“I am frequently waking up low in the morning which is really difficult,” said a new coaching client from Illinois. Lindsay Gopin is a mother of three and has had type-1 diabetes for 27 years.
Upon having Lindsay log her insulin doses and blood sugars, the source of the lows became clear. On April 15, for example, she woke up to a blood sugar of 9.4mmol/L (170mg/dL) at 2:30am. She then gave herself 1.5 units of fast-acting Humalog. She had been instructed by her doctors that 1 unit of Humalog would lower her blood sugar 2.5mmol/L (45mg/dL). So 1.5 units should have brought her down to 5.6mmol/L (101mg/dL). Her target blood sugar is 5.5mmol/L (100mg/dL).
Instead, four hours later, she ended up at 3.2mmol/L (59mg/dL).
“For the situation, my correction factor was too high,” emailed Lindsay that day. “Maybe we should change my cheat sheet so one unit lowers me 50mg/dL.”
These midnight corrections prove an ideal testing ground to see how insulin drops your blood sugar. Unless you’re munching on popcorn at 3am, there’s no food in the system to elevate the results.
“I think Humalog is causing much more of a drop than 50mg/dL,” I emailed back. “Here’s the math for what happened last night: (170-59)/1.5 = 74.”
Instead of assuming one unit of Humalog would only lower her 2.5mmol/L (45mg/dL), some straight forward calculations show it actually lowers her about 4.6mmol/L (75mg/dL). The insulin had 40% more effect than expected. I updated her blood sugar correction cheat sheet with a ratio of 1u to 45mg/dL.
The next night, a 14.6mmol/L (263mg/dL) blood sugar visited Lindsay. The cheat sheet advised 2-1/4 units of Humalog.
“I was so tired of going low,” she wrote, “so I only took 2 units.”
In the morning her blood sugar was 6.3mmol/L (115mg/dL).
“Looks like I did need that 1/4 unit,” Lindsay wrote. “But the 1H to lower 75[mg/dL] works great! WOW! I have been using 1H to lower me 40[mg/dL] for 15 years! No wonder I am crashing all the time.”
In this second situation, two units lowered her 148mg/dL. Halve that and you get 74mg/dL. Exactly the same ratio as the night before.
I don’t tell clients how much insulin to take (because I don’t want to go to jail). I just have them run simple tests like this. They find out for themselves how much they need. While the effect insulin has on blood sugars does vary from person-to-person, I haven’t found it varies much day-to-day.
Sadly, many people with type-1 diabetes overdose every single day on the insulin they use to correct high blood sugars. This leads to a low blood sugar. Then, they typically overdose on the amount of sugar they need to raise their blood sugar. Now they’re high again and need another (over)dose of Humalog… By tracking and measuring the effect fast acting insulin has on your bloodstream you can get off this roller coaster.
Roller coasters are fun for a few hours. Maybe a day. But not a lifetime.
Thinking outside the type-1 matrix,
–John C. A. Manley
P.S. Another important point when correcting high blood sugars is revealed in this post: ’Twas the High Blood Sugar Before Christmas: The 5-Hour Humalog Rule
P.P.S. “Your coaching is beyond amazing!” wrote Lindsay Gopin this week. “Your knowledge, experience and confidence in how to manage diabetes is really reassuring.” If you’re interested in getting your HgbA1C below 5.5%, please contact me about one-on-one coaching.