As many as 30% to 40% of women who have polycystic ovary syndrome (PCOS) also have insulin resistance — a condition that leads to high glucose levels and the potential for pre-diabetes and type 2 diabetes. In fact, insulin resistance may actually be at the root of one's PCOS, playing a role in causing the condition in the first place, as well as exacerbating its symptoms. Insulin resistance requires management with lifestyle modifications or treatment with medication to prevent complications, so it's something every woman with PCOS should be screened for.

The Conditions

PCOS is a hormonal condition that can cause irregular menstrual cycles, fertility difficulties, excess male hormone levels, and small follicles on the ovaries.

The pancreas, a gland in the abdomen with a number of functions, produces insulin. Insulin is typically secreted in response to increased blood levels of glucose, a small sugar molecule. When we eat carbohydrates, the glucose molecules enter into our blood within about 15 minutes. Insulin allows cells throughout the body to take in the glucose, which is later used for energy.

When someone has insulin resistance, the body does not respond to insulin as efficiently or as quickly as it should, leading to high glucose levels in the blood, low energy, or both. With time, larger and larger amounts of insulin are required before glucose is taken into the body tissues. Eventually, the body begins to deal differently with sugar.

Consistently high levels of glucose in the blood can lead to pre-diabetes, and then, to diabetes.

The Connection

PCOS is recognized as a risk factor for developing diabetes. Despite the fact that the signs and symptoms of PCOS begin before the signs and symptoms of insulin resistance, it is believed that insulin resistance may play a role in causing PCOS, rather than the other way around. Elevated insulin levels may be a contributing factor to inflammation and other metabolic complications associated with PCOS. While the connection is known, the causes of the relationship between the two conditions are not completely clear.

Most importantly, insulin resistance does not affect everyone in exactly the same way, and some women with insulin resistance develop PCOS, while others do not. Some experts suggest that obesity-associated insulin resistance alters the function of the hypothalamus and the pituitary gland in the brain, increasing the production of androgenic hormones, which contribute to PCOS. Excessive production of androgenic hormones is an independent risk factor for female infertility and ovarian dysfunction, with or without PCOS.

While each condition is associated with depression, the risk of depression is much stronger when the two conditions occur together.

Similarly, insulin resistance and PCOS each contribute to infertility. The hormonal changes of PCOS interfere with proper implantation of the embryo, while insulin resistance can lead to miscarriage due to inadequate nutrition and support of the growing embryo.

When PCOS and insulin resistance are combined, infertility and early miscarriage can make it difficult to carry a baby to term. If you have insulin resistance or PCOS, you are also at risk of developing gestational diabetes during pregnancy.

Symptoms

Symptoms of insulin resistance are similar in women who have PCOS and those who don't. It is important for women with PCOS to be aware of these symptoms because of the strong correlation between the two conditions.

Changes in Appetite

Insulin is an appetite stimulant, which is perhaps why many women with PCOS report frequent cravings for sweets and other carbohydrate-rich foods. This leads to weight gain, which increases the risk of health problems such as cardiovascular disease, obesity, osteoarthritis, and diabetes.

Pre-Diabetes or Diabetes

Pre-diabetes increases the risk of type 2 diabetes and other metabolic conditions. During this stage, which can last as long as 10 to 12 years, the body is not optimally sensitive to insulin. This leads to high blood sugar levels for a prolonged time after eating. Symptoms include decreased energy, increased thirst, and frequent urination.

Diabetes can cause decreased energy, neuropathy, vision loss, and vascular disease.

Screening

It is recommended that women with PCOS be routinely screened for insulin resistance so that it can be identified early, allowing earlier initiation of treatment.

Tests used to screen for insulin resistance include:

Fasting Blood Glucose Test: You will be instructed to abstain from food and drinks for a specific amount of time before your blood is drawn to check your blood sugar level. If your level is elevated, your doctor may want you to take further tests to determine how your body processes sugar.
Glucose Tolerance Test: Your blood sugar level will be checked, and then you will be given a special drink containing sugar. Your blood sugar will then be measured at designated intervals after you have consumed the drink to see how long it takes for your cells to process the sugar. If your glucose levels remain elevated for longer than normal, this may indicate that you are becoming resistant to insulin.
Glycosylated Hemoglobin A1C: This is a blood test that measures your average glucose levels over the past three months.

A Word From Verywell

While there is no cure for diabetes, it can be managed with dietary modification and medication. A number of steps can be taken to identify insulin resistance before diabetes occurs. If you have PCOS, some healthy lifestyle habits can help prevent diabetes long before tests would be expected to show abnormalities.

Incorporating daily exercise into your routine has been associated with a reduced risk of diabetes. Eating a well-balanced diet, low in fats and sugars, and rich in whole grains, low-fat dairy products, fruits, and vegetables have also been shown to reduce the risk of diabetes. Dietary supplements recommended for women with PCOS may help as well; ask your doctor if they are right for you.