight (UI/kg). In this study, we investigated the interrelationship between BID and anthropometric, laboratory and clinical parameters. A total of 681 type 2 diabetic patients, treated with bedtime insulin in association with other antidiabetic drugs (preprandial insulin and/or oral agents), were studied. Anthropometric, clinical and biochemical parameters, as well as micro- and macrovascular complications, were evaluated. Non-alcoholic fatty liver disease (NAFLD) was assessed by liver ultrasound. BID was titrated to achieve a fasting blood glucose target of ≤6.7 mmol/L (120 mg/dL). In the multivariate analysis, BID was significantly associated with waist circumference (p = 0.04) and the insulin treatment duration (p = 0.004) as the type of insulin treatment ("basal-bolus" regimen vs. basal insulin only, p < 0.0001), the use of lipid-lowering drugs (p = 0.0003) and insulin sensitizers (p = 0.005). Several glycometabolic parameters were strongly associated with BID (HbA1c p = 0.01, FPG p < 0.0001, HDL p = 0.02, triglycerides p = 0.03). Moreover, the presence of severe NAFLD resulted in a higher BID (p = 0.03). We concluded that when starting and titrating the basal insulin in type 2 diabetes, certain anthropometric, laboratory and clinical factors can be useful to find optimal BID more quickly and appropriately.