Changing Insulin Needs: The Menstrual Cycle

This is a PSA for women with diabetes of child-bearing age:

Your monthly cycle WILL affect your blood sugar levels!

I spent 13 years blaming everything under the sun for unexpected high and low blood sugar levels. I blamed the food, carb count calculations, a 'bad' bottle of insulin, pump errors, infusion set issues-- but strangely enough, I never knew how much of an impact my monthly cycle had on blood sugar levels.

The blood sugar swings that I was experiencing from carbs and inconsistent corrections were blinding me from the other underlying issues. It wasn't until I started low carb and removed many of the above variables that I could plainly see the change in hormone levels.

I need a 30% increase in long-term basal insulin for the week leading up to my period, then an immediate 40% decrease on day 1 (or 10% lower than my 'normal'), then back up to my normal basal rate for the remainder of the month.

Although it's exhausting to be making these changes all the time, it's worth it to track your cycle and make the appropriate basal insulin changes to avoid both high and low blood sugar levels as a result of fluctuating hormones.

This is just one more step toward giving you the power to control diabetes - rather than the other way around. 

A recent article in Diabetes Daily details the cyclical changes in blood sugar levels like this:

"Studies have shown that insulin sensitivity decreases during the early luteal phase, leading to a higher likelihood of hyperglycemia during this phase of the cycle. This likely occurs due to the marked increase in progesterone, which is associated with insulin resistance. In contrast, the follicular phase is characterized by increased insulin sensitivity. Insulin sensitivity was associated with the increased FSH levels observed during the follicular phase."

As an example, when using an insulin pump, my personal basal rates are:

130% basal rate for days 21-28

90% basal for day 1

back to 100% basal for days 2-20

(Keep in mind that everyone is different and this is just my personal experience. This should not be considered or used as a medical advice.)

To read more about WHY these basal fluctuations occur, check out this article from Diabetes Daily which details more about why these changes occur. 

If you're looking for a tool to track your cycles and give you a heads up when you may be entering a change in hormone levels, check out Clue menstrual tracker app, available free on Google Play Store or ITunes App Store . (I have no financial affiliation with this app, but I use it myself and like it.) 

Now that you know, track your cycle to see the differences in your blood sugar levels, and adjust your basal rate accordingly.