Red blood cell aggregation and deformability among patients qualified for bariatric surgery.

Background: The study presents red blood cell (RBC) aggregability and deformability among obese patients qualified for bariatric surgery and its correlation with plasma lipid concentration.

Methods: We studied 40 morbidly obese patients who were qualified for bariatric surgery: mean age was 43.5 +/- 11.3 years, and mean body mass index (BMI) was 48.9 +/- 7.7 kg/m2. The RBC deformability and aggregation parameters: aggregation index (AI), syllectogram amplitude (AMP) and aggregation half-time (t1/2) were measured by Laser-assisted Optical Rotational Cell Analyser - LORCA.

Results: Elongation index of RBC was significantly lower in obese patients than in the control group (P<0.001) in 3.16-60.03 Pa shear stresses. Correlations between elongation index and triglyceride levels ranged between 0.42 to 0.44 (P<0.05). AI was significantly higher in the obese patients (P<0.001), t1/2 and the AMP were decreased (P<0.001) compared to the control group. The RBC aggregation index correlated positively with total cholesterol level (r = 0.61, P<0.05), non-HDL cholesterol level (r = 0.54, P<0.05) and BMI (r = 0.48, P<0.05). Negative correlation presented t1/2 with total cholesterol (r = -0.64, P<0.05), non-HDL cholesterol (r = - 0.51, P<0.05) and BMI (r= -0.59, P<0.05).

Conclusion: Obesity is associated with RBC rheological disturbances expressed by a decrease in RBC deformability, increased total aggregation extent and the alteration of kinetics of RBC aggregation. These results may suggest the necessity of introducing treatment forms to correct erythrocyte rheological properties, which may improve the blood-flow condition in the microcirculation and prevent postoperative complications after bariatric surgery.