Adjusting Insulin Doses Everyone with diabetes, including you, will need to adjust your insulin doses at some time. There are several reasons why a person may need an insulin adjustment. These reasons include the following: you are in the honeymoon period you are having a growth spurt you are going through hormonal changes (especially during teenage years) you have changes in your activity level your are sick or under stress you are attending special events such as birthdays, holidays, and vacations Before you make any adjustments to your insulin doses it is important to know what your target blood glucose range is. Research has shown that keeping your blood glucose levels in a range closer to normal significantly improves your overall health, decreases your risk for developing diabetes related complications, and improves blood glucose control. A study performed by the DirectNet Study Group found that approximately 95% of children without diabetes have fasting blood glucose levels between 70-100 mg/dl and random blood glucose levels between 70-130 mg/dl. Therefore, the Children s Mercy Diabetes Center has developed our own blood glucose guidelines based on these findings. The Children s Mercy Hospital Diabetes Center Recommended Blood Glucose Target Ranges (mg/dl) Age Age 5 years or younger Age 6 years and older Suggested Blood Glucose Level 80-180 mg/dl 70-140 mg/dl The American Diabetes Association recommends different blood glucose target ranges than our recommendations. You can find the ADA recommendations at their website: www.diabetes.org. Once you know what your blood glucose target range is, you can start to look at your blood glucose patterns. The CMH diabetes team recommends looking at your blood glucose patterns for at least five days before any changes are made to your insulin doses. When looking at your blood glucose results it is important to look for blood glucose levels that are above or below your target range and also what time of day the pattern occurs. You also want to consider other things that can cause your blood glucose to increase or decrease.
What affects your blood glucose? What makes blood glucose increase? Foods or drinks with carbohydrates Stress Illness (cold, fever, flu, or other infection) What makes blood glucose decrease? Exercise Insulin Honeymoon phase The best way to remember your blood glucose results and variables that may affect the results is to keep written records using a logbook or computer management system. Before you start to make adjustments to your insulin doses it is important to know which type of insulin, basal or bolus, is working at the time you have hyperglycemia (high blood glucose level) or hypoglycemia (low blood glucose level). Basal (background or long-acting) insulin (Lantus or Levemir) keeps your blood glucose in target between meals, once your bolus insulin has worn off, and during the night. Bolus (rapid or meal-time) insulin (Humalog, Novolog, or Apidra) works to keep your blood glucose in target range 2-3 hours after eating a meal or snack with carbohydrate. Once you know what insulin is working during the time of day you have hyperglycemia or hypoglycemia adjustments can be made. At CMH we recommend that you adjust one insulin dose at a time. Once you make an adjustment you should wait at least five days to see if the adjustment worked before any further changes are made; however, if you are having frequent hypoglycemia, it is appropriate to make changes after 2 days. INSULIN ONSET PEAK EFFECTIVE DURATION Long Acting Lantus (glargine) Levemir (detemir) Rapid Acting Novolog (aspart) Humalog (lispro) Apidra (glulysine) 1 hour 1 hour None Flat 2-2½ hours 2 hours 2 hours 20-2 12 23 hours 3-3 3 DURATION 2 2 Which insulin should be adjusted? Blood glucose showing a high pattern Before breakfast or overnight Before lunch Before dinner Before bed Dose of insulin to increase Evening long-acting insulin Morning rapid-acting insulin Lunchtime rapid-acting insulin Dinnertime rapid-acting insulin
Which insulin should be adjusted? Blood glucose showing a low pattern Before breakfast or overnight Before lunch Before dinner Before bed Dose of insulin to decrease Evening long-acting insulin Morning rapid-acting insulin Lunchtime rapid-acting insulin Dinnertime rapid-acting insulin Adjusting your basal insulin: Basal insulin doses (Lantus and Levemir) are most often adjusted by about 10 percent of the current dose. A general rule to follow when adjusting the basal insulin dose is: Current basal insulin dose Adjust by 10 units or less ½ -1 unit 10-20 units 1-2 units 20-30 units 2 units More than 30 units 2-4 units After you adjust your basal insulin dose it is important to wait 5 days to evaluate the results before any further adjustments are made. However, if you are having frequent hypoglycemia, it is appropriate to make changes after 2 days. Adjusting your bolus insulin: Bolus insulin doses (Humalog, Novolog, Apidra) are adjusted based on your 2 hour post meal blood glucose result. The goal is to have your 2 hour post meal result change no more than 40 mg/dl from your pre-meal blood glucose reading. Also, by after your meal your blood glucose should be near your target blood glucose range. Current bolus insulin ratio Increase or decrease by 1 unit per 20 grams of carbohydrate or higher 3-5 grams at a time 1 unit per 20 grams of carbohydrate or less 2-3 grams at a time Like before, you want to wait at least 5 days to evaluate the changes before any additional changes are made. If your blood glucose is above target 2 hours after your meal you need more insulin to cover the carbohydrate, so your insulin to carbohydrate ratio needs to be decreased. For example: if you re using a ratio of 1 unit per 15 grams of carbohydrate the ratio should be decreased to 1 unit per 12 grams of carbohydrate. If your 2 hour post meal blood glucose reading decreases more than 40 mg/dl from your pre-meal blood glucose then you re taking too much insulin and need to increase your ratio.
For example: if you re using a ratio of 1 unit per 15 grams of carbohydrate the ratio should be increased to 1 unit per 17 grams of carbohydrate. Examples of basal and bolus adjustments Date Breakfast After Lunch After Dinner Night Lantus Meal Breakfast Lunch ratio Sun 103 5 Mon 69 Tue 57 Wed 68 Thu 61 Fri 94 Sat 56 Comments Pattern of hypoglycemia before breakfast. Decrease to 4 ½ units of Lantus. Date Breakfast After Lunch After Dinner Levemir Breakfast Lunch Dose Sun 176 221 21 D Mon 154 134 Tue 139 142 Wed 163 197 Thu 125 146 Fri 141 162 Sat 155 156 Insulin:carb ratio Pattern of hypoglycemia before breakfast. Increase to 23 units of Levemir. Date Breakfast After Lunch After Dinner Lantus Insulin:carb ratio - Breakfast Lunch Dose Humalog Sun 101 168 19 1:15 Mon 115 204 Tue 97 149 Wed 89 152 Thu 120 171 Fri 102 136 Sat 94 120
Pattern of blood glucose increasing 40 mg/dl or more after breakfast. A decrease to 1 unit of Humalog per 12 grams of carbohydrate would be appropriate. Date Breakfast After Lunch After Dinner Lantus Insulin:carb ratio - Breakfast Lunch Novolog Sun 124 80 10 1:15 Mon 137 74 Tue 118 63 Wed 99 82 Thu 104 59 Fri 96 54 Sat 108 62 Pattern of blood glucose decreasing 40mg/dl or more after lunch. An increase to 1 unit of Novolog per 18 grams of carbohydrate would be appropriate. References: http://www.rch.org.au/diabetesmanual/manual.cfm?doc_id=2979&doc. Retrieved August 31, 2007. Walsh, J. & Roberts, R. (4 th ed). (2006). Pumping insulin. San Diego: Torrey Pines Press. Wolpert, H. (2002). Smart pumping for people with diabetes. American Diabetes Association.