Prediabetes is a condition in which blood sugar levels are higher than normal but not high enough to be considered diabetes. It is often called impaired fasting glucose or impaired glucose tolerance. Most people with prediabetes do not experience any symptoms. However, if symptoms do occur, they may include increased thirst, frequent urination, blurred vision, and increased fatigue.
Prediabetes is more common in older people, those with a waist larger than 40 inches for men and 35 inches for women, people who eat a lot of red and processed meat, consume sugary beverages and low amounts of fruits, vegetables, nuts, whole grains, or olive oil, and in people who are Black, Native American, Latino, or Pacific Islander. Other risk factors include being overweight or obese, having high cholesterol, triglycerides, low HDL cholesterol, and high LDL cholesterol, not exercising, having a history of gestational diabetes, giving birth to a baby weighing over 9 pounds, having polycystic ovary syndrome, having a sleep problem like sleep apnea, or working changing shifts or night shifts.
Tests used to diagnose prediabetes include fasting plasma glucose test, oral glucose tolerance test, and hemoglobin A1c test. In fasting plasma glucose test, the blood is taken after an 8-hour fasting period. Normal results are less than 100 milligrams per deciliter (mg/dL), while prediabetes is 100 to 125 mg/dL, and diabetes is 126 mg/dL or higher. In the oral glucose tolerance test, the blood is taken after a sugary drink is consumed. Normal results are less than 140 mg/dL after the second test, while prediabetes is 140 to 199 mg/dL, and diabetes is 200 mg/dL or higher. The hemoglobin A1c test measures the average blood sugar levels for the past 2 to 3 months. Normal results are 5.6% or less, while prediabetes is 5.7 to 6.4%, and diabetes is 6.5% or above.
Complications of untreated prediabetes include kidney disease, blindness, high blood pressure, peripheral neuropathy, and amputation. Treatment for prediabetes involves eating a healthy diet, exercising, losing weight, stopping smoking, controlling blood pressure and cholesterol, and taking medication such as metformin to lower blood sugar levels. Making changes in one’s lifestyle, like choosing whole grains over processed carbs, drinking water instead of sugary drinks, and consuming good fats from vegetable oil, nuts, and seeds can help reverse prediabetes and lower the risk of type 2 diabetes.