Frequency of hypoglycaemia during the intravenous glucose tolerance test in overweight children

The study aimed to assess the frequency of hypoglycaemia during the insulin-modified, frequently sampled intravenous glucose tolerance test (FSIVGTT) in overweight Hispanic children. The study included 210 children, mean age=11±1.7 years, BMI percentile=97.2±2.9 who where enrolled in a longitudinal study to explore risk factors for type 2 diabetes. Two fasting blood samples were collected to determine basal glucose and insulin concentrations. At time 0, glucose (0.3 g/kg body weight) was administered intravenously. Eleven blood samples were collected until 180 min post glucose injection. Insulin (0.02 U/kg body weight) was injected intravenously at 20 min. Plasma was analyzed for glucose and insulin and used for the determination of insulin sensitivity. Hypoglycaemia, defined as a plasma glucose<50 mg/dl, was observed in one asymptomatic subject (<0.5% subjects). In addition, only 1.9% of subjects (n=4) had plasma glucose<60 mg/dl at any time during the FSIVGTT. The frequency of hypoglycaemia during the insulin modified FSIVGTT is very low in overweight Hispanic youth.