The influence of GGT, COHb% and body weight on the 2-h glucose and insulin response after a standardized oral glucose load.

Relative body weight (A/I weight) serum gamma-glutamyl-transferase (GGT) and carboxyhemoglobin (COHb%) were related to glucose and insulin values at 0 and 120 min in a sizable, consecutive series of oral glucose tolerance tests (OGTTs) in middle-aged males. Partial and multiple correlation coefficients were calculated, and the squared stepwise multiple correlation coefficient was used to estimate how much of the variability of glucose and insulin could be accounted for by the three factors. No less than 14% of the glucose variability and 25% of the insulin variability at 2 h could be attributed to them, emphasizing the importance of keeping these three factors in mind when interpreting the results of OGTTs.