Because of the demonstration of a genetic linkage between glucokinase
and Type II diabetes, and the central role of glucokinase on glucose m
etabolism, we studied glucokinase activity in the liver of patients wi
th and without Type II diabetes. Glucokinase activity was decreased by
about 50% in obese subjects with diabetes (n = 12) compared with (p<0
.01) lean controls (n = 9) and (p < 0.05) obese controls (n = 10). The
re was no difference between lean and obese controls. Fifty percent of
subjects with diabetes had lower liver glucokinase activity than the
lowest value of the controls. These data further support the important
role that glucokinase plays in the pathogenesis of Type II diabetes.