Now that I've had a CGM long enough to observe my blood sugar patterns following certain kinds of meals and certain kinds of exercise or activity levels, I've learned that many of the rules that have been given to me over the years about where my blood sugar should be at what times simply do not work. Or at least, they don't work in an absolute way. Or there are so many exceptions to them that it's not really a rule any more. Or I can't achieve them with the tools currently placed at my disposal. Or something. This is especially true during pregnancy.
The "rules" I'm referring to are threefold:
The first is the rule about waking up with my blood sugar at 60-90. My "fasting" glucose. I put "fasting" in quotes because do you have any idea how often I have to eat during the night to bring my blood sugar up from a low? I have tried to explain to doctors that sometimes my "fasting" glucose is more of a reflection of the blood sugar drama of the night before, and may have as much to do with a correction bolus given at 3:00 in the morning following a midnight snack as it does with the accuracy of my basal rates. And do they know how weird my basal rates get during the night, in an attempt to prevent the midnight low, and how hard it is to get that right in the first place? Furthermore, I spend a good percentage of daytime hours at or below fasting level when I'm pregnant, because I limit my carbohydrate intake to avoid blood sugar swings and because I tend to err on the side of low rather than high. That means that if I'm at 130 mg/dL all night because I can't otherwise figure out how to keep my blood sugar from dipping too low while I'm asleep, baby still gets his fasting blood sugar time and I get a good night's sleep. I assume that the 60-90 mg/dL number comes from non-diabetic women, which I am not, and which I have not been for 23 years. So I am henceforth excusing myself from following this rule.
The second is the rule about postprandial targets (one hour after a meal aim for 130 mg/dL, two hours after a meal aim for 120 mg/dL). During my first pregnancy, I tested my blood sugar 12 times a day in order to monitor all these values, and by the middle of the second trimester, I had determined that a one-hour postprandial of 130 mg/dL was impossible unless I wanted to be at 75 mg/dL and falling two hours later. Which I didn't want to be. So the way I left it is that I would shoot for below 130 two hours later, and I would just eat less frequently and fewer carbohydrates to avoid the BG spikes altogether. However, this has still left me with so many low blood sugars that my endocrinologist didn't like to let me manage my own BGs during pregnancy, I could have drowned in a bathtub when I decided to clean the remains of my thrown up dinner off my skin while my blood sugar was somewhere below 30 mg/dL, and I one time drew blood scratching my husband's hand when he tried to force-feed me Gatorade during a nighttime low BG episode. So I haven't worked out what my new 2-hour postprandial target will be, but I have a feeling it's going to have a lot more to do with where my BG started when I began the meal and how the curve on my sensor screen looks or should look. Otherwise these numbers - which are also probably based on blood sugars for non-diabetic women, a fact which has not been true about me for 23 years - haunt my imagination every time I go to adjust my basal rates or bolus ratios. I've also sometimes wondered whether synthetic insulin works differently enough in a diabetic's body that taking postprandial targets for women who produce insulin naturally simply places an unfair burden on a diabetic using the synthetic stuff.
The third rule is about bolus insulin/basal insulin percentages: that you're supposed to be giving 50% of your insulin by basal rate and 50% by bolus. I mess with my basal rates too often: during and following hard exercise, following a big meal, during sedentary periods on Sundays and travel days and sick days and all the rest. I use a combination of temporary basals and square correction boluses for this, and the numbers are just bound to work out incorrectly when I look at the percentages on my pump. I suppose I could use more temporary basals instead of square correction boluses to fix this problem and increase the percentage of basal rate insulin that it appears I am delivering, but somehow it feels easier to say I need to add 2-3 units over the next 2 hours than to calculate percentages to increase my basal rate (what is it again?). So I am going to do my best to not worry about this one anymore, either.
The only real rule I follow is that I'd like my A1C to be below 7.0 apart from pregnancy, and below 6.5 during it. I think that's manageable, and it leaves me a lot more room to experiment and try things out for a few months, rather than a few days. I'm not sure I should be held to non-pregnancy blood sugar rules on a day-to-day basis, as long as my A1C shows that I'm averaging out somewhere close to normal. Somehow I've been able to have 4 healthy babies and I haven't ever been able to follow the rules precisely. So I'm at least doing enough right to make it work out, right?
But I am looking for a new set of rules. Have you found any blood sugar management rules that just don't work for you? Managing my blood sugars without rules is a bit of a trial. Suggestions you've heard from your care providers, or that you've discovered on your own by tweaking your pump settings and observing CGM trends, are welcome!