The Hormonal Link Between PCOS and Diabetes

Polycystic ovary syndrome (PCOS) is a hormonal condition that causes increased androgen hormones, which play a role in male traits. PCOS can cause symptoms such as facial hair growth, irregular or absent menstrual periods, acne, ovarian cysts, and problems with fertility.

PCOS is also associated with insulin resistance, in which the body does not use the blood sugar-regulating hormone insulin well. It also is linked to an increased risk of developing type 2 diabetes.

A 2017 study found that people with PCOS were four times likelier to develop diabetes than those in the control group who did not have PCOS. Researchers also found that diabetes is diagnosed earlier in people with PCOS (or about four years earlier).

Despite this increased risk, there are measures that can be taken to treat insulin resistance and lower the chance of developing diabetes.

Read on to learn more about how how PCOS is related to diabetes and what can be done to address it.

Close up of a woman pricking her finger to check her blood sugar.

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Overlap Between PCOS and Insulin Resistance

Most people with PCOS have or will develop some degree of insulin resistance. The exact number isn't known, but it's estimated that 65% to 70% of people with PCOS are insulin-resistant.

People of any size or weight with PCOS can be insulin-resistant, but it's more common in those who have more body fat than those who are lean.

A 2012 study showed that insulin resistance and hyperinsulinemia (excess insulin in the blood) were present in 70% to 80% of people with PCOS who had a body mass index (BMI) of more than 30. Between 20% and 25% of people with PCOS had a BMI of less than 25.

While insulin resistance is more common in those who have a higher BMI, a 2015 study suggests that increased abdominal fat may be more of an indicator of insulin resistance risk than BMI. A hip-to-waist ratio of 0.85 or higher increases the risk of insulin resistance, regardless of BMI.

What It Means

Insulin is a hormone secreted by the pancreas. It regulates blood glucose (sugar) levels by helping the body use glucose for energy. When blood glucose rises, such as when someone eats, insulin is released.

If the cells do not respond well to insulin, the body produces more insulin. This is called insulin resistance. High insulin levels can cause fat to accumulate around the abdomen. It can also prompt the ovaries to produce more testosterone (a type of androgen), which contributes to PCOS symptoms.

Symptoms of insulin resistance include:

  • Weight gain (especially around the waist) and difficulty losing weight
  • Acanthosis nigricans (darkening and thickening of the skin around the neck, armpits, belly, button, and other skin creases; skin often feels "velvety")
  • Skin tags (small "flaps" of skin)

A person can be insulin-resistant but still have normal blood sugar levels if their pancreas produces enough insulin to properly regulate their blood glucose. As insulin resistance continues, the pancreas often can't keep up with enough insulin production to effectively regulate blood sugar. This leads to an excess of both glucose and insulin in the blood.

How PCOS Increases Your Risk of Diabetes 

PCOS may not directly cause diabetes. A 2021 study found that while people with PCOS do have a higher incidence of diabetes, it may be an association caused by common risk factors rather than a direct cause and effect.

This said, people with PCOS do have an increased risk of developing type 2 diabetes, whether or not PCOS directly causes diabetes. A 2017 study suggests that this increased risk of type 2 diabetes is related to body fat levels and that lean people with PCOS do not have an increased risk of developing type 2 diabetes.

Still, lean people with PCOS can be insulin-resistant, and studies conflict on risks associated with PCOS for lean people. More research is needed on this subject.

How Insulin Resistance Progresses to Type 2 Diabetes

With type 2 diabetes, a person is able to produce insulin. How and how well insulin works to manage blood glucose is what determines the level of insulin resistance:

  • Functioning normally: The pancreas produces insulin as needed to help glucose enter cells in the muscle, fat, and liver to be used for energy.
  • Insulin resistance: The cells don't respond as well to the insulin, so the pancreas releases extra insulin to make up for the cells' weak response. If the pancreas can create and release enough insulin to compensate, blood sugar levels will remain in control.
  • Prediabetes: The cells are not responsive to insulin, and the pancreas cannot create enough insulin to keep blood sugar levels in check. Extra glucose remains in the blood and blood sugar is higher than normal, but not high enough for a diabetes diagnosis.
  • Type 2 diabetes: This usually occurs after prediabetes. The pancreas cannot keep up with insulin production needed to control blood sugar. Blood sugar levels are higher with diabetes than prediabetes, as are complications.

Essentially, these are stages on a continuum. One stage does not always progress into another, but without management, over time, people with PCOS can shift from insulin resistance to prediabetes to type 2 diabetes. The good news is, steps can be taken to reduce the chances of progression and even reverse prediabetes.

Possible Warning Signs

Insulin resistance, prediabetes, and even type 2 diabetes may have few or no obvious symptoms. But if you are experiencing any of these warning signs, check with your healthcare provider about testing your blood sugar levels to be sure:

  • Increased or unusual thirst
  • Frequent urination
  • A change in weight (gain or loss)
  • Extreme fatigue or lack of energy
  • Blurred vision
  • Frequent or recurring infections
  • Cuts and bruises that are slow to heal
  • Tingling or numbness in the hands or feet

PCOS, Type 1, and Gestational Diabetes

When diabetes is mentioned in the context of PCOS, it usually refers to type 2 diabetes — but type 1 diabetes and gestational diabetes can affect and be affected by PCOS as well.

PCOS and Type 1 Diabetes

Type 1 diabetes is believed to be an autoimmune response that causes the body to stop making insulin. People with type 1 diabetes have a higher risk of developing PCOS.

