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.