Prediabetes is an intermediate stage between normal blood sugar levels and diabetes.
Its history reflects the evolution of medical knowledge and efforts to prevent type 2 diabetes, a disease that affects millions of people worldwide.
1997: The beginnings
The American Diabetes Association (ADA) created the category of pre-diabetes in 1997, defining an initial criterion based on fasting blood glucose levels.
- A blood glucose level of 110 to 125 mg/dL (6.1-6.9 mmol/L) was considered a sign of prediabetes.
- This definition was quickly adopted by the World Health Organization (WHO).
The aim was simple: to identify people at risk and intervene before they developed diabetes.
2003: A lower threshold
In 2003, the ADA lowered the fasting blood glucose threshold for pre-diabetes to 100-125 mg/dL (5.6-6.9 mmol/L).
Why this change?
The researchers found that, among people diagnosed with prediabetes, those with high fasting blood glucose levels (110-125 mg/dL) were less likely to progress to diabetes than those identified by another test, induced hyperglycemia (IGH), which measures blood glucose levels two hours after glucose ingestion.
By lowering the fasting blood glucose threshold to 100 mg/dL, more people at risk are included, bringing the number of people diagnosed as pre-diabetic by fasting blood glucose closer to that identified by OGTT. This makes it possible to better balance the results of the two methods, even if it sometimes means including individuals who will not progress to diabetes.
2008: The arrival of HbA1c
A new player enters the picture: HbA1c, a marker measuring the average blood glucose level over the last 2-3 months.
Experts suggest diagnosing diabetes with an HbA1c ≥ 6.5% (48 mmol/mol).
For pre-diabetes, they suggest an HbA1c between 6.0% and 6.4% (42-48 mmol/mol), indicating a need for close monitoring and early intervention.
However, the WHO is more cautious. It adopts the HbA1c criterion for diabetes, but does not set a specific threshold for prediabetes, deeming the evidence insufficient.
2016: The ADA goes further
The ADA makes a bold decision:
It defines a new range for prediabetes, with an HbA1c of 5.7% to 6.4% (39-48 mmol/mol).
This criterion, based on epidemiological data, broadens the number of people identified as being at risk of diabetes.
The history of Prediabetes shows that diabetes screening and prevention are constantly evolving.
With tools like HbA1c and a better understanding of risk factors, healthcare professionals can intervene earlier and help reduce the impact of diabetes in the population.
The challenge is to find the right balance between identifying enough people at risk without overdiagnosing them.
Learn more about Pep2Dia to maintain a healthy glycemia!
Sources:
A Reappraisal of Prediabetes
Mayer B. Davidson, Richard A. Kahn
The Journal of Clinical Endocrinology & Metabolism, Volume 101, Issue 7, 1 July 2016, Pages 2628–2635,
https://doi.org/10.1210/jc.2016-1370