My nine year old son was showing low blood sugar levels 40 mg/dl [2.2 mmol/L] a year or so ago. He recently had a blood test that showed a low insulin level and a slightly elevated creatine level. He has also blacked out a couple of times in the past year. The doctor wants to retest him in six months and suspects possible diabetes onset. How does the creatine figure in?

A single fasting level of blood glucose of 40 mg/dl (2.2 mmol) a year ago is not an indication of Type 1 diabetes. It is not clear why the doctor asked for a serum creatine, I suspect it was just part of a standard test battery, and without knowing what the exact values were and what the normal range for the age group and the laboratory variance of the test these statement are not possible to interpret. Incidentally I could find absolutely no evidence that serum creatine levels have any bearing on the diagnosis of diabetes and personally I would not spend time looking for such an investigator.

DOB
Additional comments from Dr. Tessa Lebinger:

Are you sure your doctor didn’t measure carnitine, not creatine? Carnitine deficiency is unrelated to diabetes, can cause low blood sugars and other problems. If your child has passed out with low blood sugars, he needs a complete metabolic workup to rule out hormonal deficiencies such as growth hormone and cortisol deficiency, and other metabolic abnormalities that can cause low blood sugars and other medical problems.

TGL
Additional comments from Dr. Larry Deeb:

I honestly have no idea, unless you mean creatinine, which is used as a test of kidney function, instead of creatine.

LD