Abstract Introduction Low-grade chronic inflammation (LGCI), a main contributor to chronic non-communicable diseases, can be counteracted by physical activity (arm-cranking ergometer –ACE- aerobic training), as we demonstrated in individuals with spinal cord injury (SCI) and a low oxygen uptake peak (VO2peak) (1). Nevertheless, Paralympic athletes (PA) with motor impairments also tend to exhibit high levels of inflammatory status – IS- (2). To investigate this apparent discrepancy, we evaluated cardiorespiratory fitness (CRF) and IS in PA with a locomotor impairment determined by different health conditions (HC), such as spinal cord injury (SCI) and amputation (AMP). We hypothesized an inverse relationship between CRF and IS (meaning high CRF and low IS and vice versa). Methods A total of 153 male PA (82 PA with SCI and 71 with other HC, including lower limb AMP, poliomyelitis and cerebral palsy and other HC affecting lower limbs) were recruited from the pre-participation screenings (3) preceding 4 summer and 5 winter Paralympic Games and retrospectively evaluated. PA competed in different sport types (38 in skilled sports -SS, 28 in power sports -PS, 61 in mixed, aerobic-anaerobic metabolism, sports -MS- and 26 in endurance sports -ES), to guarantee a wide range of CRF (3). To estimate IS (4) from blood samples neutrophil (N) and lymphocyte (L) counts were measured and their ratio (NLR) was calculated. A cardiopulmonary ACE incremental maximal exercise test was carried out to measure VO2peak. Spearman correlation was performed to evaluate the relationships among parameters of interest. Results As expected VO2peak (ml·kg-1·min-1) varied among the PA, ranging, as median and ranges, from 23.9, 15.2-39.7, in SS, to 43.1, 27.5-58.1, in ES, while it was equal to 32.4, 17.1-50.8, in PS and 33.3, 16.4-44.7, in MS. A second order polynomial regression analysis revealed a negative correlation between NLR (median values ranged from 1.71 in SS to 1.41 in ES) and VO2peak (y = 2.632 - 0.044x + 0.000 x2). Conclusions We showed an inverse relationship between VO2peak and IS in PA with a locomotor impairment competing in sports with different energy expenditure and intensities. PA competing in SS, who displayed the lowest CRF and the highest IS, should improve their VO2peak through both aerobic and strength training to counteract LGCI.
M Bernardi (Mon,) studied this question.