Maintenance of blood glucose level (homeostatis of blood sugar):

The blood glucose concentration depends on a wide variety of factors and its concentration at any time is the net result of equilibrium between the rates of entry and of removal of glucose in the circulation. As such, all the factors that exert influence on entry or removal become important in the regulation of blood glucose concentration.

Furthermore, when the renal reabsorptive capacity for glucose is exceeded (renal threshold), urinary loss of glucose becomes an additional factor influencing the maintenance of the blood glucose concentration.