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Sunday, 15 May 2016

Basal Tune Up

One of the (many) reasons I love wearing an insulin pump is because it uses only short-acting insulin. Short acting insulin, because it wears off much faster, allows you to more closely mimic the functions of a type zero pancreas in ways that long-acting background insulin can only dream of.

Throughout the day, my insulin needs can fluctuate by a lot. At my most insulin sensitive, I am using less than half of the insulin that I use when I am least sensitive.

Trying to calculate how much insulin I need, hour by hour, is not easy. What works for me one week, doesn't work the next. I lost my rhythm a year ago, and it has taken me that whole year, and constant CGM use to find a basal pattern that puts my A1c within reach of my target.

My background insulin is another way for me to tell the story of my life, for anyone who knows how to read the numbers.

19.00 to 04.00 - 0.9
The night-time shift. It took me many many months to get this basal pattern right. This basal rate holds me steady during dinner, steady at bedtime when my body is still chasing some straggling carbs floating around, and keeps me level all throughout the night. It is one of my higher basal rates, showing the effects that inactivity while sleeping has on blood sugar levels. It can't account for any spikes I might see from nightmares, or lows caused by any extra activity the day before, but nothing can really, except an actual pancreas.

04.00 to 08.00 - 1.1
It seems a small rise - only .2, and some would wonder wether it is truly needed. At around 4am, my body starts to wake up - releasing a bunch of 'time to get up now' hormones. Hormones and diabetes are not friends. I employ this small amount of extra insulin at wake-up time to help enforce law and order in my blood sugar levels. You don't give diabetes any unsupervised play time at night - the dry-mouthed, over-tired consequences are not worth it.

08.00 to 15.00 - 0.8
 My job is mostly sedentary, accounting for a higher basal rate. When I previously worked at a video store on my feet all day, I had a lower rate. From 8am until 3pm, I am mostly sitting at my desk. . This rate is also slowly dropping, as my work place has recently supplied us with those fan-dangled sit-stand desks, allowing me more activity during the day.

15.00 to 19.00 - 0.4
 I aim to exercise at 4.30pm (when I get home from work) everyday.  I have a delayed blood sugar response to this, and the blood sugar drop that corresponds with the extra movement of my limbs happens from about 3pm the following day (22.5 hours after I do the exercise). From 3pm, my blood sugar levels drop sharply, and I require little (or no) insulin until I sit down for the night. I also do my housework and cook dinner during these hours. Its pretty amazing to see how simple little daily activities can affect blood sugar levels.

People associate the pump with freedom - it is. It also isn't. Every thing that is programmed into my pump assumes that I will follow the same pattern of living day in, day out. Theoretically, the pump allows me to get up at 6am to exercise one day, and 4pm the the next. Yes, I can do this and have no ill consequences whilst I exercise, but I also can't do this because of the patterns that the insulin follows. It creates a logistical nightmare the next day, when all of a sudden my insulin needs drop at 4.30am (when I have the most basal insulin, leaving me prone to an overnight hypo) instead of at 3pm (when I use the least basal insulin). 


  1. Really interesting seeing someone else's rates! I don't think 0.9 and 1.1 is a small jump, my own rates vary by 0.05 sometimes! Do you ever set temp rates when you exercise? Or do you just do it every day and program the pump accordingly with set rates?

    1. No, I never remember to set temp basal rates. My educator would like me to, but I have never been able to remember to do it. But the drop I experiance is from the exercise the day before, not the exercise that I do that day. I just take off my pump when I exercise & that seems to work well.