Hyperglycemia and RBCs: too sweet to survive

Impact of vitamin D deficiency on iron status in children with type I diabetes

Vitamin D deficiency (VDD) and anemia are both public health nutrition concerns. An association between VDD and anemia has been suggested in various healthy and diseased populations. The current study aimed to elucidate the effect of VDD on iron status in children with type I diabetes mellitus (T1DM). The study recruited two groups of children with T1DM: control group comprised of 38 T1DM children with sufficient vitamin D (> 30 ng/ml) and a case group, consisted of 52 T1DM children with VDD (< 20 ng/ml). Both groups had comparable gender, age, BMI, and disease duration. The laboratory measurements included analysis of blood indices, markers of iron metabolism, hepcidin and inflammatory markers included interleukin 6 (IL-6) and C-reactive protein (CRP). Compared to control group, T1DM children with VDD differs specifically in terms of some markers of blood indices, such as decreased hemoglobin and increased red blood cell distribution width. Moreover, decreased serum iron, ferritin, total iron-binding capacity and transferrin along with elevated inflammatory markers were observed in case group. Results of the study indicated that VDD had increased the risk of iron deficiency anemia in children with T1DM as well as inflammatory related anemia. Furthermore, in T1DM children, VDD had raised the incidence of both absolute and functional iron deficiency, with greater incidence of the former. This study may indicate that VDD may be a risk factor that may worsen iron deficiency anemia in T1DM.

High glucose microenvironment and human mesenchymal stem cell behavior

High glucose (HG) culture conditions in vitro and persistent exposure to hyperglycemia in diabetes patients are detrimental to stem cells, analogous to any other cell type in our body. It interferes with diverse signaling pathways, i.e. mammalian target of rapamycin (mTOR)-phosphoinositide 3-kinase (PI3K)-Akt signaling, to impact physiological cellular functions, leading to low cell survival and higher cell apoptosis rates. While elucidating the underlying mechanism responsible for the apoptosis of adipose tissue-derived mesenchymal stem cells (MSCs), a recent study has shown that HG culture conditions dysregulate mTOR-PI3K-Akt signaling in addition to mitochondrial malfunctioning due to defective mitochondrial membrane potential (MtMP) that lowers ATP production. This organelle-level dysfunction energy-starves the cells and increases oxidative stress and ultrastructural abnormalities. Disruption of the mitochondrial electron transport chain produces an altered mitochondrial NAD+/NADH redox state as evidenced by a low NAD+/NADH ratio that primarily contributes to the reduced cell survival in HG. Some previous studies have also reported altered mitochondrial membrane polarity (causing hyperpolarization) and reduced mitochondrial cell mass, leading to perturbed mitochondrial homeostasis. The hostile microenvironment created by HG exposure creates structural and functional changes in the mitochondria, altering their bioenergetics and reducing their capacity to produce ATP. These are significant data, as MSCs are extensively studied for tissue regeneration and restoring their normal functioning in cell-based therapy. Therefore, MSCs from hyperglycemic donors should be cautiously used in clinical settings for cell-based therapy due to concerns of their poor survival rates and increased rates of post engraftment proliferation. As hyperglycemia alters the bioenergetics of donor MSCs, rectifying the loss of MtMP may be an excellent target for future research to restore the normal functioning of MSCs in hyperglycemic patients.

Red blood cells as biomarkers and mediators in complications of diabetes mellitus: A review

Red blood cells (RBCs), traditionally recognized for their oxygen transport role, have garnered increasing attention for their significance as crucial contributors to the pathophysiology of diabetes mellitus. In this comprehensive review, we elucidate the multifaceted roles of RBCs as both biomarkers and mediators in diabetes mellitus. Amidst the intricate interplay of altered metabolic pathways and the diabetic milieu, RBCs manifest distinct alterations in their structure, function, and lifespan. The chronic exposure to hyperglycemia induces oxidative stress, leading to modifications in RBC physiology and membrane integrity. These modifications, including glycation of hemoglobin (HbA1c), establish RBCs as invaluable biomarkers for assessing glycemic control over extended periods. Moreover, RBCs serve as mediators in the progression of diabetic complications. Their involvement in vascular dysfunction, hemorheological changes, and inflammatory pathways contributes significantly to diabetic microangiopathy and associated complications. Exploring the therapeutic implications, this review addresses potential interventions targeting RBC abnormalities to ameliorate diabetic complications. In conclusion, comprehending the nuanced roles of RBCs as biomarkers and mediators in diabetes mellitus offers promising avenues for enhanced diagnostic precision, therapeutic interventions, and improved patient outcomes. This review consolidates the current understanding and emphasizes the imperative need for further research to harness the full potential of RBC-related insights in the realm of diabetes mellitus.

Application of atomic force microscopy to assess erythrocytes morphology in early stages of diabetes. A pilot study

The study aim was to assess the application of atomic force microscopy (AFM) to evaluate erythrocyte morphology in early stages of type 2 diabetes mellitus, and the association with biochemical, anthropometric, diet, and physical activity indicators. This was a pilot cross-sectional study with four groups: healthy individuals, people with prediabetes (PDG), metabolic syndrome (MSG), and diabetes mellitus group (DMG). Blood samples were obtained to assess the erythrocyte morphology and biochemical parameters. Anthropometrical measurements were taken. Besides, a diet and a physical activity questionnaire were applied. The evaluation of the erythrocyte morphology through the AFM showed quantitative and qualitative alterations in the cell's form and size. Compared to the healthy group, the PDG had a reduction in height (-0.80 μm, p < 0.05), and an increase in axial ratio (-0.09 μm, p < 0.05); the MSG had lower concave depth (-0.19 μm, p < 0.05); and the DMG had a decreased height (-0.46 μm, p < 0.05) and concave depth (-0.29 μm, p < 0.05), and higher axial ratio (+0.08 μm) and thickness (+0.32 μm, p < 0.05). The PDG vs. DMG had a statistically significant difference in concave depth (+0.23 μm, p < 0.05) and thickness (-0.26 μm, p < 0.05). The MSG was different than the DMG in variables like axial ratio (-0.05 μm) and thickness (-0.25 μm). Besides, higher values of age, HbA1c, triglycerides, body mass index, waist-to-hip ratio, and physical inactivity were associated with altered erythrocyte morphology. AFM is a promising instrument to assess early but subtle changes in erythrocyte morphology (height, axial ratio, concave depth, thickness) before significant pathological conditions, such as type 2 diabetes mellitus. HbA1c might have a major effect in altered morphology, vs. metabolic parameters like high triglycerides, body mass index, waist, and physical inactivity.