Diabetes and Fibroids: A Complex Relationship

How Diabetes and Uterine Fibroids May Be Connected

Diabetes and fibroids do not have a single, direct cause-and-effect relationship, but they share overlapping hormonal and metabolic pathways that may influence both conditions.

Three core mechanisms appear to connect them:

Insulin resistance: When the body becomes resistant to insulin, the pancreas compensates by producing more. This excess insulin stimulates the production of Insulin-like Growth Factor-I (IGF-I), a growth-signaling protein that may promote fibroid cell activity.^[3] Higher insulin levels can also suppress Sex Hormone-Binding Globulin (SHBG), a protein that normally binds to estrogen in the bloodstream. Lower SHBG means more free estrogen circulates in the body – and estrogen is the primary fuel for fibroid growth.

Hormonal disruption: Chronically high blood sugar can affect the balance of reproductive hormones. Some research suggests elevated blood sugar may increase androgen (male hormone) levels, which in turn can disrupt estrogen balance and may contribute to irregular periods.^[1]

Chronic inflammation: Type 2 diabetes is associated with ongoing low-grade inflammation throughout the body. Inflammation is also believed to play a role in the environment that allows fibroids to develop and persist, though this connection is still being studied.^[2]

Can Fibroids Affect Blood Sugar Levels?

Fibroids do not directly raise blood sugar or interfere with insulin production. They are hormone-responsive benign growths made of muscle and fibrous tissue, not endocrine cells.

The conditions that drive fibroid growth – especially insulin resistance and elevated estrogen – are often the same conditions that make blood sugar harder to control.

There is also an indirect effect worth noting. Large or multiple fibroids can cause heavy menstrual bleeding and may lead to iron-deficiency anemia.^[2] Chronic fatigue from anemia can make it significantly harder to maintain the habits that support blood sugar management – regular exercise, consistent eating patterns, and adequate rest. In this way, unmanaged fibroid symptoms can create additional challenges for women already navigating diabetes.

Fibroid Symptoms Women with Diabetes May Overlook

Diabetes and uterine fibroids share several symptoms, which can make it easy to attribute fibroid signs to blood sugar issues alone.

Symptoms that overlap with diabetes and may actually point to fibroids include:

• Heavy, prolonged, or irregular menstrual periods
• Pelvic pain or pressure
• Fatigue and weakness, which can stem from fibroid-related anemia rather than blood sugar alone
• Frequent urination
• Bloating or a feeling of fullness in the lower abdomen

A conversation with your doctor about the full picture of your symptoms – and a pelvic ultrasound if fibroids are suspected – can help clarify what is driving each one. A diagnosis of diabetes does not rule out fibroids.

What the Latest Research Says About Diabetes Treatment and Fibroids

A 2024 prospective study published in The Journal of Clinical Endocrinology and Metabolism examined the relationship between diabetes biomarkers and new fibroid diagnoses in more than 2,500 midlife women over nearly two decades.^[3]

The findings were notable. Women with diabetes were associated with a 28% lower incidence of new fibroid diagnoses compared to women without diabetes. Among those treated specifically with metformin, the association was stronger – roughly a 51% lower incidence of self-reported fibroid diagnoses compared to those without diabetes.^[3]

Researchers noted important limitations. The study relied on self-reported fibroid diagnoses, included a relatively small subsample with diabetes, and the results carried wide confidence intervals. The researchers described the findings as preliminary, and the precise biological mechanism is not yet fully understood.

Taking metformin specifically to prevent or treat fibroids is not a recommended approach based on current evidence. That decision should always be made with a physician based on your full health picture.

What the research does suggest is that addressing insulin resistance – a cornerstone of diabetes management – may also have implications for fibroid risk in midlife women. A fibroid specialist can help you understand how your metabolic health and fibroid status relate to each other.