Positive correlation between tumor necrosis factor (TNF)-α and cardiorespiratory fitness after six-months of regular aerobic exercise in Peruvian Amerindian women.

BACKGROUND: Adipose tissue is a source of inflammatory cytokines which may influence insulin action. AIM: To evaluate exercise effects on plasma (p)-levels of tumor necrosis factor (TNF)-α , and interleukin (IL)-6 in Peruvian Amerindian women.
MATERIAL AND METHODS: After five years of observation during which p-glucose deteriorated and weight increased, 44 Peruvian Amerindian women aged 20-59 years took part in a 6-month exercise program. Plasma TNF-α and IL-6 had been measured 5 years earlier, and were reassessed before and after exercise, using ELISA kits. Cardiorespiratory fitness was derived from the results of the twelve minutes' walk and expressed as maximum oxygen uptake (VO(2max)).
RESULTS: After the training program, estimated VO(2max) increased from 18.55 ± 3.79 to 20.91 ± 4.61 mL kg(-1) min(-1) (p < 0.01) and p-TNF-α increased from 3.2 ± 3.4 to 4.3 ± 6.6 pg/mL (p = 0.03). There were reductions in p-glucose from 5.19 ± 1.59 to 4.32 ± 1.62 mmol/L (p < 0.01) and in waist circumference (p=0.01). Weight, p-insulin, and IL-6 did not change. Levels of p-glucose and p-TNF-α observed after the training period were identical to values 5 years earlier. P-TNF-α was positively associated with estimated VO(2max), prior to (r = .414, p < 0.01) as well as after (r = .362, p < 0.05) exercise, independently of adiposity. P-IL-α was associated with waist circumference but not with estimated VO(2max).
CONCLUSIONS: P-TNF-a correlated with estimated VO(2max) independently of adiposity. Beneficial effects of exercise on p-glucose were observed in spite of an increase in p-TNF-α.