Monitoring of blood glucose concentration in subjects with hypoglycaemic symptoms during everyday life.

Abstract

OBJECTIVE--To study the persistence of hypoglycaemic symptoms, changes in blood glucose concentrations, and the relation between reported symptoms and measured blood glucose values in functional hypoglycaemia. DESIGN--Re-evaluation of symptoms in patients admitted consecutively with suspected hypoglycaemia followed by a case-control study. SETTING--The Steno Memorial Hospital in Gentofte, Denmark, which specialises in the diagnosis and treatment of and research on endocrine disorders, including hypoglycaemia. PATIENTS--21 Subjects admitted consecutively with hypoglycaemic symptoms that were relieved by eating in whom insulinoma and other organic disorders presenting with hypoglycaemia had been ruled out. Twelve of these subjects with persistent symptoms entered the case-control study, as did a matched control group. INTERVENTIONS--Four days of monitoring blood glucose concentrations at home, six daily samples being taken in fixed relation to meals by the finger prick method. Extra samples were taken when symptoms occurred. MAIN OUTCOME MEASURES--Blood glucose concentration, glycated haemoglobin concentration, and within subject variation in measured values. RESULTS--After one to three years of observation 19 of the 21 subjects still had symptoms. Six out of 12 subjects experienced hypoglycaemic symptoms during the controlled study. Blood glucose concentration ranged from 3.7 mmol/l to 7.5 mmol/l during these episodes. Changes in blood glucose concentration, mean blood glucose concentrations at each time point, within subject variation in the measured values, and glycated haemoglobin concentration were not significantly different in all patients compared with the control subjects and in patients with symptoms during the study compared with controls. CONCLUSION--Hypoglycaemic symptoms during everyday life in apparently healthy subjects are persistent but are not related to chemical hypoglycaemia.