Turner Syndrome and Diabetes

Diabetes is a condition that affects a large percentage of individuals with Turner Syndrome (TS). It has received even more attention due to the pandemic, as there is now a growing focus on staying healthy to help strengthen our immune systems. Of concern is the growing number of people who have been or are at risk of being diagnosed with diabetes. This applies to both people within and outside the TS community.

Read on to learn more about the various types of diabetes (or diabetes mellitus), their diagnosis, and treatment options. Also learn more about an upcoming Turner Syndrome Foundation (TSF) event that can help you learn more.

Diabetes: An Overview

Diabetes mellitus, often referred to as diabetes, occurs when the body cannot produce adequate amounts of insulin or cells lose insulin sensitivity, meaning it becomes difficult for cells to respond to insulin and take up glucose. Insulin is a hormone made in the pancreas that helps to control the amount of glucose in the blood by allowing glucose to enter cells and be used for energy. Glucose is a simple sugar and a main source of energy for cells. Controlling blood glucose levels is important because too much glucose in the blood can result in damage to the heart, nerves, kidney, eyes, and/or blood vessels. There are different forms of diabetes including type 1, type 2, and gestational diabetes. Type 1 diabetes is typically genetic and occurs as a result of the body’s inability to produce enough insulin on its own. Type 2 diabetes is often associated with obesity and occurs when cells develop an insulin resistance and become less responsive to insulin. Gestational diabetes occurs during pregnancy as hormones reduce insulin sensitivity. The term prediabetes is sometimes used to refer to high blood glucose levels that are not high enough to be classified as diabetes, but impaired glucose tolerance and impaired fasting glucose are used more often in the medical field to describe this. 


Individuals with TS have an increased rate of developing these conditions. While they can be dangerous, elevated blood glucose levels are treatable, so it is important for individuals with TS to look out for symptoms, monitor blood glucose levels, follow a healthy diet, and get regular exercise.

What Is Glucose Intolerance?

The term glucose intolerance is used to describe a variety of conditions that cause hyperglycemia, which refers to elevated blood glucose levels. Hyperglycemia can be dangerous when untreated because it can cause heart, nerve, kidney, eye, and/or blood vessel damage.

Glucose intolerance can be caused by a decrease in insulin sensitivity or an increase in insulin resistance, meaning cells are less responsive to insulin. It can also be caused by the body being unable to produce an adequate amount of insulin. Glucose intolerance can be classified into prediabetes and diabetes mellitus.

Blood glucose levels for the different conditions described in this article are:

  • Normal: fasting 70-100 mg/dl; non-fasting <140 mg/dl
  • Prediabetes-impaired fasting glucose: fasting 100-125 mg/dL;
  • Prediabetes-impaired glucose tolerance: non-fasting 140-199 mg/dL; and
  • Diabetes mellitus: fasting >125 mg/dL; non-fasting >199 mg/dL.I


Prediabetes occurs when you have high blood glucose levels, but they are not high enough to be considered diabetes. This condition is often associated with obesity and is reversible through lifestyle changes. Prediabetes includes impaired glucose tolerance and/or impaired fasting glucose.

  • Impaired glucose tolerance: blood glucose levels are elevated two hours after the 75 g glucose tolerance test (OGTT) but not high enough to be classified as diabetes.
  • Impaired fasting glucose: blood glucose levels are high in the fasting state, but not high enough to be considered diabetes.

Often, people do not show symptoms with prediabetes, but if they do, they might include:

  • acanthosis nigricans–darkened skin in the creases like the neck and armpits;
  • skin tags; and
  • blurred or altered vision.

Prediabetes increases the risk of developing diabetes, heart disease, and stroke in the future. Thus, it is important to control prediabetes through lifestyle changes.

Diabetes Mellitus

Diabetes mellitus occurs when the body is unable to produce adequate amounts of insulin or when there is a decreased sensitivity to insulin. Diabetes mellitus includes Type I, Type II, and gestational diabetes

Type 1 Diabetes

Type 2 Diabetes

Gestational Diabetes

Type 1 diabetes can be genetic or the result of environmental factors. It occurs when the pancreas is unable to produce adequate amounts of insulin to maintain healthy blood glucose levels. While treatable, this condition is chronic (i.e., non-curable).

Type 2 diabetes can be also be genetic or caused by other factors such as age or weight. Positive family history of type 2 diabetes is also a risk factor. It is associated with excess body fat. It occurs because of a decrease in insulin sensitivity. When insulin sensitivity is impaired, the insulin-sensitive cells can not take up glucose from the blood into the cell. Eventually, this results in high blood glucose levels. Additionally, similar to type I diabetes, it is also a chronic but treatable condition.

Gestational Diabetes occurs as a result of the hormones produced during pregnancy, which reduce insulin sensitivity or increase insulin resistance. However, this type of diabetes is often reversible, with insulin sensitivity going back to normal after a baby is delivered.


Symptoms of diabetes mellitus can vary, and different forms of diabetes mellitus may have different symptoms. General symptoms for all types include:

  • fatigue,
  • excessive thirst,
  • increased hunger,
  • unexplained weight loss,
  • blurry vision,
  • increased infections,
  • dry skin,
  • numbness in hands and feet,
  • sores and slow healing.

