Rheological blood behavior is not only influenced by cardiovascular risk factors but also by aging itself. Research into 927 healthy Spanish Mediterranean subjects.

It is not well-established whether the alterations that the hemorheological profile undergoes with aging are an effect of concomitant cardiovascular risk factors or are due to age itself. To clarify this issue, we investigated the effect of age on blood rheology in a population of 927 healthy subjects from eastern Spain aged between 16-85 years, divided into four age groups (<30, 30-44, 45-50, ≥60 years) with and without cardiovascular risk factors. We determined blood viscosity, corrected blood viscosity (BVc), plasma viscosity (PV), erythrocyte aggregation (EA), erythrocyte deformability (EEI60) and fibrinogen, along with glucose and plasma lipids. We found that corrected blood viscosity (p = 0.007), plasma viscosity, erythrocyte aggregation, fibrinogen, glucose, and plasma lipids increased with age (p < 0.001). When subjects with cardiovascular risk factors were excluded, the effect of age on blood rheology persisted for all the cited parameters (p < 0.028). EEI60 increased with age (p = 0.033), and it was attributable to a concomitant increase in mean corpuscular volume (p < 0.001). In the Pearson's correlations, age was related to all the parameters analyzed (P < 0.019). The logistic regression analysis revealed that PV ≥1.30 mPa·s, BVc ≥4.90 mPa·s and EA1 ≥8.3 were associated with age ≥60 years (*p = 0.049, *p = 0.013, *p = 0.045, respectively). These results indicate that, although the presence of cardiovascular risk factors influences rheological properties, aging itself is associated with deterioration of rheological blood behavior, mostly related to inflammatory and lipidic changes.