Does endometriosis raise your risk of type 2 diabetes?

Should women with endometriosis be screened for blood sugar problems?

Yes. In a study of nearly 3 million people, endometriosis was linked to a 46% higher risk of developing type 2 diabetes (hazard ratio 1.46). The link was strongest in the women doctors usually consider low risk.

Endometriosis is a condition where tissue similar to the lining of the uterus grows outside the uterus. It causes pain, heavy periods, and fertility problems for millions of women. It is also an inflammatory condition, and inflammation is one of the ways the body’s handling of blood sugar goes wrong over time.

Earlier research mostly found no connection between endometriosis and type 2 diabetes. This new analysis suggests those studies may have missed the signal by treating endometriosis as one single condition instead of several different ones.

What the Data Show

Researchers built a cohort of 2,939,364 people assigned female at birth using the Utah Population Database, following them from 1996 to 2021. Over an average of 10.8 years of follow-up, 99,978 of them were diagnosed with endometriosis.

Compared with women who did not have endometriosis, those who did had a 46% higher risk of developing type 2 diabetes (adjusted hazard ratio 1.46). The range around that number was tight, so the true increase is very likely between 43% and 50% (95% CI 1.43 to 1.50).

The risk was not the same for everyone. It depended heavily on where the endometriosis tissue was found. When endometriosis appeared at “other sites,” meaning outside the usual pelvic locations, the risk climbed much higher. For endometriosis at a specified other site, the risk was about 167% higher, or roughly 2.7 times the risk (adjusted hazard ratio 2.67, very likely between 2.51 and 2.84). For an unspecified other site, it was about 147% higher (adjusted hazard ratio 2.47).

The pattern in the subgroups runs opposite to what most doctors would predict. Premenopausal women showed a stronger link than postmenopausal women, at about 55% higher risk (adjusted hazard ratio 1.55). Women with a BMI under 30, meaning those who were not in the obese range, showed a stronger link than women in higher BMI categories, at about 139% higher risk, or roughly 2.4 times (adjusted hazard ratio 2.39). The connection also held whether or not a woman had a history of gestational diabetes, the type of diabetes that shows up during pregnancy.

Dr. Kumar’s Take

The subgroup results are the reason this study matters clinically. The link was strongest in the groups that look lowest risk on paper, meaning premenopausal women and women with a BMI under 30. This data says those are the women who may most need a blood sugar check if they have endometriosis, particularly the kind found outside the pelvis.

That said, this is observational research, so it cannot prove endometriosis causes diabetes. Two problems stand out. The first is residual confounding, meaning some other factor the researchers could not measure may explain part of the link. The second is detection bias. Women with endometriosis see doctors far more often than women without it, so they get more blood tests, and more testing finds more diabetes. The authors flag both of these themselves.

I still think the direction of the finding is worth acting on, because the cost of checking a fasting glucose or an A1c is close to nothing and the cost of missing early diabetes for a decade is high.

How strong is the evidence?

The size of this cohort is its main strength. With nearly 3 million people and more than 10 years of average follow-up, the estimates are precise, which is why the ranges around each number are so narrow. Endometriosis was also treated as a time-varying exposure, meaning a woman counted as having it only after she was diagnosed, which avoids a common statistical error.

The weaknesses come from the data source. Diagnoses were pulled from medical billing codes, not from surgical confirmation in every case, and endometriosis is famously underdiagnosed. The models adjusted for birth year, birth state, race and ethnicity, age, and BMI at entry, but not for diet, exercise, or family history of diabetes. The population was drawn from Utah, so the results may not carry over cleanly to other groups.

Practical Takeaways

If you have endometriosis, ask your doctor for a fasting glucose or A1c test at your next visit, even if you are young, at a healthy weight, and have no family history of diabetes.
Tell your primary care doctor about your endometriosis diagnosis, including where the tissue was found, since a diagnosis handled by a gynecologist often never reaches the rest of your chart.
A higher risk is not a diagnosis, and the everyday steps that lower diabetes risk for everyone, meaning regular movement, sleep, and limiting refined carbohydrates, still apply here.

FAQs

Why would endometriosis affect blood sugar at all?

The researchers describe endometriosis as an inflammatory condition, and this study was built to test whether that inflammation shows up in long-term metabolic health. Chronic inflammation is one of the recognized pathways toward insulin resistance, where the body stops responding well to its own insulin. This study measured the association, not the biology behind it, so the mechanism remains a hypothesis rather than a proven chain of events. That is a reasonable question for future work to answer directly.

What does “other site” endometriosis mean?

Endometriosis is usually found on the ovaries, the fallopian tubes, or the lining of the pelvis. “Other site” refers to tissue found outside those typical locations, and in this study it carried the highest diabetes risk of any subtype. The researchers separated it into specified and unspecified other sites based on how the diagnosis was coded in the medical record. If you have endometriosis, your operative or pathology report should state where the tissue was found, and that detail is worth knowing.

Does having a period still put me at risk, or is this a menopause issue?

The link was stronger before menopause, not after. Premenopausal women with endometriosis had about a 55% higher risk of type 2 diabetes, which was higher than the figure for postmenopausal women. This runs against the usual assumption that metabolic risk mostly builds after menopause. It does not mean menopause protects you, only that the endometriosis signal in this data was clearest in younger women.

If I have a normal BMI, does that protect me?

Not according to this data. Women with a BMI under 30 showed a stronger link between endometriosis and type 2 diabetes than women with a higher BMI, at roughly 2.4 times the risk. One likely explanation is that in women with obesity, other well-known drivers of diabetes risk are already so strong that endometriosis adds relatively little on top. In a woman without those drivers, endometriosis stands out more clearly as a risk factor.

Bottom Line

In a cohort of nearly 3 million people followed for more than a decade, endometriosis was associated with a 46% higher risk of type 2 diabetes, rising to roughly 2.5 times the risk for endometriosis found outside the usual pelvic sites. The most useful part of this finding is who it points to: premenopausal women with a BMI under 30, the group least likely to be screened. This is observational data with real limits, including the possibility that closer medical follow-up alone explains part of the signal, but it is a strong argument for adding a simple blood sugar check to routine endometriosis care.

Read the full study