How Common is Glucose Intolerance?

Glucose intolerance is common, affecting roughly 8% of people globally.

What are signs and symptoms of Glucose Intolerance?

The signs and symptoms of glucose intolerance, which is the stage before full-blown diabetes, may include: - Frequent urination: People with glucose intolerance may experience an increased need to urinate, as the body tries to eliminate excess glucose through urine. - Excessive thirst: Due to the increased urination, individuals with glucose intolerance may feel constantly thirsty. - Repeated infections: Glucose intolerance can weaken the immune system, making individuals more susceptible to infections that may occur more frequently. - Nerve damage: Glucose intolerance can cause nerve damage, leading to symptoms such as tingling or numbness in the hands or feet. It is important to note that these symptoms may not be present in individuals with prediabetes, as they often do not show symptoms. Regular checkups are crucial, especially for those with a family history of diabetes or previous gestational diabetes, as these could be indicators of prediabetes. If prediabetes progresses to diabetes, the symptoms mentioned above may manifest.

What else can Glucose Intolerance be?

The doctor needs to rule out the following conditions when diagnosing Glucose Intolerance: - Type 1 diabetes mellitus - Type 2 diabetes mellitus - Insulin resistance

What kinds of test are needed for Glucose Intolerance?

The main tests needed for glucose intolerance are the fasting plasma glucose (FPG) test, the 75-gm glucose tolerance test (GTT), and the A1C test. The FPG test measures blood sugar levels after fasting overnight, the GTT measures blood sugar levels before and 2 hours after drinking a glucose drink, and the A1C test provides an average of blood glucose levels over the last two to three months. These tests are used to diagnose diabetes and determine the risk of developing complications.

How is Glucose Intolerance treated?

Glucose intolerance is treated through interventions such as changes in diet and exercise. These lifestyle changes aim to improve the body's responsiveness to insulin and the functioning of insulin-producing cells. Research has shown that adopting healthier habits can reduce the chance of glucose intolerance progressing to type 2 diabetes. Losing and keeping off 7% of initial body weight through moderate exercise, reducing calorie consumption, and consuming a diet rich in monounsaturated fats, nuts, berries, yogurt, high-fiber foods, and tea can decrease the risk. Additionally, the medication metformin has been shown to help prevent progression to diabetes, particularly in patients with impaired glucose tolerance and impaired fasting glucose.

Are there long term effects of Glucose Intolerance?

The prognosis for glucose intolerance varies depending on the individual and various factors. Not all cases of glucose intolerance progress to full diabetes, with only 5% to 10% evolving into diabetes each year. The conversion from glucose intolerance to diabetes can increase from 25% to 50% as the A1C level raises from 6.0% to 6.5%.

What type of doctor should I see for Glucose Intolerance?

You should see an endocrinologist for Glucose Intolerance.

Glucose Intolerance

What is Glucose Intolerance?

Type 2 diabetes is a disease that is becoming more common, affecting people in developed and developing countries. This increase is due to a rise in obesity and changes in lifestyle, leading to more people being diagnosed with diabetes. In 2010, approximately 21 million adults were diagnosed with diabetes. This number is predicted to skyrocket to about 86.6 million adults by 2050, an over four-fold increase from today’s figures.

Glucose intolerance (GI) is a condition that involves having higher than normal blood sugar levels, but not as high as someone with diabetes. It covers both prediabetes (which is a warning sign before diabetes develops) and diabetes. It involves conditions such as having a slightly high fasting blood sugar level (IFG) and having a moderately high blood sugar after eating (IGT), as well as actual diabetes. We will focus on IGT and IFG here. People with these conditions are at an increased risk of developing diabetes and heart diseases. The World Health Organization prefers the term ‘intermediate hyperglycemia’ instead of ‘pre-diabetes’ to avoid attaching a stigma related to diabetes. Also, it’s crucial to understand that not all cases progress to full diabetes, with only 5% to 10% (more so for IFG) evolving into diabetes each year.

The American Diabetes Association (ADA) notes that the risk of developing diabetes is ongoing and increases beyond the lower end of the range, while significantly rising at the upper end of the range based on three diagnostic tests: Fasting plasma glucose (a blood test after an overnight fasting), the 75-gm oral glucose tolerance test (a blood sugar test taken two hours after consuming a sweet drink), and the glycated hemoglobin (A1C) test (which measures average blood sugar level over the past two to three months).

What Causes Glucose Intolerance?

The exact cause of glucose intolerance, or difficulty processing sugar, is still not fully understood. It seems to involve a mix of hereditary and environmental influences interacting with unhealthy habits like lack of exercise and poor diet. Both a resistance to the hormone insulin, which helps control your blood sugar levels, and problems with insulin release play a key role in causing this health issue.

Risk Factors and Frequency for Glucose Intolerance

Between 2009 and 2012, a high percentage of adults in the United States had pre-diabetes. Specifically, around 37% of people over 20 years old and 51% of people over 65 years old. The American Diabetes Association reports that in 2015, 84.1 million American adults had pre-diabetes. People with impaired glucose tolerance(IGT) usually don’t have symptoms. The only noticeable change is a higher glucose level, which leads to a significant number of undiagnosed cases.

In 2010 globally, roughly 8% of people had glucose intolerance. Many people in the United States are also affected by this – around 57 million people had impaired fasting glucose (IFG), while 30 million had IGT. A study found that after 10 years, 14% of people with normal glucose tolerance (NGT) develop IFG, and 48% develop IGT. The shift from NGT to IGT is about four times higher than the shift from NGT to IFG. People over 65 years old have a higher chance of abnormal 2-hour value during a glucose tolerance test (GTT) than younger people.

