What Are Metabolic Syndrome, Insulin Resistance, and Prediabetes?

Similar conditions that can lead to type 2 diabetes

Metabolic syndrome, insulin resistance, and prediabetes each independently increase the risk of type 2 diabetes. Although they have some similarities and a few overlapping features, each condition has its own diagnostic criteria and they rarely cause any symptoms.

If you have been diagnosed with metabolic syndrome, insulin resistance, or prediabetes, you can reduce your chance of developing diabetes with a combination of dietary modification, exercise, and/or medication.

And if you have been diagnosed with diabetes, you can substantially decrease the harmful effects of the disease with lifestyle changes and medical care.

Blood glucose can be measured with a blood test
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Definitions and Diagnostic Criteria

Metabolic syndrome, insulin resistance, prediabetes, and type 2 diabetes are all characterized by high blood glucose (sugar).

These conditions are harmful to your overall health, and the adverse effects increase over time. Each is identified based on common diagnostic screening tests, such as blood glucose levels.

These are the basic definitions:

  • Metabolic syndrome is a collection of conditions that adversely affect health and may lead to type 2 diabetes.
  • Insulin resistance is a condition in which your body does not respond properly to insulin, and it is believed to play a role in metabolic syndrome and prediabetes, as well as diabetes.
  • Prediabetes is often identified before type 2 diabetes develops. Both conditions are defined by elevated blood glucose levels and abnormal glycated hemoglobin (HbA1C) level, a value that reflects blood glucose levels over the past three months. 

You may fit the criteria for one or more of them.

  Metabolic syndrome Insulin resistance Prediabetes Type 2 diabetes
FPG 100 mg/dL or higher 100 to 125 mg/dL 100 to 125 mg/dL 126 mg/dL or higher
A1C     5.7% to 6.4% 6.5% or higher
OGTT     140 to 199 mg/dL 200 mg/dL or higher
Random glucose test       200 mg/dL or higher
Waist circumference Over 40 inches (men) or 35 inches (women)      
Triglycerides 150 mg/dL or higher      
HDL cholesterol Less than 40 mg/dL (men) or
50 mg/dL (women)
Blood pressure 130/85 mmHg or higher      
Milligrams per deciliter (mg/dL); Fasting plasma glucose (FPG); Oral glucose tolerance test (OGTT); High-density lipoprotein (HDL)

Symptoms and Complications

Generally, metabolic syndrome and insulin resistance don’t cause noticeable symptoms, but sometimes they can cause fatigue. Diabetes and prediabetes may cause frequent urination, a dry mouth, and increased thirst, as well as fatigue. 

While the symptoms of all of these conditions can be subtle, chronically high blood glucose slowly damages the body and leads to substantial health complications. 

Consequences of high blood glucose include:

  • Vision loss from diabetic retinopathy 
  • Pain and sensory loss due to diabetic neuropathy
  • Cold hands and feet as a result of peripheral vascular disease
  • Diminished wound healing 
  • Impaired immune system, often with a predisposition to frequent or severe infections
  • Heart disease and increased risk of heart attack
  • Cerebrovascular disease
  • An increased risk of stroke and dementia

The health issues that are part of metabolic syndrome often also accompany insulin resistance, prediabetes, and diabetes. Hypertension, altered lipid (fat and cholesterol) levels, being overweight, and having a large waist circumference can increase the risk of vascular disease, heart disease, stroke, dementia, and eye disease. 

Your likelihood of developing these complications increases if you have more of the contributing health risks. And the further your values (like blood pressure and triglyceride level) are from the optimal levels, the greater the harmful impact they are expected to have in your health.

Leaving these factors untreated increases their damaging effects—and getting adequate treatment for them can reduce or even reverse their impact.


You could be predisposed to metabolic syndrome, insulin resistance, prediabetes, and type two diabetes due to hereditary factors. These conditions all are associated with advancing age and they tend to run in families.

Lifestyle risk factors play a substantial role too. A sedentary lifestyle, being overweight, and eating a high sugar or high fat diet can all increase your chances of developing these conditions, especially if you are already prone to them due to your family history.

