Elevated blood sugar levels that do not yet reach the threshold for a diabetes diagnosis pose a substantial public health issue in the United States. Allowing blood sugar levels to remain in this intermediate range substantially increases the risk of developing Type 2 Diabetes, heart disease, and stroke. Understanding the prevalence of this condition is important for recognizing the scale of the challenge facing the nation’s health system.
What Prediabetes Means
Prediabetes is a metabolic state defined by blood glucose levels that are abnormally high but remain below the diagnostic criteria for Type 2 Diabetes. This condition arises when cells become resistant to insulin, or when the pancreas cannot produce enough insulin to overcome this resistance. When this occurs, glucose builds up in the bloodstream, leading to chronic hyperglycemia that can cause damage over time.
The condition is officially diagnosed using specific laboratory thresholds for blood glucose measurements. For instance, a Fasting Plasma Glucose (FPG) test result between 100 and 125 milligrams per deciliter (mg/dL) indicates prediabetes. Similarly, the Hemoglobin A1C test must show an average blood sugar level between 5.7% and 6.4% to confirm the diagnosis.
Prediabetes is largely an asymptomatic condition, meaning most people experience no noticeable physical changes. This absence of warning signs is why the condition often goes undiagnosed for years, allowing metabolic issues to progress silently. In some cases, individuals may notice acanthosis nigricans—patches of dark, thickened skin, particularly around the neck or armpits—which is a physical manifestation of insulin resistance.
The Current Prevalence Statistic in the U.S.
According to the most recent data from the Centers for Disease Control and Prevention (CDC), approximately 38.0% of the adult U.S. population has prediabetes. This means that more than one in three American adults are currently living with blood sugar levels that put them at heightened risk for Type 2 Diabetes.
This percentage represents an estimated 97.6 million adults aged 18 years or older across the country. This scale highlights a major national health challenge. The prevalence tends to increase with age, with nearly half of all adults aged 65 years or older meeting the criteria for prediabetes.
Despite the high number of affected individuals, a significant portion remains unaware of their condition. Current estimates suggest that more than 8 in 10 adults with prediabetes do not know they have it. This lack of awareness means nearly 80 million people are missing the opportunity to intervene and reduce their future health risks. The diagnosis gap underscores the importance of routine screening and public health initiatives.
Testing and Diagnosis Protocols
Prevalence statistics are generated through standardized blood tests that measure different aspects of glucose metabolism. The three primary methods used for screening and diagnosis are the Hemoglobin A1C test, the Fasting Plasma Glucose (FPG) test, and the Oral Glucose Tolerance Test (OGTT). These tests offer different perspectives on how well a person manages sugar.
The A1C test, also known as the glycated hemoglobin test, is a simple blood draw that provides an average measure of blood glucose levels over the preceding two to three months. This measurement works by determining the percentage of hemoglobin that has sugar attached to it (glycation). Because red blood cells live for about three months, the A1C test is a reliable indicator of long-term blood sugar control and does not require the patient to fast beforehand.
The FPG test, by contrast, provides a snapshot of blood sugar at a single moment in time. This test requires the patient to fast for at least eight hours before the blood sample is taken, usually first thing in the morning. The resulting plasma glucose level measures the amount of sugar circulating in the blood after the fast.
The Oral Glucose Tolerance Test (OGTT) is typically a two-hour procedure that assesses the body’s ability to process a large load of sugar. After an initial fasting blood sample is taken, the patient drinks a standardized, high-glucose solution. A second blood sample is drawn two hours later to see how effectively the insulin response has cleared the glucose from the bloodstream. The OGTT is useful for identifying impaired glucose tolerance.
Preventing Progression to Type 2 Diabetes
A prediabetes diagnosis should be viewed as a clear opportunity for intervention, as progression to Type 2 Diabetes is not inevitable. The most effective strategy is an intensive behavioral lifestyle program focusing on two primary areas: weight loss and physical activity. These modifications have been shown to be more effective than medication alone in clinical trials.
Prevention programs aim for a modest weight reduction of 5% to 7% of initial body weight. For an individual weighing 200 pounds, this means losing only 10 to 14 pounds, a change that significantly improves insulin sensitivity and glucose metabolism. This weight loss is achieved through dietary changes, such as reducing overall calorie intake and focusing on healthier eating patterns.
The second core component involves increasing regular physical activity, which helps lower blood sugar and improve insulin response. The recommended goal is to engage in at least 150 minutes per week of moderate-intensity exercise, such as brisk walking. This activity level has been shown to reduce the risk of developing Type 2 Diabetes by nearly 60% over three years.
Structured programs, such as the National Diabetes Prevention Program (DPP), provide support and guidance for these changes. The DPP is a year-long program that utilizes trained lifestyle coaches and a CDC-approved curriculum. Engaging in these proven interventions offers the best chance to delay or prevent the onset of Type 2 Diabetes.