Differential Diagnosis for Glucosuria without Hyperglycemia or Diabetes
- Single most likely diagnosis
- Renal glucosuria: This condition is characterized by the kidneys' inability to reabsorb glucose properly, leading to its presence in the urine even at normal blood glucose levels. It's a benign condition and the most straightforward explanation for glucosuria without hyperglycemia.
- Other Likely diagnoses
- Pregnancy: During pregnancy, the kidneys' ability to reabsorb glucose can be impaired, leading to glucosuria without an increase in blood glucose levels. This is due to increased glomerular filtration rate and decreased renal threshold for glucose.
- Fanconi syndrome: A disorder of the proximal renal tubules where glucose, along with other substances like amino acids and phosphate, is excessively excreted in the urine. While it can lead to various metabolic disturbances, glucosuria can occur without hyperglycemia.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- SGLT2 inhibitor use: Medications that inhibit sodium-glucose cotransporter 2 (SGLT2) can cause glucosuria as a side effect by preventing glucose reabsorption in the kidneys. Although not a disease, missing this cause could lead to unnecessary investigations.
- Critical illness: In critically ill patients, stress-induced glucosuria can occur without hyperglycemia due to various factors, including changes in renal function and the use of certain medications.
- Rare diagnoses
- Genetic disorders affecting glucose transport: Rare genetic conditions can affect the function of glucose transporters in the kidneys, leading to glucosuria. Examples include isolated glucose galactose malabsorption and glucose-galactose malabsorption due to mutations in SLC5A1 and SLC5A2 genes.
- Nephrotoxicity from certain drugs or toxins: Certain drugs or toxins can cause renal damage, specifically to the proximal tubules, leading to impaired glucose reabsorption and glucosuria without hyperglycemia.