High blood glucose or “blood sugar” levels put you at greater risk of developing insulin resistance, prediabetes and type 2 diabetes. Untreated diabetes can lead to many serious medical problems including heart disease and stroke. If you’re overweight AND you have at least one additional cardiovascular risk factor, your healthcare provider may recommend a blood glucose test. Your healthcare provider may also measure glycated hemoglobin A1c levels (A1c %) in your blood to screen for type 2 diabetes. An A1c level of 6.5% or higher is used to define diabetes.