dR symbol


Neuroglycopenia Recognition

Stefan Du Rietz  (e-mail: sdr (at) this domain)


Problems concerning detection of glucose deficiency

Glucose deficiency (generally confused with hypoglycaemia, see below), gives rise to two kinds of symptoms. The adrenergic symptoms become impaired or even absent after long duration of type 1 diabetes [1]. In contrast, the neuroglycopenic symptoms always remain, since they are the direct result of the deficient supply of glucose to the central nervous system (CNS). However, these symptoms involve deterioration of the cognitive capacity, so it may be difficult to take corrective measures. That could become a serious problem, generally called "hypoglycaemia unawareness" [2].

Unfortunately, hypoglycaemia is an ambiguous concept. There is no single compartment in the body at which all glucose is at the same concentration [3]. Because the uptake of glucose is from the interstitial fluid (ISF) surrounding the target cells and the supply is into the bloodstream, the concentrations will be unequal under dynamic conditions. When the uptake of glucose is larger than the supply, its concentration will decrease earlier in the ISF than in the blood [4]. On the other hand, when the supply of glucose is larger than the uptake, its concentration will increase earlier in the blood than in the ISF.

Further, not even is the glucose concentration the same in different parts of the ISF, because the uptakes of the cells at different locations are unequal. For instance, working muscles take up more glucose than resting muscles and their uptake is not proportional to the local glucose concentration [5].

Consequently, whereever you make the measurements, the glucose deficiency will not be optimally detected. So, all glucose measurements, both in the blood and in the ISF, must be interpreted with the utmost care.

The method

For an individual with long-standing type 1 diabetes, it is important to train and continually practise the ability to recognize early signs of CNS glucose deficiency (neuroglycopenia).

As yet, blood glucose (BG) is the only glycaemic state that you can measure in real time. Despite the aforementioned drawbacks, it is possible to get some valuable information from BG readings. It is extremely important, however, to have an accurate BG meter, because otherwise it will only give confusing information. If you cannot correlate the meter readings with any neuroglycopenic symptoms, it will be even more difficult to recognize those symptoms. Very few BG meters are good enough at low BG levels [6] and of course the "Clarke error grid" must not be used in evaluating BG meters for detection of low BG levels.

The BG meter must be constantly available so that you are able to use it immediately whenever you feel anything unusual. All the time you must be prepared to notice possible signs of neuroglycopenia, including concentration problems, difficulties to remember or associate, and weak feelings of unreality. When a regular BG reading is low, there is a particular opportunity to do so.

A personal comment

Being a type 1 diabetic myself, I have successfully applied this method for several years and have thus been able to avoid "serious hypoglycaemias", which I frequently had before. A remarkable fact is that it was not until I started to use a Life Scan One Touch Profile blood glucose meter (with better precision at low blood glucose readings [6]) instead of a Boeringer Mannheim Reflolux S that I managed to get rid of them.


References:

  1. Gerich JE, Langlois M, Noacco C, Karam JH, Forsham PH: "Lack of glucagon response to hypoglycemia in diabetes: evidence for an intrinsic pancreatic alpha cell defect." Science 182(108): 171-3, 1973. Abstract
  2. Cryer PE: "Hypoglycemia risk reduction in type 1 diabetes." Exp Clin Endocrinol Diabetes 109 Suppl 2: S412-23, 2001. Abstract
  3. Zierler K: "Whole body glucose metabolism." Am J Physiol Endocrinol Metab 276: E409-26, 1999. Abstract  Full text (HTML)  Reprint (PDF)
  4. Moberg E, Hagström-Toft E, Arner P, Bolinder J: "Protracted glucose fall in subcutaneous adipose tissue and skeletal muscle compared with blood during insulin-induced hypoglycaemia." Diabetologia 40(11): 1320-6, 1997. Abstract
  5. Zierler K, Andres R: "Muscle glucose uptake does not increase when only local arterial glucose concentration is increased." Diabetes 51: 2698-702, 2002. Abstract  Full text (HTML)  Reprint (PDF)
  6. Trajanoski Z, Brunner GA, Gfrerer RJ et al: "Accuracy of home blood glucose meters during hypoglycemia." Diabetes Care 19: 1412-5, 1996. Abstract

du Rietz | Type 1 Diabetes

Valid XHTML 1.0! Valid CSS!

@MEMBER OF PROJECT HONEY POT
Spam Harvester Protection Network
provided by Unspam