This study is a retrospective chart review examining the utility of serum 1,5 anhydroglucitol as a measure of glycemic control in diabetics in outpatient endocrinology clinic. It is hypothesized the addition of testing for 1,5 anhydroglucitol will lead to significant reduction in hemoglobin A1c levels and testing for this may cause earlier reductions in A1c levels, and therefore improved glycemic control.