HbA1c: do the latest BG samples count for more?

[Boerenkool]

@Michel

if you make a change of BG, then wait 30 days to an A1c, the (short term) A1c you get already reflects 50% (roughly) of what the final A1c for the new BG would be, 120 days after the change?

Exactly, if a step change of average BG is introduced at t=0 and kept constant, then the observed difference in A1c at t=30 reflects 50% of the predicted difference in A1c at t=120.

@Michel

In that case, what this would say is that, if you have a change of (average) BG 30 days before the end of your A1c interval, your actual A1c after these 30 days will be reflective of 50% of the change to what it would be if you stayed at that level for another 90 days, then measured the A1c.

Right, in that case your A1c at the end of your A1c interval will be reflective of 50% of the change in A1c between 30 days before the end of the interval and 90 days after the end.