GLUCOREGULATORY DISORDERS IN SCHOOL REFUSAL STUDENTS

OBJECTIVES Our previous studies demonstrated autonomic nervous system disorders and cerebral blood hypoperfusion in school refusal students with underlying emotional distress due to fear or anxiety associated w ith school attendance. Because severe stress is known to affect glucor egulatory metabolism, this study used the oral glucose tolerance test (OGTT) to measure glucose metabolism in school refusal students. DESIG N A three-hour OGTT was performed. In preparation for the test, studen ts fasted overnight. After a fasting blood sample was drawn, students were given solutions containing a predetermined amount of glucose base d on their body weight (1.75 g/kg to a maximum 75 g). After glucose in gestion, blood samples were drawn at 30, 60, 90, 120, 150, and 180 min to measure blood glucose (BG), immunoreactive insulin (IRI), pancreat ic glucagon (IRG) and growth hormone (GH) levels. BG levels, IRI respo nse, cumulative BG (Sigma BG), cumulative IRI (Sigma IRI), insulin/glu cose ratio (Delta IRI/Delta BG), and insulinogenic index (Sigma IRI/Si gma BG) were then compared to previously reported normal control data. As an index of emotional difficulties, the self-rating depressive sca le (SDS) was carried out. PATIENTS Eighty-one school refusal students (40 males and 41 females), 11-19 years of age (14.8 +/- 2.1), were stu died. Their school refusal periods ranged from one month to eight year s. All students were within -15 to + 20% (-0.04 +/- 8.6) of ideal body weight. MEASUREMENTS BG levels were determined using a glucose oxidas e reaction method. Serum hormones were measured by radioimmunoassay. R ESULTS BG levels at all OGTT time intervals and Sigma BG were signific antly higher in school refusal students than the normal control data ( Sigma BG: 39.5 +/- 4.4 vs 33.3 +/- 3.4 mmol/l, P < 0.01). Although the insulin response was abnormally low relative to the prevailing hyperg lycaemia (Sigma IRI/Sigma BG: subjects vs control = 232 +/- 129 vs 375 +/- 271, P < 0.01), normal beta cell secretory ability was speculated (Sigma IRI: subjects vs controls = 2805 +/- 1274 vs 2523 +/- 1219 pmo l/l). This suggests a relative suppression of insulin secretion. A par adoxical increase of GH was observed in 19 students after glucose inge stion. CONCLUSIONS Glucoregulatory disorders observed in school refusa l students may be caused by emotional distress. Multiple factors inclu ding autonomic nervous system disorders, derangement of neuropeptides in the hypothalamus, and hormonal imbalances may also affect glucoregu latory metabolism, predisposing these students to hyperglycaemia. We s peculate that the glucoregulatory system compensates for decreased blo od flow to the brain by increasing blood glucose concentrations, there by providing sufficient glucose as the primary energy source used duri ng normal brain metabolism.