Influence of iron metabolism indices on glycated haemoglobin but not glycated albumin levels in premenopausal women

We have recently shown that in premenopausal women without anaemia, glycated haemoglobin (HbA_1C) is inversely associated with mean corpuscular haemoglobin (MCH). Based on the hypothesis that iron deficient state (IDS) due to menstruation may influence erythrocyte metabolism and thereby HbA_1C levels, we examined the relation of iron metabolism indices with HbA_1C in premenopausal women. HbA_1C, serum glycated albumin (GA) and iron metabolism indices were determined in 104 premenopausal women with normal glucose tolerance. Among them, 17 were diagnosed with iron deficiency anaemia (IDA) and 30 with IDS. The other 57 subjects were diagnosed with normal iron state (NIS). HbA_1C levels showed significant inverse association with serum iron, serum transferrin saturation and serum ferritin in 104 study participants. Multivariate regression analysis identified serum ferritin as negatively associated with HbA_1C. These were also observed in 87 premenopausal women without IDA. HbA_1C levels in IDA subjects and in IDS subjects were higher than it in NIS subjects, while GA levels were not different among the three groups of subjects. In conclusions, iron metabolism indices influence HbA_1C levels, but not serum GA levels, in premenopausal women.