I can tell you my microalbumin numbers bounce up and down a lot from lab test to lab test, but my doc always says to ignore those variations and only look at the ratio.
The normal range for the ratio at most labs is “Under 30”.
I’ve often asked my doc if say, a ratio of 15 is of more concern than a ratio of 10, and he’s always told me no, as long as the number is under 30 there’s nothing to worry about.
Kids often have a wider range of variations on lab tests than adults.
You mention the A1C but another important risk factor for kidney disease is blood pressure. With all the emphasis on A1C’s and bg control sometimes I think we forget to think about the blood pressure risk factors for several of the complications.
The interesting thing about the association of kidney disease and hypertension is that hypertension is both a cause and a consequence of declining renal function, since the kidney plays an important role in maintaining normal blood pressure. So distinguishing cause and effect here can be difficult.
Another factor that people tend to ignore in tracing the genesis of diabetic nephropathy is the considerable role of genetics in determining which diabetics are susceptible to this complication and which are not. (1) So remember, always pick the right family to be born into.
(1) H. Gu and K. Brismar, “Genetic Association Studies in Diabetic Nephropathy,” Current Diabetes Reviews, 8 (5) 336 (2012); A. McKnight, et al., “Genetics of Diabetic Nephropathy,” Current Diabetes Reports, 15 (7) 41 (2015).