August 21, 2003
Diagnosis and Symptoms
Question from Round Lake, Illinois, USA:
About seven or eight months ago, we told the pediatrician that we noticed our son would be shaking sometimes when he woke up from a nap or in the morning. A blood glucose was normal, so he sent us to a neurologist who noticed it too and ordered some blood tests. Everything was normal except for an elevated lactic acid and BUN/creatinine ratio. All the doctors think my son is fine, and neurologically I think he is fine too, but I started to do a little investigating because the lactic acid being high worried me.
I spoke with a nurse friend of mine who suggested that I monitor his blood glucose myself at home. For the past few days, I’ve been monitoring his glucose and I’ve gotten readings anywhere from 44 to 216 mg/dl [2.4 to 12 mmol/L]. In fact, the day that he was 216 mg/dl [12 mmol/L], I tested him the first thing that morning (after not eating for 12 hours) and he was 127 mg/dl [7.1 mmol/L] (which I read is considered to be diabetes on two or more occasions). His lowest reading for that day was 167mg/dl [9.3 mmol/L] (out of three times) which was right after his nap. The thing that has me confused is that on the next day I tested him in the morning and it was 70 mg/dl [3.9 mmol/L]. Then, right before lunch after not eating for 4 hours it was 133 mg/dl [7.4 mmol/L].
I don’t think my son has full-blown type 1 diabetes yet, but I do think it is possible that his beta cells are slowing being destroyed, and since his body is not making energy right all the time, it is dumping the lactic acid into his blood slowly. My fear is that he will develop DKA [diabetic ketoacidosis], and I’m not sure what to do. Am I on to something? Should I continue to monitor his blood sugar or should I leave it alone?
The pediatrician ordered another fasting glucose, urinalysis and lactic acid, but his blood sugar patterns are so up, down and normal I don’t want to put my son through the testing if they happen to draw his blood on a good day and everything comes back normal. Is there some sort of pattern I should look for?
Answer:
This is an axiom that I find very helpful: “The most common cause of an abnormal laboratory test — is an abnormal laboratory.” I do not think I would be too concerned over an essentially isolated elevated lactic acid level (you did not give the actual value and the reported reference range) in a child in whom I am presuming is growing appropriately, developing appropriately, performing reasonable in school, etc.
The capillary glucose meters are nice screens, but they are not perfect. I do not deny any of the values that you have found. I would strongly suggest that you be certain that his fingers are completely clean and dry prior to testing. The value of 133 mg/dl [7.4 mmol/L] “4 hours after eating” doesn’t faze me yet. Even the value of 127 mg/dl [7.1 mmol/L] upon awakening does not yet faze me — one cannot make a diagnosis of diabetes from meter readings since they are not that sensitive.
Without looking at all the records, I will presume that your son is experiencing a process often called ketotic hypoglycemia which is usually benign. I would consider repeating some fasting, venipuncture (blood from a needle stick in a vein) results again to include, glucose, lactic acid, renal function, and a urinalysis.
The “high BUN/creatinine ratio” usually only reflects a bit of dehydration which can lead to mild lactic acid build up. Again, this discussion is predicated that your son actually has underlying good health without (known) chronic illness, mental retardation, poor growth. Your son’s pediatrician can best guide you.
DS
