A1C (glycated hemoglobin)

Definition

A blood test reflecting average blood glucose over the prior 8-12 weeks, measured as the percentage of red-blood-cell hemoglobin glycated by glucose. Used as the primary endpoint in T2D trials. Diagnostic threshold: ≥6.5% = diabetes; 5.7-6.4% = prediabetes; <5.7% = normal. GLP-1 receptor agonists typically reduce A1C by 1.0-2.0 percentage points at maximum dose — clinically meaningful, because each 1-point drop reduces microvascular complication risk roughly 25-35%.

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Definition curated by Weight Loss Rankings — sourced from FDA labels and peer-reviewed PubMed literature, never AI-generated summaries.

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