Abstract: Oral glucose tolerance test（OGTT）was performed in 202 healthy adults.For each of them,plasma glucose was determined first in an overnight-fast state and then serially following a standard 100 gm glucose load.No significant difference was noted in the fasting glucose level with regard to sex or body weight.However,following glucose load,the glucose levels were higher in obese subjects（39）than in those with normal body weight（163）.Plasma glucose levels in females（89）showed a delay in return to normal when compared with that in males（113）.Furthermore,when all the glucose levels were collectively considered,an increase in glucose value was apparent with advancing age,regardless of sex.
Thus,in evaluation of an OGTT,all the above-mentioned factors should be taken into consideration.Otherwise,an over-diagnosis of abnormal tests will be made.In view of the finding that the value of plasma glucose is higher in older persons,the upper limit of normal should vary directly with increase in age.We therefore suggest that for patients of 50-59 age group,a fasting value＞110 mg/dl or a 2° value≥180mg/dl should be considered as the criteria for the diagnosis of diabetes mellitus.For subjects over 59 years in age,it seems appropriate to add 2 mg/dl/decade to the fasting plasma value and 10 mg/dl/decade to the fasting plasma value,and 10mg/dl/decade to the postoral-glucose plasma values.