Efficacy and Safety of Frequently Modified Intensive Insulin

Insulin treatment is the mainstay of Type-1 diabetic management and one of the cornerstones in Type-2 diabetes. This treatment is based on multiple daily injections of different types of insulin. Patients follow their endocrinologists' directions by adhering to a set of recommended dosages and formulas, calculated by repeated blood glucose measurements. In order to maintain effective and safe management, glucose measurements are taken before meals and at bedtime, albeit imposing a heavy financial burden on a patient and their support system. For illustration, each disposable glucosemeter strip costs more than a dollar and needs to be replaced routinely 4 times daily, yielding an annual cost of more than $1500 per patient. Insulin dosages necessitate repeated adjustments to meet the patient's changing needs. Variations in food intake, body weight, physical activity, on going medical conditions and mood can impact a patient's insulin needs.

Accordingly, at each diabetic clinic appointment, the endocrinologist reviews the patient's glucose measurements and insulin doses to determine whether the insulin dosage needs to be adjusted. Unfortunately, limited appointment availability restricts insulin dosages adjustments to once every several months. Furthermore, as a result of the limited time allotted for each patient, new dosing recommendations are based on a review of only the most recent measurements. This drawback may be one of the chief causes of suboptimal management, with merely 38% of diabetic patients able to achieve proper control and mitigate detrimental complications.

Since the discovery of insulin by Frederick Grant Banting in 1921, only stringent glucose control by a regimen of multiple insulin injections has prevented microvascular and macrovascular complications in Type 1 diabetic patients. Moreover, insulin treatment amongst other treatment modalities has been shown to prevent microvascular and macrovascular complications in Type-2 diabetic patients. Incidentally, as the Type-2 diabetic epidemic expands, insulin treatment is becoming one of the main treatment modalities. Not taking into consideration availability, it has been established that more frequent patient-clinic interactions improve diabetic management in both Type-1 and Type-2 patients.

In a typical 3-6 month interval appointment, the endocrinologist would measure a patient's hemoglobin A1c (HbA1c) to determine the quality of the last 3 months control. This value, is linearly correlated to mean glucose levels at that 3 months period and, therefore, can be predicted according to the measurements. We used anonymous records of glucose measurements to perform preliminary statistical analysis. Our results indicate that a patient's glucose level is a highly non-stationary process, with strong variations in both mean and standard deviation (SD) from one week to another. In many patients with excessive HbA1c, which are at levels that diabetic complications are likely to ensue, the endocrinologist is obligated to adjust the insulin dosage based on a review of the patient's most recent glucose values and the values of the past several weeks. Furthermore, since appointment timing is random and independent from the patient's measurements, random trends in glucose values may be identified that lead to different conclusions. For illustration, if a patient's appointment happens to occur when his glucose values randomly trend up, the endocrinologist may choose to increase insulin doses. On the other hand, if the appointment occurs at a time when the glucose levels trend down, he may act oppositely. The required frequency of follow-up and dose adjustment that yields better patient control is yet to be determined.

Studies have shown that case management in patients with Type-2 diabetes can allow better control of HbA1c levels. These studies have involved using qualified medical professionals (ie, nurses, pharmacists, physician's assistants) as intervention methods, as well as providing counseling and follow-up calls to help patients with improved self-management of diabetes.

This study is designed to show that weekly insulin dosage adjustments for intensive insulin therapy are superior to conservative, infrequent adjustments during clinical appointments in both Type-1 and Type-2 diabetes.