[The reference value of plasma glucose in individuals over 65 years]

The characteristics of plasma glucose in individuals aged over 65 years was investigated by analysis of age dependent changes of fasting and post glucose (75 g) load values in population based studies and some follow-up studies. Institutional differences were surveyed in central laboratory of institutions which joined this study and found that differences were the range of +3.0-3.5% from the mean glucose levels between 100-400 mg/dl. Therefore plasma glucose values around cutoff level should be confirmed by repeated determinations for reaching final diagnosis. The reference interval of plasma glucose does not differ in an age-dependent manner. We may use the reference interval proposed by the Committee of Diagnostic Criteria of Diabetes Mellitus of Japan Diabetes Society for adult individuals. Cases of diabetes diagnosed before 65 years old should be judged by the adult criteria. However, those who were not diabetic before age 65 and were found to be hyperglycemic after that age can be diagnosed classifying as follows: (1) Diabetes should be diagnosed in individuals with a fasting plasma glucose of 140 mg/dl or more and 2 hours after glucose (75 g) of 240 mg/dl or more. Those with some symptoms suggesting diabetes and either 140 mg/dl more or fasting or 240 mg/dl or more 2 hours post 75 g glucose load can also be diagnosed as diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)