Bolusing Early: A Case Study
A few weeks ago, pregnancy induced insulin resistance set in ferociously. I recall this process as happening more gradually during my first pregnancy, but then again, mother's memories are pretty spotty, so I can't be sure.
In seems like over the course of a week or so, I noticed a need to bolus at least 30 minutes before eating to avoid post-prandial spikes. In fact, bolusing 45 to 60 minutes in advance of a meal yielded even better blood glucose control. The biggest issue was just remembering to plan ahead so that the insulin would be working by the time I was ready to eat; that took about a week to fit into my routine.
I wore my continuous glucose monitor for about a week as the insulin resistance was getting stronger. This helped me adjust to the change and not worry that my blood sugar was going to drop too low during the interim between bolusing and eating. However, my trust in the CGMS only went so far as there is at least a 20 minute lag between real time and the results on the monitor. Therefore, I'd often test at the 35 to 40 minute mark to see if the meal bolus had even started to lower my blood sugar. Often times, it hadn't.
One morning at work, I tested my blood sugar at 10:00 a.m. It was 107 mg/dl. I'd planned to eat a medium sized banana with natural chunky peanut butter and a few ounces of coffee with creamer (one of my favorite "treats")! I bolused 6.5 units of insulin and planned to eat around 11:00 a.m. However, my day got busy and I ended up in someone's office having an impromptu meeting just before 11:00 a.m. By the time I returned to my desk and remembered that I'd bolused already for my snack, it was 11:30 a.m. Nearly 90 minutes had passed and I got that sudden panicky feeling that I was going to be very low. But... I didn't feel low. A quick finger stick confirmed that I was fine: 88 mg/dl. I was able to calmly enjoy my meal, confident that my blood sugar was behaving.
Another trick I learned during this experience was that I needed more insulin to cover meals. By the time I ate the banana, only 4 units of insulin were still active in my body. Therefore, I gave myself another 1.5 units as I started to eat. Because of insulin resistance, I figured that bolus wasn't going to "kick-in" right away and cause a hypo before the banana's glucose entered my system. An hour after eating, my blood sugar was 110 mg/dl and it stayed under 100 mg/dl for the next few hours.
Insulin timing is an interesting aspect of blood glucose control, and one that's easy to underestimate. However, in my experience it's one of the most important factors. It's much easier to make small adjustments than lower a high post-prandial blood sugar. If I can keep my blood sugar from spiking in the first place, blood sugar control becomes much simpler.