RENAL THRESHOLD

The said term is of no consequence to a confirmed/prospective diabetic. It simply means that there is a simultaneous rise of sugar in the urine alongwith rise in sugar in the blood. Generally, there is hardly any rise of sugar in urine when blood sugar level remains upto 150-160 but when it exceeds that limit, there will be corresponding rise of sugar (glucose) content in the urine also. A trace of sugar in urine does indicate that blood sugar level has exceeded the normal limits. As the level of sugar rises in blood, so does the sugar level rise in urine too which position is taken to be ‘Normal Renal Threshold’ and anything contrary to the above facts will point out to ‘Disturbed Renal Threshold’.

There are certain exceptions to two varying situations described heretofore, that is to say that, in some patients, rise in blood sugar level may not show even a trace of sugar in urine and also, in other patients, reverse may be the case. A diseased or infected kidney may be said to be cause for the aforesaid two variable situations. The diabetics need not bother or get unduly worried about the said variations, as it is the job of the physician to look to such technicalities.

If, however, the renal threshold is low but the urine test in diabetes indicates presence of glucose in blood it clearly indicates that urine test is not only misleading but also points an accruing finger on the lab technician (s). It is also true that renal threshold of each patient varies – one may be normal for the one may be abnormal threshold for the other and vice versa. Urine tests after regulated gaps, will indicate an individual’s own renal threshold. But, all said and done, it cannot be said with certainty that glucose tests in urine and blood samples could be real parameters of renal threshold. Better, rely on your blood sugar tests, as amount of glucose spillover to urinary stream may be misleading. So, true diabetes can be detected by presence of glucose in blood only.