August 27, 2003
Daily Care
Question from Birmingham, Alabama, USA:
I am 34 years old, have had type 1 diabetes for three months now, and I am on Lantus at night with NovoLog at each meal. My doctor started me out at 10 units of Lantus with 2 units of NovoLog at each meal, but my blood sugars were way too high (250-300+ mg/dl [13.9-16.7 mmol/L] ) both two hours after eating and right before meals. He then increased my dosage to 12 units of Lantus with 5 units of NovoLog. I have since increased my NovoLog 2-3 units on my own, and have blood sugar levels in the 120-220 mg/dl [6.7-12.2 mmol/L] range now. They are lower in the morning, and then increasingly higher throughout the day.
I would think I need more Lantus at night but, when I take 14 units of Lantus, I can drop 65-80 mg/dl [3.6-4.4 mmol/L] (with a snack) by morning. I do however require less NovoLog during the day. I have a two questions:
If my blood/sugar level is 150 mg/dl [8.3 mmol/L] when I take my Lantus (10:00 pm), what would be a good target for my before breakfast blood sugar?
Would you say my ratios are okay when I take 12 Units of Lantus and 24 Units of NovoLog a day? This certainly is not a 70/30 ratio that my doctor had planned on. Is there ever a danger of too much fast-acting insulin?
Answer:
It sounds like you and your doctor are not through adjusting the doses. For instance, it sounds like you may have to increase the lunch and supper doses of NovoLog. There is no law that says the doses have to be the same throughout the day. In fact, if you eat more food in the evening, it makes sense you may need more rapid-acting insulin to cover your meals. The Lantus (insulin glargine) is best adjusted to the fasting blood sugar.
JTL
[Editor’s comment: Typically, on basal/bolus program, such as yours, about half of the total daily dose is given as basal. As Dr Lane said, dosing is adjusted according to the fasting blood glucose level. A good target for this would be about 70-100 mg/dl [3.9-5.6 mmol/L]
The remainder is given as bolus insulin and is used dosed using an insulin:carbohydrate ratio. That way, you do not have to be rigid with meal planning. A ratio of 1 unit of NovoLog per 15 grams of carbohydrate would be a starting point for most people, with the dose titrated according to postprandial blood sugars.
Please set up a meeting with your diabetes team to discuss this. In addition, you might find Using Insulin By John Walsh, PA, CDE. and Ruth Roberts, MA very helpful as you learn to adjust your own insulin.
SS]
