What is the appropriate dose and type (regular vs. basal) of insulin for a patient with uncontrolled diabetes and an HbA1c (Hemoglobin A1c) level of 8%?

From the Guidelines

Insulin Therapy for Uncontrolled Diabetes

For a patient with uncontrolled diabetes and an HbA1c of 8, initiation of insulin therapy is recommended. A suitable starting regimen is basal insulin, such as glargine (Lantus) or detemir (Levemir), at a dose of 10 units once daily [ 1 ], with the option to add rapid-acting insulin, such as aspart (Novolog) or lispro (Humalog), at a dose of 4-6 units before meals if necessary.

Key Considerations

• The initial basal insulin dose can be adjusted based on fasting glucose levels, with a goal of achieving a level below 130 mg/dL [ 1 ].
• Cost considerations are important when selecting an insulin product, particularly due to substantial price increases over the past decade [ 1 ].
• Premixed insulin products containing both basal and bolus insulin are another option for patients who may benefit from simpler dosing [ 1 ].
• Rapid-acting insulin analogues are preferred for premeal insulin dosing due to their quick onset of action [ 1 ].

Adjusting Insulin Dose

• The dose of basal insulin can be increased by 10% to 15%, or 2 to 4 units, once or twice weekly until the fasting blood glucose target is met [ 1 ].
• If the HbA1c target is not met, the regimen can be intensified by adding a single injection of rapid-acting insulin before the largest meal or switching to a basal-bolus insulin regimen [ 1 ].

Final Recommendations

• Providers should consider regimen flexibility when devising a plan for the initiation and adjustment of insulin therapy for patients with type 2 diabetes [ 1 ].
• Regular monitoring of blood glucose levels and adjustment of the insulin dose as needed is crucial to achieve optimal glycemic control [ 1 ].

From the FDA Drug Label

To evaluate the administration of HUMALOG via external insulin pumps, two open-label, crossover design studies were performed in patients with type 1 diabetes. One study involved 39 patients, ages 19 to 58 years, treated for 24 weeks with HUMALOG or regular human insulin. After 12 weeks of treatment, the mean HbA1c values decreased from 7.8% to 7.2% in the HUMALOG-treated patients and from 7.8% to 7.5% in the regular human insulin-treated patients.

The appropriate dose and type of insulin for a patient with uncontrolled diabetes and an HbA1c level of 8% cannot be directly determined from the provided drug label, as the label does not provide specific dosing recommendations for this HbA1c level.

• Key points:
  • The label discusses the use of HUMALOG (lispro) in patients with type 1 diabetes.
  • It mentions that HUMALOG achieved glycemic control comparable to Humulin R (regular human insulin) in clinical studies.
  • However, it does not provide a clear recommendation for the dose and type of insulin for a patient with an HbA1c level of 8%.
• Clinical decision: Given the lack of direct information, a conservative clinical decision would be to consult additional resources or clinical guidelines to determine the appropriate dose and type of insulin for this patient. 2

From the Research

Insulin Dosing for Uncontrolled Diabetes

• The appropriate dose and type of insulin for a patient with uncontrolled diabetes and an HbA1c level of 8% can be determined based on several factors, including the patient's current treatment regimen, glucose levels, and individualized goals 3, 4, 5.
• Basal insulin is usually initiated at a conservative dose of 10 units/day or 0.1-0.2 units/kg/day, and then titrated thereafter based on patients' self-measured fasting plasma glucose to achieve an individualized target of 80-130 mg/dL 3.
• For patients with type 2 diabetes, insulin is considered alone or in combination with oral agents when HbA1c is ≥ 7.5%, and is essential for treatment in those with HbA1c ≥ 10% 4.
• The preferred method of insulin initiation in type 2 diabetes is to begin by adding a long-acting (basal) insulin or once-daily premixed/co-formulation insulin, alone or in combination with other oral antidiabetic drugs 4.

Titration and Adjustment of Insulin Regimen

• Insulin regimens should be adjusted every three or four days until targets of self-monitored blood glucose levels are reached 5.
• Fasting and premeal blood glucose goals of 80 to 130 mg per dL and a two-hour postprandial goal of less than 180 mg per dL are recommended 5.
• If the desired glucose targets are not met, rapid-acting or short-acting (bolus or prandial) insulin can be added at mealtime to control the expected postprandial raise in glucose 4, 6.
• Intensifying insulin therapy by adding one dose of rapid-acting insulin prior to meals can improve HbA1c to < 7% in patients on maximum doses of basal insulin whose fasting blood glucose is at goal but whose HbA1c is above goal 6.

Comparison of Insulin Regimens

• A study comparing the efficacy and safety of treating patients with type 2 diabetes and highly elevated HbA1c levels with basal-bolus insulin or a glucagon-like peptide-1 receptor agonist plus basal insulin found that treatment with GLP1RA plus basal insulin resulted in better glycemic control and body weight, lower insulin dosage and hypoglycaemia, and improved quality of life 7.
• Insulin analogues are as effective as human insulin at lowering A1C levels with lower risk of hypoglycemia, but they have significantly higher cost 5.