According to a comprehensive review by Zhang and his colleagues, as the A1C level raises from 6.0% to 6.5% the 5-year occurrence of diabetes can increase from 25% to 50%. Additionally, the conversion from glucose intolerance to diabetes depends on various factors such as the characteristics of the population studied and the criteria used for diagnosis.

Signs and Symptoms of Glucose Intolerance

People who have prediabetes, the stage before full-blown diabetes, often don’t show symptoms. Regular checkups are vital since the family history of diabetes or any previous occurrence of gestational diabetes (diabetes during pregnancy) could hint at prediabetes. In case these individuals have developed diabetes, symptoms like frequent urination, excessive thirst, repeated infections, and nerve damage may manifest.

During regular health check-ups, the person’s height, weight, and Body Mass Index (BMI) should be noted. Prediabetic folks often exhibit metabolic syndrome, a cluster of conditions including high blood pressure, high blood sugar, and abnormal cholesterol levels. Hence, they might be at risk for ASCVD, a group of conditions causing heart diseases, and they might experience high blood pressure. Eyes should be checked to exclude any diabetes-related eye diseases (retinopathy), and all pulses should be examined to look out for peripheral arterial disease, a condition where the blood vessels outside your heart are blocked.

Testing for Glucose Intolerance

Diabetes often starts 4 to 7 years before you know you have it. Regular blood sugar checks can help identify if you’re at risk of developing complications due to diabetes. If you’re over 40, you should get checked every year. If you’re at higher risk of diabetes, you might need to get checked more often. Factors that could put you at higher risk include belonging to certain racial or ethnic groups, being overweight or obese, having a family member with diabetes, or having certain health conditions (like heart disease, high blood pressure, polycystic ovarian syndrome, or a condition called acanthosis nigricans which are dark patches on your skin).

Women who had diabetes during pregnancy (known as gestational diabetes) should get checked at least every three years for the rest of their life. Most people should start regular checks at age 45. If your results are normal, you should repeat the test every three years at least.

The main tests include fasting plasma glucose (FPG) and A1C. A third test, known as the 75-gm glucose tolerance test (GTT), is less often used because it can be inconsistent and requires you to prepare in advance.

The FPG test measures your blood sugar after you’ve fasted overnight (not eaten for at least 8 hours). If your FPG level is between 100 and 125 mg/dL, you might be at risk of developing diabetes. If your FPG is 126 mg/dL or higher, you could have diabetes.

The GTT measures your blood sugar level before and 2 hours after drinking a glucose drink. If your level is between 140 and 199 mg/dL two hours after the glucose drink, you might be at risk of developing diabetes. If it’s 200 mg/dL or higher, you could have diabetes.

The A1C test is convenient as it provides an average of your blood glucose over the last two to three months. If your A1C level is between 5.7% to 6.4%, you’re at an increased risk of diabetes. If your A1C level is 6.5% or higher, you could have diabetes.

If you don’t have any symptoms of diabetes but one of your tests suggests you might have it, your doctor will likely want you to repeat the test just to be sure.

The GTT test can be difficult and inconsistent, so it’s not used as often. The A1C test can be done at any time, regardless if you’ve eaten or not. But there can be issues with this test if you have certain health conditions or if you’re of non-Caucasian descent. Both tests, while different, are used to diagnose diabetes. But because the GTT test is complicated, FPG and A1C tests are usually the tests used most often.

Treatment Options for Glucose Intolerance

Glucose intolerance puts one at a heightened risk for diabetes and related complications, but intervention can help to slow or prevent this progression. Interventions such as changes in diet and exercise seem to be most beneficial for those with an impaired ability to regulate their glucose levels, whether or not they also have problems with fasting blood glucose levels.

Lifestyle changes aimed at improving the body’s responsiveness to insulin and the functioning of insulin-producing cells are a crucial part of managing glucose intolerance. Research has shown that adopting healthier habits can reduce the chance of glucose intolerance becoming type 2 diabetes. The goal should be to lose and keep off 7% of your initial body weight. This can be accomplished through moderate exercise, such as brisk walking for at least 150 minutes per week, ideally spread out over at least three days.

Reducing the amount of calories you consume is especially important for those at high risk of developing type 2 diabetes. The type of fat you eat matters more than the amount. Diets rich in monounsaturated fats, such as those found in olive oil and avocados, can help to prevent diabetes. Eating more nuts, berries, yogurt and high-fiber foods, as well as drinking tea, can also decrease your risk. On the other hand, consuming red meats and drinks sweetened with sugar appears to increase one’s risk of developing type 2 diabetes. Two recommended diet plans are the Mediterranean diet, which includes lots of fruits, vegetables, and healthy fats, and the DASH diet, which focuses on reducing sodium intake to lower blood pressure.

Metformin, a medication that reduces glucose production in the liver and aids in improving insulin sensitivity in the body, has been shown to help prevent progression to diabetes. It can be particularly beneficial in patients who have both impaired glucose tolerance and impaired fasting glucose. This medication could have an even greater benefit for people under 60 who have a significant amount of weight to lose (a BMI greater than 35), and in women who have had diabetes while pregnant. The effectiveness of other drugs in managing glucose intolerance is not yet universally accepted by all medical organizations.

Here are some common drugs and conditions that may impact blood sugar levels: