RickReta_CO said:

A defensible baseline is short: HbA1c and fasting glucose, a lipid panel with ApoB if you can get it, ALT and AST, creatinine with eGFR, TSH, ferritin…

No disagreement with RickReta_CO. One condition attached. The single most useful discipline is bringing the whole panel to a clinician rather than one flagged value. One out-of-range result in isolation generates anxiety and unnecessary tests; the same result next to the trend and the rest of the panel usually generates a shrug.

RickReta_CO said:

A defensible baseline is short: HbA1c and fasting glucose, a lipid panel with ApoB if you can get it, ALT and AST, creatinine with eGFR, TSH, ferritin…

I read this differently from RickReta_CO, on substance rather than tone. I would drop the "get everything" instinct further than this thread does. Every extra test is another chance at a false positive, and incidental findings have their own cost in scans, biopsies and worry.

Answering the narrow version, because the broad one does not have a single answer. Quarterly for the first year is convention rather than evidence, and it is defensible for a simple reason: it is roughly the interval over which HbA1c becomes informative again, since it reflects about three months of glycaemia. After the first year, and once doses are stable, annual is reasonable unless something specific is being followed.

NurseKim_ATL said:

The single most useful discipline is bringing the whole panel to a clinician rather than one flagged value.

Can confirm. Same sequence, different timescale.