Insulin Dosing in Type 2 Diabetes

See Also

Indications

See Type II Diabetes Mellitus
Insulin Augmentation (Basal insulin only starting at 0.1 to 0.3 units/kg)
1. Symptomatic Hyperglycemia or Hemoglobin A1C >9% despite non-Insulin therapy AND
  1. One or two oral Oral Hypoglycemic agents OR
  2. GLP-1 Agonist and at least one Oral Hypoglycemic agent
Insulin Replacement (basal and Bolus Insulin starting at 0.6 to 1.0 units/kg)
1. Blood Glucose >300 to 350 mg/dl OR
2. Hemoglobin A1C >10-12% OR
3. Failure to meet Blood Glucose goals despite Insulin Augmentation

Adverse Effects

Weight gain
1. Consider Basal insulin with GLP-1 Receptor Agonist, Metformin or Pamlintide to mitigate weight gain
2. Avoid other Medications Associated with Weight Gain
Hypoglycemia
1. See Hypoglycemia Management in Diabetes Mellitus
2. Patient Education on recognition and management of Hypoglycemia
3. Exercise caution when Hemoglobin A1C <7.4%, severe Renal Insufficiency
4. Do not use Insulin Secretagogues (e.g. Sulfonylureas, Meglitinide) with Bolus Insulin
5. Analogue basal (e.g. Lantus) and bolus (e.g. Lispro) agents are lower risk for Hypoglycemia than regular and NPH

Protocol
Identify Blood Glucose goals

No predisposition to Hypoglycemia (goals per ADA, and AACE/ACE in parentheses)
1. Pre-meal or Fasting: 80-130 mg/dl per ADA (or 70 to 110 mg/dl per AACE/ACE)
2. Two hour post-prandial Glucose <180 mg/dl per ADA (or 140 per AACE/ACE)
  1. Blood Glucose 20-40 mg/dl above pre-meal Glucose
3. Bedtime: 100-140
4. Hemoglobin A1C: <7-8% (Normal 4.0 - 6.0%)
Predisposition for Hypoglycemia (Comorbid conditions)
1. Pre-meal/Fasting: 100-150
2. Hemoglobin A1C: 7-8%

Protocol
Starting Basal Only Insulin (Augmentation) and Advancing to Basal/Bolus Insulin (Replacement) in Type II Diabetes

Precautions
1. Requires regular Blood Glucose Monitoring and compliant, reliable patient and family
2. Educate on home Hypoglycemia Management (Glucose tablets, Glucagon)
Step 0: 0-0-0-G (Basal Only Protocol - Insulin Augmentation)
1. Basal insulin
  1. Preparations
    1. Insulin Glargine (G) such as Lantus, Levemir or
    2. NPH (if cost is a concern)
      1. Also start with single dose at bedtime (despite shorter half life)
  2. Starting dose options
    1. Basal insulin 10 units at night OR
    2. Basal insulin 0.1 to 0.2 units/kg/day (or 50% of total daily sliding scale dose)
  3. Titrate
    1. Increase Basal insulin by 2-4 units or 10-15% once or twice weekly until Blood Glucose controlled
    2. Go to Step 1 when Blood Glucose not at goal despite Basal insulin >0.5 units/kg/day
    3. Hypoglycemia should prompt decrease Insulin 4 units or 10-20% (and address cause)
2. Other agents to continue
  1. Oral Insulin sensitizer (e.g. Metformin or Glucophage) and
  2. Oral Insulin Secretagogue (e.g. Glipizide)
    1. Stop when Bolus Insulin (e.g. RA) is initiated more than once daily
Step 1: 0-0-RA-G (Basal Plus Protocol)
1. Indications
  1. Hemoglobin A1C targets not met despite Basal insulin
  2. Basal insulin >0.5 units/kg/day
2. As an alternative, may use premixed Insulin twice daily (see protocol below)
3. Add 0.1 units/kg (or 4 units or 10% of basal dose) Bolus Insulin before largest meal
  1. Lispro or Aspart (rapid acting or RA) or
  2. Regular Insulin (if cost is a concern)
    1. Avoid in Stage IV or Stage V significant Chronic Kidney Disease
    2. Avoid if history of severe Hypoglycemia
4. Other dosing
  1. Decrease Insulin Glargine by 0.1 units/kg if Hemoglobin A1C <8%
  2. Continue Insulin sensitizer (e.g. Metformin)
  3. Caution with Insulin Secretagogue (e.g. Glipizide)
    1. May be continued with caution once per day opposite the rapid acting Insulin dose
    2. Consider discontinuing in the elderly or other risks of Hypoglycemia
5. Titration
  1. Check Blood Glucose Fasting, before rapid acting (RA) dose and at bedtime
  2. Increase Bolus Insulin by 1-2 units or 10-15% once or twice weekly until Blood Glucose controlled
  3. Hypoglycemia should prompt decrease Insulin 2-4 units or 10-20% (and address cause)
Step 2: RA-0-RA-G (Basal-Bolus Protocol)
1. Add 0.1 units/kg (or 4 units or 10% of basal dose) rapid acting (RA) Bolus Insulin before 2nd largest meal
2. Decrease Insulin Glargine by 0.1 units/kg if Hemoglobin A1C <8%
3. Continue Insulin sensitizer (e.g. Metformin)
4. Stop Insulin Secretagogue (e.g. Glipizide, Meglitinide)
5. Check Blood Glucose Fasting, before rapid acting (RA) doses and at bedtime
Step 3: RA-RA-RA-G (Basal-Bolus Intensive Protocol)
1. Add 0.1 units/kg (or 4 units or 10% of basal dose) rapid acting (RA), Bolus Insulin before 3rd largest meal
2. Decrease Insulin Glargine by 0.1 units/kg if Hemoglobin A1C <8%
3. Check Blood Glucose Fasting, before rapid acting (RA) doses and at bedtime
Precautions
1. Keep Insulin split into 50% basal and 50% bolus

