Correspondence

Alteration in Glucose Metabolism by Crying in Children

N Engl J Med 1993; 329:1129October 7, 1993

Article

To the Editor:

In caring for children undergoing surgery, we noted that some of them had blood glucose concentrations greater than 120 mg per deciliter. To determine whether emotional stress was the cause of these elevations, we studied 28 healthy boys one to three years old who underwent circumcision. They were assigned by two anesthesiologists to one of two groups, depending on their attitude before anesthesia: a calm group, composed of those who were sleeping or sleepy (16 boys); and a crying group, consisting of those who were crying and resisted the induction of anesthesia (12 boys). They had not been allowed to eat any solid food after midnight, but they were encouraged to drink fluids until two hours before anesthesia was induced (halothane in oxygen). Immediately after the disappearance of the eyelash reflex, we obtained a sample of venous blood for measurement of blood glucose (glucose oxidase method) and plasma lactic acid (lactic acid analyzer).

The blood glucose and plasma lactic acid concentrations were significantly higher in the crying group (Table 1Table 1Blood Glucose and Plasma Lactic Acid Concentrations and Maximal Heart Rate in Crying and Calm Boys during Induction of Anesthesia.). There was a significant correlation between the glucose and lactic acid concentrations in the crying group (r = -0.82, P<0.001) but not in the calm group (r = 0.49).

It is tempting to think that crying is routine and harmless. In this study, however, we found significantly elevated heart rates and blood glucose and plasma lactic acid concentrations in the crying children. In adults, emotional stress before operation causes elevation of the heart rate and levels of stress-related hormones1,2. Although we did not determine the concentrations of those hormones, the elevation of the blood glucose concentration suggests they were elevated in the crying group.

Plasma lactic acid and blood glucose concentrations increase during exercise3; these changes are followed by a gradual decrease in glucose concentrations and a further elevation in lactic acid concentrations4. Thus, the metabolic changes in the crying group were similar to those that occur in adults during exercise. The metabolic changes in crying and struggling children may be similar to those in adults under emotional as well as physical stress.

Jun Aono, M.D.
Wasa Ueda, M.D.
Masanobu Manabe, M.D.
Kochi Medical School, Kochi, 783 Japan

4 References

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   Salmon P, Evans R, Humphrey DE. Anxiety and endocrine changes in surgical patients. Br J Clin Psychol 1986;25:135-141
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   Coggan AR, Coyle EF. Metabolism and performance following carbohydrate ingestion late in exercise. Med Sci Sports Exerc 1989;21:59-65
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   Stainsby WN, Brooks GA. Control of lactic acid metabolism in contracting muscles and during exercise. In: Pandolf KB, ed. Exercise and sports science reviews. Vol. 18. Baltimore: Williams & Wilkins, 1990:29-63.