This gets cited here weekly, usually second-hand, so it is worth setting out what it does and does not establish.
HbA1c reflects roughly three months of average glycaemia weighted toward the most recent weeks, which is why repeating it at six weeks tells you very little. The improvement on this class comes from two directions — direct glucose-dependent insulin secretion and glucagon suppression, plus the indirect effect of weight loss on insulin sensitivity — and the second continues after the first has plateaued.
Where I think it is weakest: the comparator does most of the work in how this gets reported, and it is not the comparator most people think they are citing.
What I am after is why A1C lags the way it does, and what to look at in the meantime if you want to know sooner. If the honest answer is that nobody knows, that is a useful answer and I would rather have it.
Figures above are from the primary publication rather than the press summary. If a number here disagrees with one you have, post yours and we will work out which of us is reading a secondary source.
Dr.MetabolicMD said:HbA1c reflects roughly three months of average glycaemia weighted toward the most recent weeks, which is why repeating it at six weeks tells you very…
My labs after 6 months on glycaemic control: A1C 6.1%, fasting glucose 76 mg/dL, fasting insulin 9 uIU/mL. My endo says these are "textbook perfect."
For context, my baseline A1C was 6.7% and fasting glucose was 121 mg/dL. The improvement has been dramatic and consistent.
Dr.MetabolicMD said:HbA1c reflects roughly three months of average glycaemia weighted toward the most recent weeks, which is why repeating it at six weeks tells you very…
Glycemic variability as the key metric for glycaemic control success: my coefficient of variation (CV) on CGM dropped from 42% to 22%. Target is <36%, with <30% being ideal.
Why this matters more than average glucose: large glucose swings cause oxidative stress, endothelial damage, and promote advanced glycation end-products (AGEs). A flat glucose line at 95 mg/dL is metabolically healthier than oscillating between 60 and 160, even if the average is the same.
Sigma-Aldrich — Research-Grade Standards
Certified reference materials, analytical reagents, and research-grade standards for peptide verification. Trusted by laboratories worldwide.
Shop Reference Standardsjulia.endo said:Glycemic variability as the key metric for glycaemic control success: my coefficient of variation (CV) on CGM dropped from 42% to 22%.
Complete metabolic panel trending on glycaemic control — sharing because comprehensive data helps everyone:
| Test | Baseline | Month 3 | Month 6 | Month 12 |
|---|---|---|---|---|
| Glucose (fasting) | 130 | 100 | 94 | 84 |
| Insulin (fasting) | 26 | 14 | 10 | 7 |
| HOMA-IR | 4.5 | 3.6 | 2.2 | 1.4 |
| Uric Acid | 8.3 | 7.0 | 6.1 | 5.1 |
The insulin resistance improvement (HOMA-IR) is what my endo focuses on most. Going from 4.5 to near 1.0 is a metabolic transformation.
Dr.ReproEndo said:My labs after 6 months on glycaemic control: A1C 6.1%, fasting glucose 76 mg/dL, fasting insulin 9 uIU/mL.
Second this.