as Related to Diabetes and Obesity

2,3-Diphosphoglycerate was determined in the erythro-cytes of 17 diabetic and 18 obese patients. Results for obese subjects were significantly (P <.01) different from those obtained for 21 healthy subjects. Results for obese and diabetic patients also differed significantly (P <.01), but not those for diabetic and healthy subjects. Hemoglobin, hematocrit, or bicarbonate measurements did not differ among the three groups. 2,3-Diphosphoglycerate (2,3-DPG) is apparently the most important regulatory factor in erythrocyte metabolicactivity,asjudged from its close relation to the function of hemoglobin and its concentration in these cells, which is more than three times greater than that of ATP (1). On the other hand, a relation-ship exists between 2,3-DPG and the activity of cer-tain enzymes in a number of hereditary disorders (2, 3). A marked increase in 2,3-DPG has been described in erythrocytes in cases of hypoxia of different causes (4-6) and this increase is thought to be of physiologi-cal importance for the release of oxygen to peripheral tissues. There arecontradictoryreportson 2,3-DPG india-betic patients (7-9)-who, as it is generally known, suffer from severe tissue hypoxia. Moreover, obesity is associated with respiratory insufficiency followed by secondary polycythemia, which is an indication of hypoxia (10-12). These facts have motivated us to measure 2,3-DPG in the erythrocytes of groups of obese and diabetic patients and to compare the re-sults with those found for healthy individuals. Materials and Methods Blood samples were drawn early in the morning from the antecubital vein of fasting individuals and transferredintosiliconizedtubes.In the caseof dia-betic patients, these were drawn before their usual insulin dose. The diabeticpatientswere not obese,had no ke-toacidosis,and did not manifestany signsofcardiac, pulmonary, or renal insufficiency or any other com-plicating disease