CORRESPONDENCE

HYPERGLYCEMIA DURING PHYSICAL STRESS

To the Editor: Hyperglycemia occurring during

physical stress may be due to pre- viously undiagnosed diabetes mel- litus or the metabolic response to the stress. Determination of the cause impacts on both immediate and long-term management deci- sions. Therefore, I would like to add two clinical points to Dr. Mizock’s scholarly review of carbohydrate metabolism during stress.’

Four studies have specifically and clearly addressed hypergly- cemia upon presentation to the hospital.2-5 None of the patients had a known prior history of dia- betes mellitus or were receiving glucocorticoid therapy or intra- venous glucose.

In two of the studies, the acute stress was a myocardial infarc- tion.2J Of patients admitted with a blood glucose of 10 mmol/L (180 mg/dL) or higher, 63% proved (by glucose tolerance testing) to have diabetes mellitus at the time of re- covery. In addition, an elevated glycohemoglobin on presentation strongly supported the clinical suspicion of preexisting diabetes mellitus.2,3

In victims of major trauma the degree of hyperglycemia is posi- tively correlated with the severity of head injury@ as judged by the Glasgow Coma Scale (GCS). The GCS ranges from a best possible score of 15 seen in normals to a worst possible of 3 seen in those with deep coma. Only those pa- tients with a vegetative state or deep coma (GCS of 3) and even- tual fatal outcome had on admis- sion, blood glucoses over 13.8 mmol/L (250 mg&L).’ In one se- ries, all patients with this degree of hyperglycemia died.G

In patients with a GCS above 8, the finding at presentation of a blood glucose over 13.8 mmolLL (250 mg/dL) indicates that diabetes mellitus predated the traumatic event.45

Daniel Weiss, MD, FACP Case Western Reserve University

School of Medicine Cleveland, Ohio

1. Mizock BA. Alterations in carbohydrate

metabolism during stress: a review of the literature. Am J Med. 1995;98:75-84. 2. Husband DJ, Albert1 KG, Juhan DG. Stress

hyperglycemia during acute myocardial infarction: an indicator of pre-existing diabetes? Lancet.

1983;2:17%181. 3. Madsen JK, Haunsoe S, Helquist S, et al.

Prevalence of hyperglycaemia and undiagnosed diabetes melliius in patients with acute myocardial

infarction. Acta Med Stand. 1986;220:329-332. 4. Desai D, March R, Watters JM. Hyperglycemia after trauma Increases with age. J Trauma. 1989; 29:719-723. 5. Lam AM, Winn HR, Cullen BF, Sundling N.

Hyperglycemia and neurological outcome in patients with head injury. J Neurosurg. 1991;75:545-551. 6. Merguerian PA, Perel A, Wald U, et al. Persistent

non ketotic hyperglycemia as a grave prognostic sign in head-injured patients. Crit Care Med.

1981;9:838-840.

Manuscript submitted February 17, 1995 and

accepted April 3, 1995.

The Reply: Dr. Weiss raises the point that

not all hyperglycemia which oc- curs during critical illness can be attributed to “stress,n and that un- diagnosed diabetes mellitus should also be a consideration. He sup- ports his position by referring to two studies of patients with acute myocardial infarction who pre- sented to the hospital with hyper- glycemia.1a2 In these studies, when the cohort of patients who pre- sented with blood sugar in excess of 9 to 10 mmol/L (and who were not known to be diabetic) was ex- amined, approximately 60% were found to have abnormal glucose tolerance upon subsequent testing.

The authors correctly concluded that hyperglycemia waiS more like- ly a reflection of preexisting glu- cose intolerance than a stress-in- duced phenomenon. Myocardial infarction stimulates stress hor- mone release resulting in increased glucose appearance due to aug- mented glycogenolysls and gluco- neogenesis. Patients with underly- ing diabetes would be expected to have more substantial elevations in blood sugar as the result of this process. Nondiabetic patients with hypermetabolic stress (eg, trauma, burns) who manifest blood glucose in excess of 250 mg/dL generally have septic complications which impair glucose transport in some undefined wayt3a4

The preceding anatlysis should also have relevance for head trauma; patients who present with marked elevations ln blood sugar should be suspected to have un- derlying diabetes mellitus. How- ever, Dr. Weiss’ statement that “the finding at presentation of a blood glucose over 250 mg/dL indicates that diabetes mellitus predated the traumatic event” is not supported by the references cited.

Barry A. Mizoc,k, MD, FACP Medical Intensive Care Unit

Cook County Hospital Chicago, Illinois

1. Husband DJ, Alberti KG, Julian DG. Stress

hyperglycaemia during acute myocardial infarction: an indicator of pre-existing diabetes? Lancet.

1983;2:179-181. 2. Madsen JK, Haunsoe S, Helquist S, et al.

Prevalence of hyperglycaemia and undiagnosed diabetes melliius in patients with acute myocardial

infarction. Acta Med Stand. 1986;220:32%332. 3. Siegel JH, Cerra FB, Coleman B, et al.

Physiological and metabolic correlations in human

sepsis. Surgery. 1979;86:163-193. 4. Mizock BA. AIteratIons in carbohydrate

metabolism during stress: a review of the Ilterature.

Am J Med. 1995;98:75-84.

Manuscript submitted March 28, 1995 and accepted April 3, 1995.

374 March 1996 The American Journal of Medicine’ Volume 100