Historical review of the diagnosis of prediabetes/intermediate hyperglycemia: Case for the international criteria.
Level 5 - mechanism / opinion, no new human data
Narrative review without systematic search or meta-analysis
PubMed 35134465 · doi:10.1016/j.diabres.2022.109219
What was done
The author conducted a historical review comparing American Diabetes Association (ADA) and international diagnostic thresholds for prediabetes/intermediate hyperglycemia based on impaired fasting glucose (IFG) and glycated hemoglobin (HbA1c).
What was found
In 2003, the ADA lowered the fasting plasma glucose (FPG) cutoff for IFG from 6.1–6.9 mmol/L (110–125 mg/dL) to 5.6–6.9 mmol/L (100–125 mg/dL), a change not adopted internationally. The ADA also defined prediabetes as an HbA1c of 39–47 mmol/mol (5.7–6.4%), whereas Canadian and European guidelines use 42–47 mmol/mol (6.0–6.4%) and the WHO concluded prediabetes cannot be diagnosed by HbA1c. Under ADA criteria, approximately one-half of diagnosed individuals test normal on re-testing, one-third spontaneously revert to normal over time, and two-thirds never develop diabetes in their lifetimes. The review notes evidence linking intermediate hyperglycemia independently to cardiovascular disease is weak, with other metabolic syndrome risk factors responsible.
Why it matters
Lower diagnostic cutoffs may lead to widespread overdiagnosis of low-risk individuals. Higher international criteria capture individuals at higher risk of progressing to diabetes, which may better target and motivate preventive lifestyle interventions.
Limits
This is a narrative historical review and commentary, not a systematic review or meta-analysis. The abstract provides no source sample sizes, pooled risk ratios, or confidence intervals for the reported percentages of re-testing normalization, spontaneous reversion, or lifetime diabetes risk.
Cited by
- supports A hemoglobin A1c of 5.7% is the diagnostic threshold for prediabetes.