Protocol
Starting Basal insulin (e.g. Lantus) and Bolus Insulin (e.g. Lispro)

Step 0: Adjust oral medications
1. Stop Insulin Secretagogue (Sulfonylurea, Meglitinide) when on twice daily Bolus Insulin
2. Continue Insulin sensitizers (Metformin, Glitazone)
Step 1: Choose a 24 hour Basal insulin (once daily):
1. Detemir (Levemir)
2. Glargine (Lantus)
Step 2: Choose a Bolus Insulin (pre-meal Insulin):
1. Regular Insulin (Novolin R, Humulin R)
2. Glulisine (Apidra)
3. Lispro (Humalog)
4. Aspart (Novolog)
Step 3: Starting dose
1. Hemoglobin A1C <8
  1. Basal insulin 0.1 units/kg once daily AND
  2. Bolus Insulin 0.1 units/kg divided equally before meals (start before breakfast and dinner)
2. Hemoglobin A1C 8-10
  1. Basal insulin 0.2 units/kg once daily AND
  2. Bolus Insulin 0.2 units/kg divided equally before meals (start before breakfast and dinner)
3. Hemoglobin A1C >10
  1. Basal insulin 0.3 units/kg once daily AND
  2. Bolus Insulin 0.3 units/kg divided equally before meals (start before breakfast and dinner)

Protocol
Starting Basal/Bolus Insulin using NPH

Background
1. Other regimens less complicated and therefore preferred
2. However, NPH and Regular Insulin are least expensive Insulin options
Step 0: Adjust oral medications
1. Stop Insulin Secretagogue (Sulfonylurea, Meglitinide) when on twice daily Bolus Insulin
2. Continue Insulin sensitizers (Metformin, Glitazone)
Step 1: Starting dose
1. Hemoglobin A1C <8: Total Insulin: 0.1 units/kg in AM and 0.1 units/kg in PM
2. Hemoglobin A1C 8-10: Total Insulin: 0.2 units/kg in AM and 0.2 units/kg in PM
3. Hemoglobin A1C >10: Total Insulin: 0.3 units/kg in AM and 0.3 units/kg in PM
Step 2: Divide each Insulin dose into 1/3 bolus (e.g. Regular Insulin) and 2/3 NPH Insulin
Step 3: Schedule 2 doses of Bolus Insulin (e.g. regular) and 2 doses of NPH daily
1. Breakfast (50%): NPH Insulin (2/3) and Regular Insulin (1/3)
2. Dinner (50%): NPH Insulin (2/3) and Regular Insulin (1/3)

Protocol
Starting Insulin using Premixed Insulin

Step 0: Adjust oral medications
1. Stop Insulin Secretagogue (Sulfonylurea, Meglitinide)
2. Continue Insulin sensitizers (Metformin, Glitazone)
Insulin preparations (for twice daily dosing)
1. Lispro Mix 75/25 or
2. Aspart Premix 70/30
Starting dose
1. Based on Insulin Glargine Regimen (Insulin Augmentation) as above
  1. Divide current Basal insulin dose into 2/3 AM and 1/3 PM or
  2. Divide current Basal insulin dose into 1/2 AM and 1/2 PM
2. Based on current Hemoglobin A1C
  1. A1C <8: 0.1 units/kg in AM and 0.1 units/kg in PM
  2. A1C 8-10: 0.2 units/kg in AM and 0.2 units/kg in PM
  3. A1C >10: 0.3 units/kg in AM and 0.3 units/kg in PM
Titration
1. Check Blood Glucose Fasting, before Insulin dose and at bedtime
2. Increase Insulin by 1-2 units or 10-15% once or twice weekly until Blood Glucose controlled
3. Hypoglycemia should prompt decrease Insulin 2-4 units or 10-20% (and address cause)

Protocol
Converting from Premixed Insulin to Basal Bolus Insulin

Calculate total Insulin units/kg
1. Total >1.5 units/kg: Lower total to 1.0 unit/kg
2. Hemoglobin A1C <9: Decrease total Insulin by 10%
Divide total Insulin Dosing
1. Insulin Glargine: 50% of total Insulin
2. Rapid acting: 50% of total divided across meals

Protocol
Insulin Adjustments

References

Howard-Thompson (2018) Am Fam Physician 97(1):29-37
Inzucchi (2015) Diabetes Care 38(1): 140-9 [PubMed]