Doctors have suspected it for years, but now a new study has found evidence linking endometriosis to a higher risk of type 2 diabetes in young women.
The long-term study, published in Diabetologia, following data from nearly 3 million women over 25 years, has found that women with endometriosis have a 46 percent higher risk of developing type 2 diabetes, compared to women without the condition.
"There is a strong link between them. It just had not been established."Dr Rishma Dhillon Pai
Dr Pai, who was not involved in the study, is a Mumbai-based consultant gynaecologist at Hinduja and Lilavati Hospitals among others, as well as former president of the Federation of Gynaecological Societies of India.
"What makes this study particularly interesting is that they've kind of narrowed down to specifics even within endometriosis," she tells The Quint.
What the Study Found
First, a quick rundown of how the study was conducted.
The study analysed health records of nearly 3 million women in the Population Database of Utah state in the US between 1996 and 2021, including nearly 100,000 diagnosed with endometriosis.
Researchers found that diabetes risk varied across different forms of endometriosis, and that some forms of endometriosis carried a much stronger association with diabetes than others.
"This study is strong because it asks a more complex question instead of a simple one, like whether women who have been diagnosed with endometriosis have diabetes. It questions whether the risk of getting diabetes varies based on the subtype of the disease and metabolic features," says Dr Sakshi Goel, senior consultant – obstetrics & gynecology at Madhukar Rainbow Children's Hospital, New Delhi, who was not involved in the study.
The link was greatest among women with extra-pelvic endometriosis, meaning the disease is found outside the pelvis.
"Previous studies largely evaluated endometriosis as a single condition and generally reported little or no overall association with type 2 diabetes," said Fuzak Nunziato, the study's lead author.
She added:
“Our findings add to a growing understanding that endometriosis may affect more than reproductive health alone.”
The researchers believe chronic inflammation linked to endometriosis may affect metabolic health, suggesting broader long-term health implications.
However, more research is needed to better understand the biological mechanisms connecting the two conditions and whether earlier metabolic screening could improve outcomes for people with endometriosis.
Dr Pai says the study is particularly significant because this link has been looked into before. "It's not like it's come out of the blue, but this is a long-term study of 25 years that gives us some definite answers."
A High-Risk Group That Was Going Unnoticed
Experts explain that endometriosis is a prevalent disorder that is especially difficult to diagnose and treat. At the same time, there also seems to be an increasing incidence of patients diagnosed with endometriosis.
Dr Sakshi Goel tells The Quint, "Endometriosis is a multifactorial disease and considered a long-lasting inflammatory disorder, which potentially affects the entire body."
"Hormones and their effects, genetics, and the immune system also play important roles. That complexity is what makes endometriosis so difficult to fully understand, prevent, and treat—there are multiple factors interacting at once," adds Dr Pai.
Speaking to the possible reason for this strong correlation, experts have a few theories.
"The link with type 2 diabetes seems to be driven by the impact of inflammation on many organs because of its ability to alter tissue functions. The presence of chronic inflammation is able to change tissues in a way that makes them resistant to insulin and impairs glucose control abilities."Dr Sakshi Goel
Speaking to The Quint, Dr Tripti Raheja, director, obstetrics & gynaecology at the CK Birla Hospital (R), Delhi, says, "One possible pathway is through inflammation-related changes in insulin signalling, which can contribute to insulin resistance and, over time, increase the risk of type 2 diabetes."
Dr Pai goes on to say, "This is why patients with PCOS and endometriosis have a higher risk of developing type 2 diabetes at a relatively early age. So there is a strong connection between these conditions—it just hadn’t been clearly established until now."
The study has also identified a higher-risk group: women with a normal BMI, rather than those who are obese, as we would classically associate with diabetes.
"This is a very specific group of women whom we would otherwise consider low risk. We would typically focus only on their endometriosis and not look for diabetes risk," said Nunziato.
In other words, the association was strongest among women with a BMI below 30 and those without other obvious high-risk factors, such as a history of gestational diabetes. If this group has almost double the risk—about 46 percent higher—then screening them could help identify women we would otherwise miss, say experts.
'A Wake-Up Call'
"I think this is an important study because of its scale and because it moves the discussion around endometriosis beyond reproductive health," says Dr Raheja.
"Every gynecologist sees patients with endometriosis in their day-to-day practice. For years, we’ve often approached it primarily from a hormonal perspective—suppress the hormones and control the disease. But there are clearly many more dimensions to it. Endometriosis is a much broader disease with implications for a woman’s long-term health."Dr Rishma Dhillon Pai
Because endometriosis is so common, with an estimated 15-20 percent of young women affected, the study's findings has important implications.
It is not a disease of older women; it typically begins in adolescence or early adulthood and can affect women throughout their 20s and 30s. So, if women with severe extra-pelvic endometriosis are at higher risk of diabetes, that has potentially lifelong implications. "We would have definitely missed looking for diabetes in this group," says Dr Pai.
Moreover, historically, doctors have had a tendency to look at endometriosis through a narrow lens confined to reproductive health.
"We spend a lot of time treating their pain, performing surgery, and suppressing the disease, but we may not be paying enough attention to their overall metabolic health, long-term diabetes risk, and prevention. That could have a major impact on their quality of life," says Dr Pai.
"With any disease, the first step is awareness and knowledge; the second is prevention, wherever possible; and the third is early diagnosis. Those three things can fundamentally change the course of a disease. So these findings are really an eye-opener and a reason for us to be more alert."Dr Rishma Dhillon Pai
"It is critical to keep in mind that insulin resistance is capable of being asymptomatic. Thus, I would not expect that patients with endometriosis and insulin resistance display certain symptoms. From a clinical perspective, it is more useful to identify metabolic risk in a patient with regard to their medical history, examination, and laboratory analysis," adds Dr Goel.
Experts conclude that these new findings should be viewed as a signal for further investigation rather than a reason to conclude that every woman with endometriosis is destined to develop diabetes.
Dr Goel adds, "The key takeaway of the research is that women with endometriosis need to be looked after in a comprehensive way, in order not to provide them only with treatment oriented at pelvic health issues."
Dr Pai agrees, saying, "We often say that endometriosis requires lifelong management. It’s not simply one surgery or three months of medication, and then the problem is solved. If we don’t counsel patients with that long-term perspective, we may be doing them a great injustice."