Around 1:30am, my wife discovered her blood sugar was 14.0 mmol/L (230 mg/dL). This is very high for her. Since adopting a low-carbohydrate diet a bad spike might be 9.0 mmol/L (162mg/dL).
Even stranger, before bed, she had taken twice her regular dose of long-acting insulin. She had taken twice the dose because her blood sugar has been riding high for two days. She’d been correcting these high blood sugars three times a day with a time-tested calculation of fast-acting insulin.
It all started on Sunday when we went to a fall fair in a neighboring small town. No, she didn’t eat any cotton candy or ice cream. With ketogenic poise she was quite content with a vegetable/chicken salad for lunch.
So what was causing the high blood sugars?
The weather has gone from frosty mornings on Friday back to hot and humid weather on Sunday. The “fall” fair felt more like a “summer” fair. So we assumed the blood sugar spikes were caused by the crazy weather. Every time there are drastic temperature changes Nicole’s insulin needs go up for a while.
But by this morning we started to suspect something else was up. It seemed like her long-acting insulin wasn’t working at all. She was just relying on a shot of Humalog every five hours to correct the the perpetual rise.
“When did you say you changed that vial of long-acting?” I asked at 6am this morning.
“Saturday,” she said.
“On Sunday, was the long-acting bagged with a cooler pack?” I asked.
“No,” she said.
Bingo! As Dr. Bernstein warns in his book Diabetes Solution:”Vials [of insulin] in current use may be kept at room temperature for convenience, but Lantus, Levemir, and Apidra (glulisine) are best stored in the refrigerator.”
For about four hours on Sunday Nicole’s vial of Levemir had been in a black backpack under the noon sun. Realizing this, we tossed the vial and punctured a new one. Even though Nicole had already taken her 6am dose of (spoiled) Levemir, she did it again with the fresh vial. Within three hours Nicole’s blood sugar had gone down to 4.0 mmol/L (72 mg/dL). A little too low, but a welcome change.
We had been quite disciplined about using a Frio Pack for storing insulin when traveling. Unfortunately, the habit fell away. After all, we live in Canada, where half the year we’re more worried about the insulin freezing.
Sadly, we needed a reminder like this to get us back to using proper storage methods when traveling. Even for trips involving less intense heat, a Frio Pack still seems like a good idea. Being out of the fridge may not completely ruin long-acting insulin (as it did here) but it probably degrades it’s effectiveness.