Relationship between GHb concentration and erythrocyte survival determined from breath carbon monoxide concentration.
OBJECTIVE
Subjects with decreased erythrocyte survival have an unusually low GHb percentage. The goal of this study was to determine whether hyperglycemia, as reflected by GHb percentage, is associated with decreased erythrocyte survival.


METHODS
Erythrocyte survival was quantitated in 23 subjects with type 2 diabetes, and these values were correlated with the subjects' GHb percentage. Erythrocyte survival was determined from the difference between the subjects' alveolar carbon monoxide (CO) concentration and atmospheric CO concentration. Reticulocyte counts were obtained in 16 subjects.


RESULTS
Although the vast majority of the subjects had erythrocyte life spans that fell within the normal range (123 +/- 23 days), there was a highly significant inverse correlation (r = -0.66, P < 0.01) between life span and GHb percentage, with an average decline in life span of 6.9 days for each 1% rise in GHb. The reticulocyte count inversely correlated with erythrocyte life span (r = -0.77, P < 0.01).


CONCLUSIONS
Hyperglycemia, as evidenced by high GHb percentage, is associated with an appreciable decrease in erythrocyte life span. Because GHb appears to be formed over the lifetime of the erythrocyte, this decreased erythrocyte survival suggests that high GHb percentages may systematically underestimate the true degree of hyperglycemia.
Virtue
Mark A
MA
Minneapolis Veterans Administration Medical Center, Minneapolis, Minnesota 55417, USA.
Furne
Julie K
JK
Nuttall
Frank Q
FQ
Levitt
Michael D
MD
D000328:Adult; D000368:Aged; D001944:Breath Tests; D002248:Carbon Monoxide; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D004905:Erythrocyte Aging; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D006943:Hyperglycemia / Q000097:blood*; D008875:Middle Aged; D009994:Osmolar Concentration; D017701:Reticulocyte Count
D002248:Carbon Monoxide; D006442:Glycated Hemoglobin