Type 1 diabetes is also characterized by high blood glucose, but it isn't associated with type 2 diabetes. Type 2 diabetes has a stronger genetic component and it usually begins during childhood.

Type 1 diabetes is an autoimmune disease which exact cause in unknown. Genetics, environmental facts, and exposure to certain viruses can increase the risk. Type 1 diabetes usually occurs in childhood, but can occur later too.

Unlike type 2 diabetes, type 1 diabetes is characterized by a low insulin level rather than insulin resistance. Type 1 diabetes is not preceded by prediabetes or metabolic syndrome.


If you have any of these conditions, you need to manage them so you can reduce the risk of their health effects. Treatment involves lifestyle modification, and often prescription medication as well. 

Sometimes high blood glucose can be reduced with adhering to a low glycemic diet that includes foods like vegetables and fruit and whole grains that don’t raise your blood glucose excessively.

A plant-based diet and Mediterranean style of eating can also reduce the risk.

There are many classes of medications that are used to lower blood glucose and reduce insulin resistance. Your needs should be individualized based on your current blood sugars, weight, age, and other health conditions. Discuss your options with your doctor.

If you have high blood pressure, your healthcare provider may recommend that you start exercising and that you begin a low-salt diet. If you smoke, ask them about a smoking cessation program.

Medications used for treating hypertension in people who have diabetes include angiotensin-converting enzyme inhibitors (ACE inhibitors) like Capoten (captopril) and angiotensin receptor blockers like Cozaar (losartan).

High triglyceride levels and low HDL can often be managed with exercise and dietary modification that includes reducing your intake of unhealthy fats like bacon or deep-fried food and also increasing your intake of healthy fats like nuts and avocados.

You can also reduce triglycerides by moving regularly and reducing intake of added sugars, like sweetened beverages and alcohol.

Medications used for managing lipid levels include statins like Pravachol (pravastatin).

And you may be able to lose weight and decrease your waist size with diet and exercise. Sometimes bariatric surgery is necessary to achieve weight loss.

All of these dietary changes can seem difficult to manage, especially if it is a major change from what you are used to. You may benefit by getting guidance from a registered dietitian. 


If you have been diagnosed with metabolic syndrome, insulin resistance, prediabetes, or diabetes, you can make healthy changes in your lifestyle to prevent the long term consequences of these conditions. Reducing your blood sugar is only a part of the treatment goals. Managing your weight, blood pressure, and lipid levels are also components of the comprehensive plan.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Serbis A, Giapros V, Galli-Tsinopoulou A, Siomou E. Metabolic syndrome in children and adolescents: Is there a universally accepted definition? Does it matter? Metab Syndr Relat Disord. 2020;18(10):462-470. doi:10.1089/met.2020.0076

  2. National Institute of Diabetes and Digestive and Kidney Diseases. Insulin resistance & prediabetes.

  3. ElSayed NA, Aleppo G, Aroda VR, et al. 2. Classification and diagnosis of diabetes: Standards of care in diabetes—2023. Diabetes Care. 2023;46(Suppl 1):S19-S40. doi:10.2337/dc23-S002

  4. MedlinePlus. Diabetes complications.

  5. Yau JW, Thor SM, Ramadas A. Nutritional strategies in prediabetes: A scoping review of recent evidence. Nutrients. 2020;12(10):E2990. doi:10.3390/nu12102990.

  6. Mirabelli M, Russo D, Brunetti A. The role of diet on insulin sensitivity. Nutrients. 2020;12(10):E3042. doi:10.3390/nu12103042

  7. ElSayed NA, Aleppo G, Aroda VR, et al. 10. Cardiovascular disease and risk management: Standards of care in diabetes—2023. Diabetes Care. 2023;46(Suppl 1):S158-S190. doi:10.2337/dc23-S010

By Heidi Moawad, MD
Heidi Moawad is a neurologist and expert in the field of brain health and neurological disorders. Dr. Moawad regularly writes and edits health and career content for medical books and publications.