Positive correlation between tumor necrosis factor (TNF)-alfa and cardiorespiratory fitness after six-months of regular aerobic exercise in Peruvian Amerindian women.
Resumen
Aim: To evaluate exercise effects on plasma (p)-levels of tumor necrosis factor (TNF)-?, and interleukin (IL)-6 in Amerindian women. Methods: After 5 years of observation during which p-glucose deteriorated and weight increased, 44 Amerindian women took part in a 6-month exercise programme. P-TNF-? and IL-6 had been measured 5 years earlier, and were reassessed before and after exercise. Results: Cardiorespiratory fitness (CRF, from VO2max of 18.55±3.79 to 20.91±4.61 mL kg-1 min-1;p< 0.0001) and p-TNF-? (from 3.2±3.4 to 4.3±6.6 pg/mL;p=0.0266) increased, whereas p-glucose (from 5.19±1.59 to 4.32±1.62 mmol/L;p<0.0001) and waist circumference (p=0.0128) decreased. Weight, p-insulin, and IL-6 were unchanged. Post-exercise p-glucose (4.16±0.48 mmol/L) and p-TNF-? (4.3±4.6 pg/mL) were identical to values 5 years earlier. P-TNF-? was positively associated with VO2max, prior to (r=.414;p<0.01) as well as after (r=.362;p<0.05) exercise, independently of adiposity. P-IL-6 was associated with waist circumference but not with VO2max. Conclusions:
P-TNF-? correlated with CRF independently of adiposity. Beneficial effects of exercise on p-glucose were simultaneous with increasing p-TNF-?. While p-glucose had deteriorated and weight increased during the previous 5 years, p-TNF-? had decreased. Exercise restored p-TNF-? to baseline levels without weight change. Our findings are inconsistent with literature as TNF-? has been considered to contribute to insulin resistance.
