Lab

Urine Glucose

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Urine Glucose, Glycosuria, Urine Dipstick Glucose, Renal Threshold for Glucose

  • See Also
  • Definitions
  1. Renal Threshold for Glucose (RTg)
    1. RTg is the Serum Glucose level above which Glucose spills into the urine and is not reabsorbed
    2. Glucose reabsorption is mediated by Sodium-Glucose Cotransporter 2 (SGLT-2) at the proximal tubule
    3. Above the RTg, SGLT-2 is overwhelmed and cannot absorb additional Glucose
    4. RTg >170 to 200 mg/dl (typically listed as 180 mg/dl) in non-diabetic patients
    5. RTg >200 to 250 mg/dl in Type 2 Diabetes Mellitus
    6. Osaki (2016) J Diabetes Investig 7(5):751-4 +PMID: 27181936 [PubMed]
  • Causes
  • Renal Causes of Glucose in the urine
  1. Signs suggestive of Renal Tubular disease
    1. Serum Glucose <180 mg/dl
    2. Glucose Tolerance Tests are normal
    3. Ketosis absent
  2. Specific Causes
    1. Fanconi Syndrome
      1. Glycosuria despite a normal Serum Glucose
      2. Associated with multiple Electrolyte abnormalities
    2. Pregnancy
    3. SGLT2 Inhibitor (Sodium-Glucose Co-Transporter-2 Inhibitor)
    4. Toxic renal tubular disease
      1. Lead Toxicity
      2. Mercury Toxicity
      3. Degraded Tetracycline
    5. Inflammatory renal disease
      1. Acute Glomerulonephritis
      2. Nephrosis
    6. Increased GFR without tubular damage