Some typical symptoms of type 1 diabetes, in addition to the symptoms listed above, include:

  • nausea,
  • vomiting, and
  • stomach pain.

When it comes to type 2 and gestational diabetes, symptoms are often undetected by patients.

Testing for Glucose Intolerance

There are a variety of tests an endocrinologist can perform to diagnose various types of glucose intolerance. Common tests include:

  • Fasting blood glucose test–a blood sample is taken after a night of fasting (8-12 hours) to determine blood glucose levels. A fasting blood glucose level of 100 mg/dL to 125 mg/dL is classified as impaired fasting glucose. A fasting blood sugar level of 126 mg/dL or higher is classified as diabetes mellitus.
  • Oral Glucose Tolerance Test (OGTT)–requires fasting for about 8-12 hours prior to the test. The patient then drinks a 75 g glucose drink and, after two hours, a blood glucose level is checked. For this test, a blood sugar level of 140 mg/dL to 199 mg/dL is classified as impaired glucose tolerance. A blood sugar level of 200 mg/dL or greater is classified as diabetes mellitus.
  • Postprandial glucose test: When a blood sugar level being tested is post-prandial, this means that the blood sugar levels are being tested 2 hours after food. It is usually tested in patients with diabetes mellitus on regular follow-up since it is more convenient than OGTT.
  • HbA1C test–a blood test that provides the patient’s average blood glucose level over the previous three months. This test may require fasting. An HbA1C result of 5.7% to 6.4% is classified as pre-diabetes. An HbA1C result of 6.5% or greater is classified as diabetes mellitus.
  • Random blood glucose test–a blood sample is taken from you at any time, without fasting, to determine blood glucose levels. A random blood glucose level of 200 mg/dL or higher, along with symptoms, is classified as diabetes mellitus.
  • Gestational blood glucose level tests are usually done between 24 and 28 weeks of gestation.



Treatment plans for prediabetes involve lifestyle changes, such as:

  • following a balanced diet,
  • increasing exercise,
  • quitting smoking,
  • reducing alcohol consumption, and
  • losing weight

If lifestyle changes are not effective, antidiabetic medications can be incorporated to maintain healthy blood glucose levels and decrease the future risk of developing diabetes mellitus.

Diabetes Mellitus

Type 1 Diabetes

Type 2 Diabetes

Gestational Diabetes

For those living with type 1 diabetes, insulin is needed throughout the day, in the form of:

  • injections,
  • inhalers, or
  • pumps.

For those living with type 2 diabetes, treatment options are similar to those for prediabetes.

Lifestyle changes, such as weight loss; exercise; healthy, balanced eating; quitting smoking; and limiting alcohol intake can help people manage their Type II diabetes.

Type 2 diabetics often need anti-diabetic medications like Glucophage (metformin) or Amaryl (glimepiride) to help control blood glucose levels. Some patients might also need insulin.

Depending on the severity of the condition, treatment options for those with gestational diabetes include: 

  • dietary modifications,
  • insulin, and
  • anti-diabetic medications

Link Between TS and Diabetes Mellitus/Glucose Intolerance​

Individuals with TS have a significantly higher risk of developing glucose intolerance, with about 70% of adults with TS having abnormal glucose metabolism. TS has a defect directly linked to glucose intolerance. 

Girls with TS are at slightly higher risk of developing type 1 diabetes as they grow up. And women with TS are at a much higher risk of developing type 2 diabetes as adults. Women with TS are more likely to be overweight or obese, contributing to the prevalence.

Even though growth hormone therapy for TS is associated with reducing the body’s sensitivity to its insulin levels, it has not shown to increase one’s chance of being diagnosed with glucose intolerance or diabetes mellitus.

Because of these increased risks, if you have or know someone with TS, or are a physician who treats patients with TS, it is important that you look out for potential symptoms of glucose intolerance or diabetes mellitus. It is especially crucial that you monitor your or your patient’s blood glucose levels, especially if there is a family history of diabetes or other risk factors.



  • Glucose intolerance and diabetes are serious conditions that can lead to heart, nerve, eye, kidney, and/or blood vessel damage if untreated.
  • All conditions that fall under the umbrella terms of glucose intolerance and diabetes mellitus are treatable through lifestyle changes and/or medication.
  • If you are a person with TS, your risk of developing glucose intolerance or diabetes mellitus is increased. Thus, it is important to follow a healthy diet, exercise, and consult your medical professionals if you notice any symptoms.
  • If you want to learn more about diabetes, we highly recommend that you view the TSF WE Learn webinar, Living with Type 2 Diabetes. It will discuss topics such as what steps you can take to reduce the risk of acquiring diabetes, and if you do have it, how to prevent complications and enjoy your life. To learn more about the webinar, click here.

Written by Julianna Franca, volunteer TSF blog writer. Edited by Prabhat, TSF volunteer blog editor, and Susan Herman, TSF volunteer lead blog editor.




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©Turner Syndrome Foundation 2021.

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