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

Abstract

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.

Keywords: Erythrocytes; Glycated hemoglobin; Hyperglycemia; Inflammation; Iron deficiency; Obesity; Osmotic stability; RDW.