Decreased plasma iron levels in women with hyperglycemia are associated with inflammatory status and involve increased HbA1c, osmotic stability, and volume variability of red blood cells.

BACKGROUND AND AIMS: Iron deficiency tendency in individuals with hyperglycemia influences the HbA1c levels' ability to estimate the stationary blood glucose levels. This study investigated the associations of iron status indicators and HbA1c levels with anthropometric, inflammatory, regulatory, metabolic, and hematologic variables in women with hyperglycemia to most widely characterize this iron deficiency tendency. METHODS: A total of 143 volunteers (68 with normoglycemia and 75 with hyperglycemia) participated in this cross-sectional study. Mann-Whitney test was used to compare groups, and the search for associations between pairs of variables used the Spearman correlation method. RESULTS: In women with hyperglycemia, decreased plasma iron level is associated directly with increased HbA1c (p < 0.001), and these changes are both related to C-reactive protein elevation (p = 0.02 and p < 0.05, respectively) and involve decreased mean hemoglobin concentration (p < 0.01 and p < 0.01), which in turn, involves enhanced osmotic stability (dX) (p < 0.05) and volume variability (RDW) (p < 0.0001) of erythrocytes, as well as decreased indirect bilirubin/total bilirubin ratio (p = 0.04). This indirect bilirubin/total bilirubin decrease, which expresses decreased hemoglobin catabolism, does not seem to be solely a process associated with diminished intracellular concentrations of this protein (p = 0.04) since it is associated with CRP elevation (p = 0.03) and reduced LDL cholesterol (p < 0.0001). CONCLUSIONS: In women with hyperglycemia, decreased plasma iron levels were associated with inflammatory status and involved increased HbA1c, osmotic stability, and volume variability of red blood cells.

Red cell distribution width and erythrocyte osmotic stability in type 2 diabetes mellitus.

This study aimed to investigate the relationship between red cell distribution width (RDW) and erythrocyte osmotic stability in non-diabetic and diabetic individuals in both sexes. The study sample (N = 122) was constituted by 53 type 2 diabetics (DM) and 69 non-diabetics (ND), being 21 and 22 men in each group, respectively. The osmotic stability of erythrocytes was obtained by the variation in saline concentration (dX) capable of determining hypoosmotic lysis. Higher RDW values and lower serum iron concentrations were found in the diabetic group when compared to the non-diabetic volunteers. In the group of diabetic women, RDW was positively correlated with the reticulocyte index, and both RDW and dX were negatively correlated with iron, haemoglobin, transferrin saturation index, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration. In all the groups studied, RDW was positively correlated with dX, especially in the diabetic group, where the correlation was the strongest. RDW elevation in both women and men with type 2 diabetes mellitus was associated with decreased serum iron indicators. Furthermore, RDW has a similar meaning to dX, as small erythrocytes have less haemoglobin, resulting in both an increase of RDW and dX.