DCB Newsletter #4/26: DID YOU KNOW… that the menstrual cycle can affect diabetes management every month?

Dear DCB Community,

We often talk about diabetes management in terms of glucose levels, insulin dosing, carbohydrates, physical activity, sleep, stress and technology. But there is another factor that can influence glucose patterns and insulin needs for many women and people who menstruate, month after month: the menstrual cycle.

In the latest episode of loop&life, the DCB Diabetes Tech Talk, host Greta Ehlers speaks with Martina Rothenbühler, Scientific Program Manager at the Diabetes Center Berne , and Laura Burlando, who lives with type 1 diabetes, about a topic that is still too often overlooked in diabetes care, research and technology development: diabetes and the menstrual cycle.

“No one ever talked to me about it.”

One of the most powerful moments in the episode comes from Laura Burlando. Laura has lived with type 1 diabetes for 18 years. She has also had a menstrual cycle for almost the same amount of time. Yet, as she explains in the episode, she was not really aware of cyclical changes in her own diabetes management until she started researching the topic herself during her master’s thesis at the Diabetes Center Berne.

“And then suddenly a light went off in my head,” she says. “I started noticing certain patterns in my own diabetes management.”

When Greta asks whether this was something Laura had already realised in her personal life with diabetes, Laura answers:

“But no one ever talked to me about it.”

This sentence captures the problem very clearly. Many people living with diabetes are used to looking for explanations. Was it the meal? Stress? Sleep? Exercise? A wrong estimate? A device issue? But if the menstrual cycle is not discussed in routine diabetes care, many people are left to discover these patterns on their own, be it through tracking, trial and error, conversations with peers or through social media. That is a challenge that should not remain with the individual alone.

A recurring factor, but still a research gap

From a research perspective, this gap is striking. As Martina Rothenbühler explains in the episode, the team expected to find more evidence. After all, roughly half of people living with diabetes are women, and the menstrual cycle is not a rare or exceptional event. It is a recurring physiological process. Yet the scientific evidence is still limited.

Existing studies suggest that glucose levels and insulin needs may change across different phases of the menstrual cycle. For example, some data indicate a tendency towards lower glucose levels or more hypoglycaemia around the beginning of the cycle, and higher glucose levels or reduced insulin sensitivity in the luteal phase, shortly before the next period starts. But it is not that simple because patterns vary from person to person. They can also vary from one cycle to the next in the same person. Some may notice changes around ovulation. Others may experience changes before or during their period. Some may not see a clear pattern at all.

This variability matters and makes the topic harder to translate into general guidance and harder to implement in diabetes technology.

But at the same time, this also makes the topic even more relevant, because if diabetes care and technology aim to support real life, they need to account for real-life variability.

Diabetes technology is not yet built for this

The episode also raises an important technology question. Current diabetes technology has become increasingly sophisticated. Many people now use CGMs, insulin pumps and automated insulin delivery systems. These tools can reduce burden and improve glucose management for many users. Still, there are limitations: current AID systems are not designed to meaningfully adapt insulin delivery based on menstrual cycle-related hormonal changes.

For people who do notice cycle-related patterns, this can mean manual work. They may create different pump profiles, adjust insulin settings, track their cycle in a separate app, or try to interpret recurring changes themselves.

Laura describes how research helped her better understand her own patterns and create pump profiles depending on her menstrual phase. But she also points out that it is not the same every month. Even with a relatively regular cycle, the diabetes impact can still vary and this is exactly where better evidence is needed: to understand possible patterns, differences and influencing factors more clearly.

The TIMES study: DCB’s contribution to closing the gap

At the Diabetes Center Berne, this question is not only being discussed, but also being researched.

The ongoing TIMES study aims to gain a better understanding of how insulin sensitivity changes over the course of the menstrual cycle in women with type 1 diabetes. The goal is to identify patterns in insulin requirements and glucose levels, with the hope of supporting more personalised diabetes care in the future.

The study is multinational and decentralised, meaning that participants contribute real-world data from their daily lives across several countries. This allows the study to capture more diverse and realistic patterns than a single-site study could. It collects data from automated insulin delivery systems, including glucose levels, insulin doses and carbohydrate intake. This is complemented by information entered by participants themselves, such as menstrual cycle data, symptoms and lifestyle factors.

The study also looks at possible confounders, including physical activity, because the menstrual cycle is not the only factor that may influence insulin needs.

This approach was chosen because it reflects everyday life more closely than a highly controlled setting. Diabetes does not happen in isolation, it happens during work, sleep, exercise, stress, travel, hormonal changes and everything else that shapes daily life.

The TIMES study is designed to help generate better evidence from that reality.

Why lived experience matters

A key strength of this episode is that it brings research and lived experience together.

Laura’s perspective shows what it can feel like when an important part of diabetes management is not named or explained. Martina’s perspective shows why this topic is scientifically complex and why better evidence is needed.

Together, their conversation highlights an important point: lived experience can help reveal where research, care and technology are still missing something.

What should change?

There is no single answer, but several needs are clear, as the podcast episode highlights:

• People living with diabetes should receive better information about the possible connection between the menstrual cycle and glucose management.
• Healthcare professionals should feel better equipped to discuss this topic in routine care.
• Diabetes technology should become more responsive to physiological changes that are part of real life.
• Research should continue to generate evidence that reflects the diversity of individual experiences.

As Greta says in the episode, it should not depend on someone doing their own research to discover that there may be a connection between their menstrual cycle and diabetes management.

This topic deserves more attention: in research, in clinical care, in technology development and in everyday conversations with people living with diabetes.

Listen to the full episode

In this episode of loop&life, Greta Ehlers speaks with Martina Rothenbühler and Laura Burlando about diabetes, the menstrual cycle, lived experience, research gaps, technology limitations and the ongoing TIMES study at DCB.

Listen or watch the full episode here:

YouTube: https://youtu.be/Th1L-lN9nCs

Spotify: https://open.spotify.com/episode/0pXQeasczpCIAeNAGt9WIZ

Apple Podcasts: https://podcasts.apple.com/ch/podcast/diabetes-and-the-menstrual-cycle-what-we-know-what/id1885831147?i=1000773847130

Learn more about the TIMES study on the DCB website: https://www.dcberne.com/en/times-study/