Glycosuria - Causes and Symptoms

Definition

Glycosuria indicates the presence of glucose in the urine.

Under normal conditions, this sugar is filtered by the renal glomerulus and is completely reabsorbed in the tubule, before the urine leaves the kidney to be collected in the bladder. However, if blood glucose levels are above 180-200 mg / dl on average, their presence in urine may begin to be detected.

Hyperglycemic glycosuria

Glycosuria can occur when the amount of glucose in the blood increases and exceeds the renal threshold (ie the ability of tubular reabsorption), therefore the kidneys are no longer able to prevent their elimination with urine. In this sense, glycosuria is the expression of a hyperglycemia correlated to an excessive introduction of sugars or to a pathology that modifies its regulation.

The disease that most typically involves hyperglycemic glycosuria is diabetes mellitus. For this reason, in addition to the determination of blood glucose in the blood, periodic monitoring of this parameter is recommended for diabetic subjects, as they are more exposed to the risk of hyperglycemia. By repeating this analysis on different urine samples, the effectiveness of treatment with insulin and other hypoglycemic drugs can be monitored.

It should also be considered that glycosuria makes the diabetic patient more susceptible to lower urinary tract infections.

Normoglycemic glycosuria

Glycosuria in the presence of normal or low levels of blood glucose can appear even when the kidneys are unable to reabsorb this sugar due to impaired functionality.

Normoglycemic glycosuria may depend on an acquired or hereditary defect of the renal tubule, mainly determined by the congenital deficiency of some enzymes or by advanced chronic kidney diseases.

Other causes of glycosuria

The excretion of glucose in urine may occur in the context of various systemic diseases, including Fanconi syndrome, cystinosis and Wilson's disease. This condition can also be associated with thyroid, adrenal and pituitary dysfunctions (eg acromegaly, Cushing's syndrome, hyperthyroidism and pheochromocytoma).

The presence of glucose in the urine can also result from chronic inflammation of the pancreas or from cancer processes affecting the organ itself. Glycosuria can also be found following nervous system injuries secondary to brain tumors, bleeding, poisoning (eg lithium and cadmium), anoxia and infectious diseases.

Other possible causes include hemochromatosis, cystic fibrosis, extensive burns, uremia, severe hepatic failure, sepsis and cardiogenic shock.