A 2016 systemic review and meta-analysis suggests that people who have ovaries and have type 1 diabetes should be screened for PCOS because of the increased risk of developing PCOS and PCOS traits.

PCOS and Gestational Diabetes

Gestational diabetes occurs during pregnancy in people who have never had diabetes. It usually goes away once the pregnancy is over, but it can increase the risk of developing type 2 diabetes later on.

A large-scale study in 2020 showed that people with PCOS have an increased risk of gestational diabetes. It also suggests that although the level of risk can vary based on other factors (such as body fat levels), PCOS is an independent risk factor for gestational diabetes.

Treatment Plan for PCOS and Diabetes

 PCOS can be managed with lifestyle changes and medication. In doing so, the risk for diabetes can be reduced.

Lifestyle Changes

The insulin resistance associated with PCOS can be managed through lifestyle changes, either on their own or in combination with medication, depending on the circumstances.

For people with PCOS who have high body fat, a 10% body weight reduction can improve symptoms of PCOS, including insulin resistance and blood sugar levels. This weight loss is recommended only for people who are medically overweight and should be undertaken in a healthy way. Consult your healthcare provider for guidelines on how to tailor a weight loss plan to you personally.

Ways to decrease insulin resistance/restore insulin sensitivity include:

  • Exercise: Cardiovascular and strength training exercises can improve your sensitivity to insulin.
  • Healthy diet: Most healthy diet plans include whole grains, lean proteins, healthy fats, and lots of non-starchy vegetables. A diet that helps combat inflammation, such as a Mediterranean-style diet may be beneficial.
  • Stress management: Learn ways to manage stress, such as breathing techniques, mindfulness practices, and yoga. Too much stress can increase cortisol levels, which can lead to insulin resistance.
  • Sleep: Get enough good quality sleep. Seven to nine hours a night is recommended for adults. It's a good idea to be checked for obstructive sleep apnea (in which breathing stops and starts during sleep). It's common among people with PCOS and can make symptoms worse.

Medication 

Lifestyle changes on their own may not be enough to combat PCOS symptoms and/or insulin resistance. This is particularly true if diabetes is present. Two medications are often used to treat PCOS:

Oral contraceptive pill:

  • Used to control androgen levels.
  • May not be appropriate treatment for people with metabolic disorders (such as insulin resistance and diabetes)

Metformin:

  • Developed as a treatment for type 2 diabetes, but is often prescribed to treat PCOS
  • Improves the effectiveness of insulin produced by the body

Both of these medications have benefits and risks depending on factors such as symptoms, age, and lifestyle. Your healthcare provider will take that into consideration before prescribing them.

Metformin is often the first medication offered for type 2 diabetes. If metformin and lifestyle habits are not enough to control blood sugar, a healthcare provider may prescribe other medication (such as insulin) as well.

Difficulty Losing Weight From PCOS 

While losing excess weight can help manage PCOS, the condition itself can make losing weight difficult. In addition to excess blood sugar, insulin resistance causes excess insulin in the bloodstream. Insulin tells the liver and muscles to store blood sugar.

Because of the high sugar and insulin levels, the liver and muscles can become "full". The liver then sends the excess blood sugar to fat cells, where it is stored as body fat, particularly around the waist. This "weight gain leads to more weight gain" cycle can feel difficult to break, but it is possible.

Some ways to approach weight loss that is difficult because of PCOS include:

  • Treating insulin resistance: Metformin may help with weight loss.
  • Making sure you have an appropriate caloric intake: How many calories you should consume per day should be tailored to you as an individual. Too many (and even too few) calories can hinder your weight loss efforts.
  • Talking to a registered dietitian: A dietitian knowledgeable about PCOS and insulin resistance can help you make a healthy meal plan that includes the right foods in the right amounts to lose weight.
  • Exercising: Exercise not only burns calories but also builds muscle, which helps fight insulin resistance.
  • Undergoing eight loss surgery: This may be appropriate for people at high risk for complications whose PCOS is not responding to typical treatments.

Summary

Insulin resistance is common in people with PCOS. Without management, insulin resistance can develop into prediabetes and then type 2 diabetes. The risk is higher for those who have high body fat, particularly around the waist.

With treatment for PCOS and insulin resistance, such as a healthy diet, exercise, and medication like metformin, PCOS symptoms can be controlled and the risk for diabetes can be reduced or delayed.

A Word From Verywell

While people with PCOS are at an increased risk for developing diabetes, it isn't an inevitability. Even if your blood sugar levels are normal, adopt healthy lifestyle habits such as eating healthy foods, getting plenty of exercise and quality sleep, and managing stress. The sooner you develop these good habits, the better the likely outcome.

Frequently Asked Questions

  • How does PCOS affect blood sugar?

    Insulin resistance is common with PCOS. This means that the body becomes less efficient at using insulin to manage blood sugar. This can lead to prediabetes and type 2 diabetes.

  • What are the worst foods to eat with PCOS and diabetes?

    You should avoid foods that are high in sugar and/or are highly processed.

  • How do you regulate insulin with PCOS?

    A healthy diet, exercise, quality sleep, stress management, and a 10% or more weight loss (in people who are medically overweight) can help with insulin resistance. Your doctor may also prescribe metformin.

  • Do people with PCOS and diabetes need to take metformin forever?

    Metformin is often taken long term for both PCOS and/or diabetes. If blood sugar is being managed in another way, it may be possible to discontinue metformin under the guidance of a healthcare provider. Talk to your provider before stopping metformin.

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