2191-PUB: Challenging the 50%/50% Basal/Bolus Insulin Ratio Rule: Have We Been Wrong? A Cross-Sectional Study

Abstract

There is a generally-held belief that the ratio between basal and bolus insulin requirements in patients using insulin therapy should be 50%/50%. Yet, it appears this belief was based on a small study with healthy individuals, which may not be applicable to patients with insulin deficiency. To assess the validity of the rule we followed patients with type 2 diabetes treated with basal-bolus insulin therapy that has been frequently adjusted by a technology-based titration service. To keep glycemia stable, the service adjusts insulin dosage at least weekly and thus treatment closely tracks insulin requirements. We performed a cross-sectional study, accumulating data on N=306 patients over an average±SD period of 3.4±1.7 years. Insulin titrations occurred every 6.8±1.5 days to enable HbA1c maintenance at 7.2±0.7%. In 74.8% of the patients the average basal insulin fraction was less than 50% of total daily dose of insulin, and in about a third it was less than 38% (Figure). Additionally, the basal fraction did not remain stable in each patient over time (Figure). In 79.7% of the patients, it changed more than 20% and in 50% more than 29.8% (e.g., basal fraction changes in a single patient would range between 20% and 50% over time). In patients with type 2 diabetes treated with insulin, basal-bolus ratio is not 50%/50% and it changes over time. Thus, this ratio should not be used as a treatment guide. Disclosure I. Hodish: Stock/Shareholder; Self; Hygieia. M. Willis: Employee; Self; Hygieia. S. Sritharan: None. E. Bashan: Employee; Self; Hygieia. Stock/Shareholder; Self; Hygieia.