Are Glucose Readings Sufficient to Adjust Insulin Dosage?

Abstract

Aims/hypothesis: Insulin therapy is effective predominantly when dosage is frequently adjusted. However, a controversy surrounds the pertinent clinical parameters required to make effective and safe frequent dosage adjustments. We hypothesize that glucose readings are sufficient to adjust insulin dosage provided that dosage is adjusted every 1-4 weeks. Methods: To test the hypothesis, we generated several algorithms implemented in software to process glucose readings and recommend insulin dosage adjustments. A post hoc analysis was made on 630 log sheets (2,520 insulin dosage adjustments) from 26 older adults with suboptimally controlled type 2 diabetes. The subjects were followed for a year and treated with intensive insulin therapy that was titrated every 1-4 weeks by a trained study team. More than 88% of subjects attained the treatment goal (hemoglobin A1c <7%) without excessive hypoglycemia. Glucose readings from each log sheet were used as an input to the software, and its recommendations for insulin dosage adjustments were compared to the original ones made by the study team. While the study team could have been exposed to multiple clinical parameters, the software relied solely on glucose readings. Results: The software recommendations for dosage adjustments were clinically equivalent to the original study team's recommendations in more than 95% of the cases, unrelated to patients' insulin sensitivity. The remaining 4.4% (n = 111) were thoroughly examined, yet we did not find any recommendations suggested by the software to be unsafe or unreasonable. Conclusions/Interpretation: Glucose readings are sufficient to effectively adjust insulin dosage provided that adjustments are made every 1-4 weeks. Therefore, dedicated software can help adjusting insulin dosage between clinic visits.