1Mervat A Reda, 1Mona LA Zamzam and 2Mervat A Mohamed.
Departments of 1Physical Medicine and Rehabilitation and 2Microbiology and Immunology, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
Recent work has clearly shown that various types of exercise may have potentially considerable effects, both positive and negative, on immune system. The effect of 8 weeks exercise training, either on a bicycle or on a treadmill, on the quantification and phagocytic activity of neutrophils as well as on the serum levels of cortisol and growth hormone (GH) in non- obese and obese healthy subjects was studied. Blood samples were obtained from 30 healthy subjects (20 non- obese, 10 obese) before and 8 weeks after exercise training. None of the studied subjects was under caloric restricted diet during the study. Neutrophil phagocytic function was assessed by cytomorphological method using Candida albicans. Serum levels of cortisol and GH were measured using Enzyme Immunoassay technique. The study revealed a significant increase in the post-exercise band neutrophil count as well as immature/total neutrophil ratio compared to pre -exercise values in all studied groups. A significant increase in the phagocytic index was found after exercise performed by non- obese subjects, whether bicycle or treadmill, whereas a significant increase in the opsonic index was found after exercise performed by obese subjects. All studied groups showed a significant rise in the post-exercise serum level of cortisol and GH compared to the pre-exercise values. Correlation analysis revealed a significant negative correlation between the post-exercise serum GH level and lytic index in non- obese subjects (r = -0.48, P<0.05). A significant positive correlation was found between the post-exercise GH level and the elevation in the segmented neutrophil count (r = 0.87, P<0.05), whereas a significant negative correlation was found between post-exercise serum cortisol level and the band neutrophil count (r = -0.83, P<0.05) in obese subjects. Obese persons showed no change in their body weight after 8 weeks exercise training. It can be concluded that chronic exercise training had a beneficial effect on the innate immunity represented by increase in both count and phagocytic function of neutrophils as well as on the levels of neuroendocrine hormones as cortisol and growth hormone both in obese and non- obese subjects.