When my son was diagnosed as type 1 18 months ago aged almost 16 and 6'2" tall, the hospital had some formula they used to calculate a starting dose for his insulin. He was started on the basal bolus regime though. Their formula was something like (can't remember exact figures) 0.7u units per kg of body weight per 24 hours. It then worked out something like 56u of insulin per 24 hours, so, they split it in half, gave half as the basal insulin (Lantus) at bedtime, then split the remaining 50% into 3 equal doses for pre-meal bolus injections (Novorapid) - would have been probably 7 units per meal as it doesn't divide exactly. That was just for a few days. They then quickly taught us about carb counting, so kept his basal at 28 units but we then counted carbs and calculated his insulin needs for meals as 1u per 10g of carbs. His largest carb meal would most days be his evening meal.
Of course, over the first few weeks, his levels came down, but were a bit erratic as we got the hang of things. They were most interested in his waking levels, and when we had a run of figures regularly above the recommended fasting level, his nurse upped his Lantus by a unit. After a week or two if things started creeping up again, she upped it again. This carried on until he got most readings within range. He did settle I think on 30 units of basal (Lantus) at night, then carb counting at mealtimes for his Novorapid.
Of course a few months in, he started having a few hypos. After a few in one week I rang his nurse, gave her a run down of his figures, so she then started reducing his Lantus by a unit at a time.
This, as you will learn, is how it goes on. Things change, for no apparent reason, so just as you think you have the hang of it and things are going well, something makes it all go belly up!
I assumed, from the way they calculated his starting doses, that as he is a big lad he would be on significantly more insulin than someone smaller. I have a friend with a T1 son who is 18 months younger, diagnosed as a 3 year old, and significantly smaller than my son, but he is on larger doses than my son.
So, in answer to your original question, I don't think there is anything like an 'average' dose, people's needs seem to vary drastically. They have to pick a figure from somewhere to start you on, and that's just the way my son's team did it. It's just finding what is working for you. It may take a little time to tweak things more satisfactorily.
My son is now on a right comibination of different insulins due to his non-compliance, but as his mother I feel the basal bolus worked so well, so as others have said, I would in your position ask if you could be changed. My son is currently on one mixed one in the mornings and I don't see things settling properly at all on that. It worked so much better on the Lantus/Novorapid regime and you could react to changes quickly.
Of course this is all about T1, and I appreciate your case is slightly different. Glad to hear you are getting the hang of injecting though, well done.
Tina
