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Diabetes: symptoms, diagnosis, prevention and treatment

Many people have heard about type 2 diabetes, but its common precursor, prediabetes, doesn’t get as much attention. Prediabetes affects approximately 88 million adults in the US, and an estimated 84% of people with prediabetes don’t know they have it. According to the CDC, 15-30% of these individuals will develop type 2 diabetes within five years. In other words, more than 26 million people who currently have prediabetes could develop type 2 diabetes by 2026.

What is prediabetes? 

Prediabetes is a condition where a person’s blood sugar levels are higher than the normal range (less than 5.7%), but not high enough to be diagnosed as type 2 diabetes (6.5% or greater). This occurs when the body has trouble making insulin as well as using the insulin it does make effectively, and glucose starts to build up in the bloodstream instead of fueling the body’s cells. Insulin is the hormone that tells most of the cells in the body to take up glucose. In prediabetes, people typically have insulin resistance (when the body’s cells don’t respond to insulin as well) and don't make enough insulin. If no actions are taken, over time their ability to make insulin continues to be reduced. When this happens, prediabetes can progress to type 2 diabetes.

What are the symptoms of prediabetes? 

People typically do not experience symptoms of prediabetes, which partly explains why millions of people don’t know they have it. The American Diabetes Association reports that some people with prediabetes may develop symptoms of type 2 diabetes, though even people diagnosed with type 2 diabetes can show few or no symptoms at diagnosis.

frequent urination    blurry vision    Feeling Very Thirsty    Feeling Very Hungry    Slow Healing Cuts & Bruises    Numb, Tingling or Pain in Hands or Feet    Extreme Fatigue

How is prediabetes diagnosed? 

Prediabetes can be diagnosed through a number of tests:

1. An A1C test, formally called a glycated hemoglobin test or HbA1C test. This gives an estimate of a person’s average blood sugar levels from the past two or three months. It is measured by a blood sample taken in a healthcare office, hospital, or laboratory.

A1c Diabetes Results Chart  for Normal, Prediabetes & Diabetes

2. A fasting plasma glucose (FPG) test measures a person’s blood glucose level after a period of fasting (not eating) for eight hours. The test is a blood test typically done in the morning. If the test indicates prediabetes, a second test should be taken on a different day to confirm the diagnosis.

Fasting Plasma Glucose (FPG) test results chart  for Normal, Prediabetes & Diabetes

3. An oral glucose tolerance test (OGTT) measures the body's blood glucose level two hours after consuming a sugary drink. 

oral glucose tolerance test (OGTT) results chart  for Normal, Prediabetes & Diabetes

Who is at risk of developing prediabetes? 

People with obesity or excess weight (a BMI above 25 kg/m2) who are older are at a significantly greater risk for developing prediabetes, as well as people with a family history of type 2 diabetes. New guidelines encourage screening for diabetes and prediabetes starting at age 35 for people with overweight or obesity. Several other factors can influence prediabetes risk: 

  • Some racial and ethnic groups show higher rates of diabetes at younger ages and lower BMIs. 

  • A history of diabetes during pregnancy (called gestational diabetes) or giving birth to a baby weighing nine pounds or more.

  • Reduced physical activity – people who are physically active less than three times per week.

The CDC offers a fast, online screening test for evaluating someone’s risk for prediabetes. The ADA also offers a screening test to assess your risk for type 2 diabetes. These tests cannot confirm a prediabetes diagnosis, but they can indicate if you may be at higher risk for developing it. 

All adults over the age of 45 should be screened for type 2 diabetes (which also checks for prediabetes) at least every three years, regardless of other risk factors.

Why do people develop prediabetes? 

Prediabetes develops through a combination of factors that are still being investigated. Lifestyle factors, such as food, exercise, stress, and sleep play a role, as do aging, family history and even genetics. Prediabetes is not simply the result of high body weight – though obesity is one underlying cause of insulin resistance. Many individuals with excess weight may never develop prediabetes or type 2 diabetes, while some people with prediabetes never have excess weight. 

