Insulin Dosing

See Also

Precautions

Insulin sensitivity varies throughout the day as well as with Puberty, pregnancy, illness and aging
Insulin doses are adjusted for planned Exercise, current Blood Glucose, and expected Carbohydrate intake

Protocols

Protocol
Goal Blood Glucose for Type I and Type II Diabetes

Hemoglobin A1C <7%
Goal: >50% of Blood Sugars in range
1. Pre-meal Blood Glucose 70-120 mg/dl
2. Two hour post-prandial Blood Glucose <160 mg/dl
3. Bed-time Blood Glucose 100-140 mg/dl

Evaluation
Blood Sugars

Monitoring pointers
1. Be consistent in monitoring
2. Aim for 50% of Blood Glucoses in target range
Look for consistent pattern in Blood Sugars for >3 days
1. Compare Blood Sugar for same time each day
2. For each time of day:
  1. Calculate Blood Glucose range
  2. Calculate median Blood Glucose
3. Consider eating and activity patterns during day
4. Ignore spurious values
Adjust only one Insulin dose at a time
1. Correct Hypoglycemia first
2. Correct highest Blood Sugars next
3. Maintain a 50:50 mix of Basal to Bolus Insulin

Evaluation
Adjustment of Insulin

Adjustment factors (for lows and highs)
1. Adjust Insulin in small steps at a time
2. Adjustment steps based on Insulin amount
  1. Insulin dose <10 units: Adjust by 1 unit
  2. Insulin dose 10-20 units: Adjust by 2 units
  3. Insulin dose >20 units: Adjust by 10% Insulin dose
3. Adjustment steps based on diabetes type
  1. Type I Diabetes Mellitus: 1-2 units change
  2. Type II Diabetes Mellitus: 2-4 units change
Correction protocol for Hypoglycemia
1. General measures to consider
  1. Increase Carbohydrate preceeding low
    1. Carbohydrate at prior meal or
    2. Snack or
    3. Pre-exercise Carbohydrate
  2. Adjust Exercise timing during the day
2. Basal insulin (e.g. Lantus) adjustment
  1. Blood Glucose low in AM
    1. Decrease Basal insulin (Lantus)
3. Rapid acting Insulin (e.g. Lispro) adjustment
  1. Blood Glucose low before lunch
    1. Decrease rapid Insulin (Lispro) at breakfast
  2. Blood Glucose low before dinner
    1. Decrease rapid Insulin (Lispro) at lunch
  3. Blood Glucose low before bedtime
    1. Decrease rapid Insulin (Lispro) at dinner
Correction protocol for Hyperglycemia
1. General measures to consider
  1. Decrease Carbohydrate preceeding high
    1. Carbohydrate at prior meal or
    2. Stop or decrease snack
  2. Increase Exercise prior to meal
2. Adjust Insulin based on Carbohydrate Count
  1. See Insulin Adjustment with Carbohydrate Counting
  2. One Unit covers each 10-15 grams Carbohydrate
  3. Add 1-2 units for every 50 mg/dl Glucose >150
3. Indications to adjust Basal insulin (e.g. Glargine)
  1. All Blood Glucoses >200 mg/dl
    1. Increase Basal insulin by 0.1 units/kg
  2. All Blood Glucoses high (within 50 mg/dl)
    1. Increase Basal insulin per adjustment above
  3. Pre-supper Blood Glucose high
    1. Adjust Basal insulin per adjustment above
  4. Fasting (AM) Blood Glucose high
    1. Perform 3 am Blood Sugar checks
    2. Critical to distinguish 3 AM low BG from high BG
      1. Dawn Phenomena (relative Insulin deficiency)
        Increase Basal insulin by adjustment above
      2. Somogyi Phenomena (Rebound Hyperglycemia)
        Decrease Basal insulin by adjustment above
4. Indications to adjust Bolus Insulin (e.g. Lispro)
  1. Two hour post-prandial >40-60 mg/dl over premeal
    1. Increase rapid acting Insulin before meal
  2. Blood Glucose low before meal
    1. Decrease rapid Insulin before prior meal
Average Insulin doses after titrating from start
1. Type I Diabetes Mellitus: 0.7 units/kg
2. Type II Diabetes Mellitus: 1.2 units/kg

References

Smith (2018) Am Fam Physician 98(3): 154-62 [PubMed]