African man is sitting at the sofa at the home and taking blood from his finger due to diabetes. The daily life of a man of African-American ethnicity person with a chronic illness who is using glucose tester.

You May Have Prediabetes and Not Know It  

Utpal Pajvani, MD, PhD

Utpal B. Pajvani

According to the CDC, about 96 million American adults—more than 1 in 3—have prediabetes. And more than 80% of people who have prediabetes do not know they have it. 

Prediabetes is a serious health condition: People who have prediabetes are at risk of developing type 2 diabetes, kidney problems, heart disease, and stroke.  

The good news: You can stop prediabetes from becoming diabetes. We spoke to Columbia diabetes expert Utpal Pajvani, MD, PhD, a physician and researcher, to find out how. 

What is prediabetes? 

Prediabetes means your blood sugar levels are higher than normal but not high enough to be diagnosed as type 2 diabetes. Yet. Some people stay in this blood sugar range for years before progressing to type 2 diabetes. And not every person with prediabetes will progress to type 2 diabetes.  

Researchers think prediabetes and diabetes are largely a matter of genetics, which influence risk of obesity as well as insulin production. People with identical body weight and adiposity (body fat) can have normal blood sugars or prediabetes and diabetes risk. The reason why remains an area of active research. 

That said, there are also environmental contributors to prediabetes. Mitigation measures include exercise and diet changes. Because we still do not know who will progress or why, a diagnosis of prediabetes is a sign to take steps to prevent the possibility. 

You want to stop prediabetes as quickly as you can. Diabetes is even more severe because it affects every major organ. 

What causes prediabetes? 

Prediabetes is typically caused by insulin resistance. Insulin is a hormone produced in specialized cells in the pancreas called beta cells. When we eat, intestinal cells absorb carbohydrates, which increases blood sugar. In response, insulin is released by pancreatic beta cells, which helps dispose of this sugar into our tissues, where it is used as fuel. When someone is insulin-resistant, insulin is still released but doesn't work as well.  

Insulin resistance is caused primarily by aging and being overweight. 

How do you know if you have prediabetes? 

You can have prediabetes for years without symptoms, but prediabetes can be diagnosed with blood tests. Ask your doctor if you should be tested.

Be aware of the things that can increase risk of prediabetes: 

  • Being overweight contributes to insulin resistance 
  • Having a parent, brother, or sister with type 2 diabetes means you are likely to have genetic contributors to insulin resistance or deficient beta cell response to insulin resistance 
  • Being physically active less than three times a week 
  • Having diabetes during pregnancy (gestational diabetes) 
  • Giving birth to a large baby (generally, weighing more than 9 pounds)
  • Having polycystic ovary syndrome (PCOS); women with PCOS often have insulin resistance, though the mechanisms are not fully understood 

Eating fewer processed foods and more fresh, whole foods can help lower blood sugar levels.

How to reverse prediabetes 

With a healthy fresh food diet, just a small amount of weight loss (5% to 7% of body weight), and an increase in physical activity (30 minutes per day) the risk of prediabetes becoming diabetes goes down. 

Doing these things is also a way to prevent prediabetes. But we know it’s easier said than done. If you need help losing weight and/or becoming more active, talk to your doctor. 

New prediabetes treatments 

Insulin resistance increases with age and body weight; only one of these is reversible (weight). Therefore, therapeutic approaches aim to reduce body weight, through diet and other lifestyle changes, augmented with pharmacologic and sometimes surgical treatments.   

An expanding pipeline of new drugs has shown remarkable efficacy at reducing body weight (some by on average 20%, which will be sufficient to stop prediabetes from progressing to diabetes).   

Tolerance to sugar gets worse as you age 

Aging is a known risk factor for insulin resistance. The risk for prediabetes and diabetes increases as you age. 

The one question all patients ask about prediabetes: Why me? 

The simple and somewhat general answer is genes, with contributions from environmental influence. But which genes and what specific environmental contributors are not precisely known. 

Things everyone should know about prediabetes 

Prediabetes is reversible with weight loss. New, safe medications to help people lose weight are available, and even more effective medications are coming. 

Often, but not always, prediabetes progresses to diabetes. The rate of this progression is quite variable. 



Utpal Bhagirath Pajvani, MD, PhD, is associate professor of medicine at Columbia University Vagelos College of Physicians and Surgeons. He is a physician-scientist who focuses on type 2 diabetes and related metabolic diseases.