Diabetes and Menstruation - a bloody mess

In addition to the many things that can affect your blood sugars, we can also add the female menstrual cycle every month. This often makes blood sugar regulation extra challenging. Just a quick reminder: the menstrual cycle begins on the first day of menstruation and ends with the last day before the next menstruation. This cycle repeats every 21-35 days.

Hormones are responsible for the blood sugar mess during menstruation.

The menstrual cycle consists of two phases, the follicular and the luteal phase, and both have an impact on insulin sensitivity. There are a lot of hormones involved, but the sex hormones estrogen and progesterone are the two main culprits responsible for our monthly period.

At the start of your period, during the first phase, also called the follicular phase, is when you may be most insulin sensitive and notice lower blood sugars. As estrogen increases towards the end of this phase, you may notice your blood sugars start to rise.

The concentration of progesterone is much higher and estrogen slightly higher a few days before the start of your menstrual period (i.e. in the second or luteal phase), which can be noticeable through increased blood sugar levels.

The reduced insulin sensitivity impacts every person’s blood sugar differently. I personally notice higher blood sugar levels or a stronger insulin resistance about 3-5 days before the start of my  period.

Monthly cycle and diabetes connection is often underestimated

Have you and your HCP discussed managing your blood sugar during your cycle? Your healthcare team can work closely with you in helping to get better blood sugar control during this time. 

Relationship between menstruation and blood sugar fluctuations have been known for a long time

The connection between menstruation and blood sugar metabolism has been known for decades. Since the 1940s, when researcher H.I. Cramer shared his findings on the relationship between the monthly cycle and blood sugar fluctuations in the Canadian Medical Association Journal.

So why is there so little discussion and training on it? Shouldn't we be able to expect it as a standard of diabetes education and that it’s routinely considered during therapy adjustments?

There are almost 200 million women with diabetes in the world. Women with diabetes are also more often affected by polycystic ovarian syndrome (PCOS) than women without diabetes. These include, for example, irregular bleeding, period pain, a very strong and/or longer period, as well as skin problems.

Documentation of cycle helps to prepare

Luckily, menstruation patterns for most can be somewhat predictable each month. Nevertheless, it makes sense to track your cycle so that you are always well prepared.

I personally track all my blood sugar data ​​in the mySugr app, which I log during my cycle, with the appropriate day (see photo). By adding this additional detail I can explain a lot of my unusual blood sugar fluctuations much better, or I can immediately explain to my endocrinologist how one of the outliers in the blood sugar data came about. I also use the "Clue" cycle app, which, along with many other helpful features, predicts my next cycle, or the next menstrual period, fairly accurately and reliably. On a side note, Clue also published a nice article about diabetes and menstruation a while back.

Menstrual cycle and adjustment of diabetes therapy

Knowing your cycle is important, because it's the only way to adjust for the fluctuations in blood sugar. For example, I personally need more basal insulin in the week before my menstrual period and then let the basal rate run at 130% - 150% percent. Many people with diabetes on a pump have created an additional basal profile for this time, so that all they have to do is just switch to it at the appropriate moment.

Then, as soon as your period starts and hormone concentration decreases, less insulin is usually needed. Individualization is key and it can take some time to work out whta's best for you.

This is precisely why accurate documentation and support from your healthcare team are so important and helpful.

What are your experiences? Does your cycle affect your blood sugar levels? And what about therapy adjustments?

With this in mind, Power to the Period!