Abstract
The P50 of the oxyhemoglobin dissociation curve (ODC) was determined in 204 treated diabetic patients with and without retinopathy and in 24 non-diabetic and non-smoking healthy volunteers. None of the patients were acidotic. The 204 patients were divided into 4 groups as follows:
47 diabetics designated group 1 and having no retinopathy.
51 diabetics designated group 2 and having non-proliferative retinopathy.
53 diabetics designated group 3 and having pre-proliferative retinopathy.
53 diabetics designated group 4 and having proliferative retinopathy.
Each of the four groups was divided again into two subgroups by hemoglobin concentration (below 13 g/dl and above 13 /dl) or HbAi (below 9 % and above 9 %).
RESULTS:
I. P50 in vivo pH and P50 pH 7.4 were not significantly different among all diabetic groups from 1 to 4 compared with the normal control group.
II. The 2, 3-DPG concentration was significantly higher in individuals having below 13 g/dl of hemoglobin than in those having above 13g/dl of hemoglobin in all subgroups, but P50 was not significant in any of the subgroups.
III. The 2, 3-DPG concentration was higher in individuals having above 9 % of HbAi than in those having below 9% of HbAi in groups 3 and 4. However only group 3 was statistically significant. There was no difference in P50 among all groups.
IV. In groups 3 and 4 the correlation between P50 pH 7.4 and 2, 3-DPG was calculated for groups having a combination of hemoglobin less than 13 01/ and HbA1 greater than 9 % and for the groups having a combination of hemoglobin greater than 13 g/dl and HbA1 less than 9%. There was no correlation between the 2, 3-DPG and P50 pH 7.4 in patients of group 4 having both hemoglobin below 13 g/dl and HbAi above 9 %.
We conclude that in group 4, consisting of diabetic patients with proliferative retinopathy showing less than 13 g/dl hemoglobin and more than 9 % HbAi, the 2, 3-DPG concentration may affect the ODC as only a slight possibility of a shift to the right.
