Stress hyperglycemia during infection
Urinary tract infection (UTI) can be associated with elevated blood glucose due to an acute stress response. Infections increase counter-regulatory hormones (eg, catecholamines and cortisol) and inflammatory signaling, which can raise blood glucose even in people without known diabetes.
Evidence linking stress hyperglycemia and infection
Higher stress hyperglycemia measures have been associated with infectious complications in acute illness cohorts, including increased odds of urinary tract infection in stroke patients with higher stress hyperglycemia ratio. [1]
Mean perioperative glucose levels >220 mg/dL were associated with substantially higher risk of perioperative infectious complications in patients without known diabetes, with urinary tract infection included among observed infections. [2]
Clinical implications for elevated glucose during UTI
Elevated glucose during a UTI may represent stress hyperglycemia rather than previously unrecognized diabetes. [1]
Persistently elevated glucose beyond resolution of the UTI increases the likelihood of underlying dysglycemia or diabetes and warrants follow-up testing. [1]
When urgent evaluation is needed
Immediate evaluation is needed for markedly elevated glucose with symptoms concerning for hyperglycemic emergencies (eg, dehydration, vomiting, abdominal pain, rapid breathing, confusion) and for fever with systemic illness features suggesting complicated infection or sepsis.
Practical next steps
A repeat blood glucose assessment after treatment of the UTI (or after clinical improvement) is appropriate to determine whether hyperglycemia resolves. [1]
Screening for diabetes is appropriate when elevated glucose persists or when there is recurrent hyperglycemia during infections.
Confirming the UTI contribution
UTI-related hyperglycemia cannot be confirmed from glucose measurements alone. A urine infection should be evaluated and treated based on urinary symptoms and objective testing (urinalysis and urine culture when indicated), while glucose elevation is assessed in parallel.