Hypercholesterolemia associated with erythrocytes morphology assessed by scanning electron microscopy in metabolically unhealthy individuals with normal-weight and obesity

Aims: To associate hypercholesterolemia and obesity with red blood cell (RBC) morphology as assessed by scanning electron microscopy (SEM) in metabolically healthy and unhealthy adults with normal weight and with obesity. Methods: Cross-sectional study with four groups: metabolically healthy with normal-weight (MHNW, n = 12), metabolically unhealthy with normal-weight (MUNW, n = 5), metabolically healthy with obesity (MHO, n = 4), and metabolically unhealthy with obesity (MUO, n = 6). SEM was used to assess the RBC morphology (diameter, height, and axial ratio, n = 810 cells). SEM images were analyzed using Gwyddion software to measure the RBC morphology parameters. Results: SEM images showed altered RBC morphologies in the MUNW, MHO, and MUO groups. Diameter and axial ratio were statistically different after comparison of MHNW vs. MUNW (+0.41 μm, +0.05 μm); MUNW vs. MHO (−0.70 μm, −0.05 μm); and MHO vs. MUO (+0.38 μm, +0.04 μm), respectively. Hypercholesterolemia was associated with larger and more elongated RBC, while obesity with smaller RBC. Besides, age, HDL, ultra-processed food consumption were associated with altered RBC morphology. Conclusions: SEM is an excellent instrument to assess qualitatively and quantitatively RBC morphology. Hypercholesterolemia and obesity had a negative effect on the RBC morphology, but producing different effects on the RBC morphology (larger and smaller RBC, respectively).