Insulin Therapy for Diabetes Management

Introduction to Basal-Bolus Regimen

The American College of Physicians recommends using a combination of basal and prandial insulin to optimize glycemic control and reduce morbidity and mortality in patients with diabetes, as this combination addresses both basal and prandial/post-prandial glucose control needs 1, 2

The American Diabetes Association suggests that Novolog 70/30 should be administered twice daily, 30 minutes before breakfast and dinner, to provide both immediate and extended glucose control 3
The combination of Lantus and Novolog 70/30 provides comprehensive 24-hour coverage, with Lantus providing consistent background insulin and Novolog 70/30 covering mealtime and post-meal glucose excursions 4, 5

The Endocrine Society recommends initiating Lantus at 10 units or 0.1-0.2 units/kg of body weight, and Novolog 70/30 at 10 units or 0.1-0.2 units/kg of body weight per day, divided into two equal doses, with dose titration based on self-monitored blood glucose readings 1, 2, 3
Dose adjustments should be made based on fasting glucose readings for Lantus, and pre-meal and post-meal glucose readings for Novolog 70/30 2, 3

The American College of Cardiology notes that this combination provides better postprandial glucose control compared to basal insulin alone, and allows for more flexible meal planning than using premixed insulin alone 4, 5
Studies have demonstrated that adding prandial coverage to basal insulin improves overall glycemic control when basal insulin alone is insufficient, with a strength of evidence rated as high 6

Regular monitoring of both fasting and postprandial glucose levels is essential, with HbA1c evaluated every 2-3 months to assess overall glycemic control 1, 2, 3
If glycemic targets are not achieved, adjustments should be made to Lantus and Novolog 70/30 doses based on glucose readings, with consideration of adding a third dose of Novolog 70/30 if needed for additional meal coverage 2, 3, 6

The risk of hypoglycemia may increase when using multiple insulin formulations, and careful monitoring is required, with a strength of evidence rated as moderate 4, 5
Overlapping insulin action times may occur between the protamine component of Novolog 70/30 and Lantus, and dose adjustments may be needed to prevent hypoglycemia, with a strength of evidence rated as low 4, 6
Metformin therapy should be continued when possible, but sulfonylureas and DPP-4 inhibitors are typically discontinued when using this combination insulin regimen, with a strength of evidence rated as high 6

When basal insulin has been titrated to an acceptable fasting blood glucose level but A1C remains above target, advancing to combination injectable therapy is recommended, as suggested by the American Diabetes Association guidelines 7
For patients with suboptimal blood glucose control requiring large insulin doses, adjunctive use of a thiazolidinedione or an SGLT2 inhibitor may help improve control and reduce the amount of insulin needed, according to the American Association of Clinical Endocrinologists 7
If glycemic targets are not achieved with the current regimen, consider switching to a more intensive basal-bolus regimen with multiple daily injections of rapid-acting insulin, as recommended by the American Diabetes Association 7
Adding a GLP-1 receptor agonist can be considered for treatment intensification, as it has potent glucose-lowering actions with less weight gain and hypoglycemia compared to intensified insulin regimens, based on guidelines from the American Diabetes Association 7