What can people with prediabetes do to avoid type 2 diabetes? 

The most important action is to focus on living a healthy lifestyle. This includes making healthy food choices, eating less and increasing physical activity; you can find resources on these lifestyle changes below. Regarding weight management, research shows losing 7% of your initial body weight (about 15 pounds for people who weigh 200 pounds) and keeping much of that weight off is critical to lowering your risk for type 2 diabetes. Sustained weight loss over time can be key to improving health and delaying or preventing type 2 diabetes.

If you or someone you know has been diagnosed with prediabetes, here are a few helpful resources:

  • In-person diabetes prevention programs: The CDC offers a year-long lifestyle change program through its National Diabetes Prevention Program (NDPP) at various locations throughout the US to help people adopt healthy habits and prevent or delay the progression to type 2 diabetes. 

  • Online diabetes prevention programs: Several digital diabetes prevention offerings now exist, providing online education and personal coaching. Some of these programs are recognized by the CDC, and insurance companies and employers may cover the cost of these programs.

  • Medication: There is no currently approved medicine for prediabetes. However, metformin, a first-line therapy for type 2 diabetes, may help delay the onset of type 2 diabetes in people with prediabetes. It is sometimes prescribed “off-label” by healthcare providers for treatment of prediabetes. GLP-1 receptor agonists have been approved for obesity and may help delay the onset of type 2 diabetes. 

Can prediabetes be “cured?” 

In the early stages of prediabetes (and type 2 diabetes), careful attention to food choices, activity, and weight loss can improve blood sugar levels, effectively “reversing” the condition and reducing the chances of developing type 2 diabetes. However, this isn’t possible for everyone – some people have underlying factors (such as family history and genetics) that put them at a greater risk of type 2 diabetes, meaning they will always need to pay attention to blood sugar levels and lifestyle choices.

Helpful Articles:

The Basics

Diagnosed with Prediabetes? Here’s How to Find Support Near You – Participating in a lifestyle change program could help lower the risk of developing type 2 diabetes.

It's Not Just Blood Sugar, High Blood Pressure Matters Too – An explanation of why this health measurement is particularly relevant for people with diabetes or prediabetes.

What’s Cholesterol and Why is it Important? – An overview of the different types of cholesterol and how to keep yourself at healthy levels of each.

Dr. Anne Peters’ Top Ten Actionable Tips – Some helpful tips for communicating and improving relationships with your healthcare professional.

Nutrition & Food

What to Eat with Diabetes – How can people with prediabetes or diabetes approach nutrition? What kinds of food can help you keep your blood sugar levels in range?

What to Eat with Diabetes or Prediabetes: ADA's New Nutrition Guidelines – More positivity around low-carb diets; importance of weight loss for type 2 diabetes and prediabetes; emphasis on eating non-starchy vegetables and minimizing sugar and refined grains; no one-size-fits-all approach.

Diabetes Food Tricks and What I Really Eat – How Adam Brown learned to make low-carb food tasty, doable, portable, and fun. Plus, cool new diabetes food experiments he tested.

How to Thrive in a Toxic Food Environment that Encourages Bad Choices – Adam Brown gives some tips on how to become, and stay, a healthy eater.

Physical Activity

Diabetes & Exercise Solutions – No Time, Too Expensive, Painful, Boring, Unmotivated – Adam Brown provides 21 strategies to overcome key barriers to exercising.

The Most Underrated Diabetes Exercise Strategy? – Adam explains the benefits of walking to help manage blood sugar levels. Small steps can make a BIG impact!

Weight Management Drugs

Diabetes Drug Ozempic Approved for Weight Loss – Wegovy, a once-weekly injectable medication (semaglutide), has been approved by the FDA to treat obesity and excess weight – conditions that can lead to type 2 diabetes and prediabetes. 

*Please note, this page is not a comprehensive list of all the available resources.