March 29, 2012
Diagnosis and Symptoms
Question from Europe:
My six-year-old son has a respiratory viral infection and a fever as high as 39.7 C (103.5 F). We gave him some paracetamol and he felt better. This is the second day of his infection and we will go to see the doctor today. My son is not diabetic. Yesterday, I checked his urine sample for ketones, just to be sure he is taking enough food and water. He peed first thing in the morning (that sample was not checked) and then next time maybe 8 to 10 hours after that. I know this is not good, but he simply didn’t want to drink and ate only relative small amounts of food. In that sample, I found some ketones (no surprise), but also some glucose, 0.25%. No need to say that I was horrified. After that, I checked his urine every time he peed (three times all together–amounts of urine were not excessive) but found no glucose, and ketones were on and off, depending of how much he ate. When he didn’t starve, his ketones were negative. He does not show any of typical signs of diabetes, like polydipsia, polyphagia or frequent urination. I wasn’t able to check his blood glucose yet, but certainly will. I know how DKA looks like and I’m quite positive that he doesn’t have it. I have three possible explanations of his glycosuria in one sample:
He is in the early stages of diabetes and his glycosuria is consequence of high blood glucose which didn’t persist thanks to the fact that diabetes is still at the beginning.
That glycosuria is indeed related to the high blood sugar, but the hyperglycemia was caused by his febrile condition. He may or may not develop diabetes.
His blood glucose was not elevated but his urine was too concentrated, and the amount of glucose was detectable due to the lack of water in urine. I know that healthy person spills some glucose in their urine but not enough to be detected by a home test strip. Is this scenario possible at all, that urine becomes so concentrated due to the lack of drinking and peeing?
Answer:
I think your three possible explanations are exactly correct. Urine glucose only represents that amount of sugar/glucose that exceeds the kidney threshold and, therefore, shows up in the urine. With persistent high blood glucose levels/hyperglycemia, the threshold is exceeded and thus urine glucose is weakly positive as you describe. This small amount is not worrisome unless it persists or becomes more elevated – or if high glucose symptoms occur: polyuria, polydipsia, nocturia, enuresis, unexplained weight loss, etc. Then, blood glucose testing would be significantly more reliable as an index of glucose than urine glucose. When someone is ill with an infection such as you describe, not eating causes the body to move to burning fat for energy and thus ketones show up in the urine (or blood). Negative glucose urine testing and positive ketone testing under these circumstances is quite common, of course. If there is any doubt, some more blood glucose testing at home would be helpful and, if still borderline, thena more formal evaluation by your physician would be in order.
SB
