What are the diagnostic criteria and treatment options for diabetes?

From the Guidelines

Diabetes is diagnosed when a patient has a fasting blood glucose level of 126 mg/dL or higher, a hemoglobin A1C of 6.5% or higher, a random blood glucose of 200 mg/dL or higher with symptoms, or a 2-hour glucose of 200 mg/dL or higher during an oral glucose tolerance test, as recommended by the most recent guidelines 1. The diagnostic criteria for diabetes have been established based on the association between glucose levels and the presence of retinopathy, with the American Diabetes Association (ADA) affirming the use of the A1C test to diagnose diabetes with a threshold of 6.5% 1.

Diagnostic Criteria

The diagnostic criteria for diabetes include:

• Fasting plasma glucose (FPG) ≥ 126 mg/dL (7.0 mmol/L)
• 2-hour plasma glucose ≥ 200 mg/dL (11.1 mmol/L) during an oral glucose tolerance test (OGTT)
• Hemoglobin A1C (HbA1C) ≥ 6.5%
• Random plasma glucose ≥ 200 mg/dL (11.1 mmol/L) with classic symptoms of hyperglycemia or hyperglycemic crisis In the absence of unequivocal hyperglycemia, diagnosis requires confirmatory testing, which can be accomplished by repeating the same assay on a different blood sample or using a different assay, such as glucose or HbA1C 1.

Treatment Options

Treatment options for diabetes vary based on the type and severity of the disease.

• For Type 2 diabetes, first-line therapy typically includes lifestyle modifications and metformin, with additional medications added as needed, such as sulfonylureas, DPP-4 inhibitors, SGLT-2 inhibitors, GLP-1 receptor agonists, or insulin therapy.
• For Type 1 diabetes, insulin therapy is essential, typically using multiple daily injections or an insulin pump with basal insulin and mealtime insulin. Regular screening for complications affecting the eyes, kidneys, nerves, and cardiovascular system is necessary, with blood glucose monitoring crucial for all diabetes patients, aiming for a target HbA1C generally below 7% for most adults 1.

From the FDA Drug Label

Type 2 diabetes is a condition in which your body does not make enough insulin, and the insulin that your body produces does not work as well as it should. Your body can also make too much sugar. When this happens, sugar (glucose) builds up in the blood. This can lead to serious medical problems The main goal of treating diabetes is to lower your blood sugar to a normal level.

• Diagnostic criteria for diabetes are not explicitly stated in the provided drug labels.
• Treatment options for diabetes include:
  • Diet and exercise
  • Certain medicines, such as metformin 2 and pioglitazone 3
  • Insulin therapy 4 It is essential to consult a healthcare provider to determine the best course of treatment for individual patients.

From the Research

Diagnostic Criteria for Diabetes

• The diagnosis of diabetes can be made if hemoglobin A1c (HbA1c) level is greater than or equal to 6.5% and confirmed with a repeat HbA1c test 5
• Fasting plasma glucose, 2-hour postglucose-load plasma glucose, and oral glucose tolerance tests are recommended for the diagnosis of diabetes only if HbA1c testing is not possible 5
• Combining the use of HbA1c and plasma glucose measurements for the diagnosis of diabetes offers the benefits of each test and reduces the risk of systematic bias inherent in HbA1c testing alone 5, 6, 7

Treatment Options for Diabetes

• Metformin is the first-line treatment for patients with Type 2 diabetes, and additional therapy is dependent on multiple patient-specific factors 8
• Sulfonylureas and Dipeptidyl Peptidase-4 (DPP-4) inhibitors are considered as second-line therapies for Type 2 diabetes, with sulfonylureas being more efficacious in lowering HbA1c but having a higher risk of hypoglycemic events 8
• DPP-4 inhibitors may be considered as a clinically stable choice for second-line therapy after completing maximally tolerated doses of metformin, especially in patients with a high risk of hypoglycemia 8

Screening for Diabetes and Impaired Glucose Tolerance

• The combined use of fasting plasma glucose and HbA1c can be used as a screening test for diabetes and impaired glucose tolerance in high-risk subjects 7
• The optimal cut-point for fasting plasma glucose and HbA1c to diagnose diabetes is greater than or equal to 6.1 mmol/l and 6.1%, respectively, with a sensitivity and specificity of 81.5% and 81.0% 7
• The use of fasting glucose and HbA1c together can improve the identification of individuals who have diabetes, allowing clinicians to streamline the use of the oral glucose tolerance test 9