March 19, 2002
Blood Tests and Insulin Injections
Question from Bikaner, Rajasthan, India:
My eight year old daughter, diagnosed with type 1 diabetes three months ago, was initially under control, but currently when I check her urine, it shows 4+ glucose when her blood sugar is 143 mg/dl [7.9 mmol/L]. We compared her meter with the lab and got almost the same result.
My daughter’s doctor says that glucose only spills in the urine if blood glucose is over 180 mg/dl [10 mmol/L]. How it is this possible? Could it be a kidney disease or something else?
Answer:
The usual explanation for this is that the urine has been sitting in the bladder overnight, and the blood test is done before breakfast. Urine accumulates and so any high blood glucose levels during this period will result in glucose appearing in the urine even if the blood value then falls. It is also worth checking the strips to ensure that they are within their ‘use-by-date’. Blood results are more reliable.
KJR
