Diagnostic criteria for diabetes
Key points
  • Diabetes mellitus is a severe chronic disease that occurs in the production of insulin by the body, or a violation of its effective use against the background of sufficient production. There are 3 main types of diabetes mellitus: type 1 diabetes mellitus, type 2 diabetes mellitus and gestational diabetes mellitus.
  • Type 1 diabetes most often occurs in childhood but can occur at any age. At this time, it cannot be prevented. People with type 1 diabetes can only live full lives with an uninterrupted supply of insulin, sufficient awareness, support, and the availability of blood glucose testing equipment.
  • Type 2 diabetes mellitus accounts for the vast majority (about 90%) of diabetes worldwide. It is possible to effectively influence its occurrence and course through education, support and adoption of a healthy lifestyle in combination with medication, if necessary.
  • "Prediabetes" is a term that is increasingly used for people with impaired glucose tolerance and / or with impaired fasting glucose. It determines the risk of future development of type 2 diabetes and diabetes-related complications.
  • Pregnant women with gestational diabetes may have high blood sugar, blood pressure, and high birth weight in babies as a result of gestational diabetes, which increases the risk of pregnancy and childbirth complications for both mother and baby.
Most guidelines use standard diagnostic criteria suggested by the IDF and the World Health Organization (WHO)
WHO supports the use of HbA1c> 6.5% for diagnosing diabetes but not for intermediate hyperglycaemia, on the grounds that guaranteed quality HbA1c measurement is not available globally. Currently, the WHO recommends a two-hour oral glucose tolerance test (OGTT) to detect IGT and IFG. However, there is cumulative evidence for the use of one-hour OGTT as a more sensitive method capable of identifying intermediate hyperglycemia at an earlier point in time.

For type 1 diabetes in the presence of symptoms (eg, polyuria, polydipsia, and unexplained weight loss), the diagnosis can be made without OGTT if present: a random vein plasma glucose concentration ≥ 11.1 mmol/L or a fasting plasma glucose concentration ≥ 7.0 mmol/L (whole blood ≥ 6.1 mmol/L or HbA1c ≥6.5%).