Core Laboratory
12. FSIGT
The laboratory provides an integrated service to assess insulin sensitivity using the frequently sampled intravenous glucose tolerance test (FSIGT). Insulin and glucose concentrations complete with computer analysis and determination of SI and SG are provided.
The frequently sampled intravenous glucose tolerance test consists of fasting baseline blood samples at -20 min, -10 min and -5 min followed by an intravenous bolus of 50% glucose (0.3 g/kg body weight) at time = 0 following which blood samples are drawn from an indwelling catheter for glucose and insulin determinations at times 2, 3, 4, 6, 8, 10, 12, 14, 16 and 19 minutes. At 20 minutes a bolus of insulin is administered (0.05 U/kg body weight) and further samples drawn at 22, 23, 24, 25, 30, 40, 50, 60, 70, 80, 100, 120, 140, 160, 180, 200, 220 and 240 minutes. Many subjects with impaired glucose tolerance and most with overt diabetes will have a suboptimal insulin response to glucose. The glucose and insulin values are analysed by a computer model developed by Dr. Richard Bergman (UCLA) to yield values for glucose effectiveness (SG) and insulin sensitivity index (SI).
References:
- Bergman R, Ider YZ, Bowden C, Cobelli C. Quantitative estimation of insulin sensitivity. Amer J Physiol 236: E667-E677, 1979.
- Toffolo G, Bergman R, Finegood D, Bowden C, Cobelli C. Quantitative estimation of b-cell sensitivity to glucose in the intact organism. Diabetes 29: 979-90, 1980.
For more information, please contact the Core Laboratory manager or director.