Lori D. Wilson

Do circulating leucocytes and lymphocyte subtypes increase in response to brief exercise in children with and without asthma

Background: Exercise can alter health in children in both beneficial (eg reduced long-term risk of atherosclerosis) and adverse (eg exercise-induced asthma) ways. The mechanisms linking exercise and health are not known, but may rest, partly, on the ability of exercise to increase circulating immune cells. Little is known about the effect of brief exercise, more reflective of naturally occurring patterns of physical activity in children, on immune cell responses. Objectives: To determine whether (1) a 6-min bout of exercise can increase circulating inflammatory cells in healthy children and (2) the effect of brief exercise is greater in children with a history of asthma. Methods: Children with mild–moderate persistent asthma and age-matched controls (n = 14 in each group, mean age 13.6 years) performed a 6-min bout of cycle-ergometer exercise. Spirometry was performed at baseline and after exercise. Blood was drawn before and after exercise, leucocytes were quantified and key lymphocyte cell surface markers were assessed by flow cytometry. Results: Exercise decreased spirometry only in children with asthma, but increased (p<0.001) most types of leucocytes (eg lymphocytes (controls, mean (SD) 1210 (208) cells/μl; children with asthma, 1119 (147) cells/μl) and eosinophils (controls, 104 (22) cells/μl; children with asthma, 88 (20) cells/μl)) to the same degree in both groups. Similarly, exercise increased T helper cells (controls, 248 (60) cells/μl; children with asthma, 232 (53) cells/μl) and most other lymphocyte subtypes tested. By contrast, although basophils (16 (5) cells/μl) and CD4+ CD45RO+ RA+ lymphocytes (19 (4) cells/μl) increased in controls, no increase in these cell types was found in children with asthma. Conclusions: Exercise increased many circulating inflammatory cells in both children with asthma and controls. Circulating inflammatory cells did increase in children with asthma, but not to a greater degree than in controls. In fact, basophils and T helper lymphocyte memory transition cells did not increase in children with asthma, whereas they did increase in controls. Even brief exercise in children and adolescents robustly mobilises circulating immune cells.

Effects of exercise on biobehavioral outcomes of fatigue during cancer treatment: results of a feasibility study.

Cancer treatment is associated with decreased hemoglobin (Hb) concentration and aerobic fitness (VO2 max), which may contribute to cancer-related fatigue (CRF) and decreased quality of life (QoL). Endurance exercise may attenuate CRF and improve QoL, but the mechanisms have not been thoroughly investigated. Objectives. To (a) determine the feasibility of conducting an exercise intervention among women receiving treatment for breast cancer; (b) examine the effects of exercise on Hb and VO2 max and determine their association with changes in CRF and QoL; and (c) investigate changes in selected inflammatory markers. Methods. Fourteen women receiving chemotherapy for Stages I–II breast cancer were randomly assigned to exercise (n = 7) or usual care (n = 7). Women in the exercise group performed supervised, individualized treadmill exercise 2–3 times/week for the duration of chemotherapy (9–12 weeks). Data were collected 4 times over 15–16 weeks. Results. Recruitment rate was 45.7%. Sixteen women consented and 14 completed the trial, for a retention rate of 87.5%. Adherence to exercise protocol was 95–97%, and completion of data collection was 87.5–100%. Exercise was well tolerated. VO2 max was maintained at prechemotherapy levels in exercisers but declined in the usual-care group (p < .05). Hb decreased (p < .001) in all participants as they progressed through chemotherapy. Exercise did not have significant effects on CRF or QoL. Changes in inflammatory markers favored the exercise group. Conclusions. Exercise during chemotherapy may protect against chemotherapy-induced decline in VO2 max but not Hb concentration.

Higher IL-6 and IL6:IGF Ratio in Patients with Barth Syndrome

BackgroundBarth Syndrome (BTHS) is a serious X-linked genetic disorder associated with mutations in the tafazzin gene (TAZ, also called G4.5). The multi-system disorder is primarily characterized by the following pathologies: cardiac and skeletal myopathies, neutropenia, growth delay, and exercise intolerance. Although growth anomalies have been widely reported in BTHS, there is a paucity of research on the role of inflammation and the potential link to alterations in growth factors levels in BTHS patients.MethodsPlasma from 36 subjects, 22 patients with Barth Syndrome (0.5 - 24 yrs) and 14 healthy control males (8 - 21 yrs) was analyzed for two growth factors: IGF-1 (bound and free) and Growth Hormone (GH); and two inflammatory cytokines IL-6 and TNF-α using high-sensitivity enzyme-linked immunosorbent assays.ResultsThe average IL-6 and IL6:IGF ratio levels were significantly higher in the BTHS (p = 0.046 and 0.02 respectively). As for GH, there was a significant group by age interaction (p = 0.01), such that GH was lower for BTHS patients under the age of 14.4 years and higher than controls after age 14.4 years. TNF-α levels were not significantly different, however, the TNF-α:GH was lower in BTHS patients than controls (p = 0.01).ConclusionsComparison of two anabolic growth mediators, IGF and GH, and two catabolic cytokines, IL-6 and TNF-α, in BTHS patients and healthy age-matched controls demonstrated a potential imbalance in inflammatory cytokines and anabolic growth factors. Higher rates of IL-6 (all ages) and lower GH levels were observed in BTHS patients (under age 14.5) compared to controls. These findings may implicate inflammatory processes in the catabolic nature of Barth Syndrome pathology as well as provide a link to mitochondrial function. Furthermore, interactions between growth factors, testosterone and inflammatory mediators may explain some of the variability in cardiac and skeletal myopathies seen in Barth Syndrome.

Maximal oxygen uptake at the same fat‐free mass is greater in men than women

Maximal oxygen uptake (V̄O2max) is commonly divided by body mass or fat‐free mass (body mass minus fat mass) in order to make it size independent so that comparisons among persons of different size can be made. However, numerous studies have shown that the ratio created is not size‐independent. Analysis of covariance (ANCOVA) allows a dependent variable to be compared between groups at a common value of a covariate. The purpose of this study was to compare V̄O2max at the same fat‐free mass (FFM) in 230 sedentary subjects (half men) who ranged in age from 20 to 70 years. The subjects underwent maximal cardiopulmonary exercise testing on a cycle ergometer as ventilation and the expired gas fractions were being measured. Two ANCOVA models were evaluated. The dependent variable, fixed factor and covariate(s) in the linear model were V̄O2max, sex and FFM, respectively. The corresponding terms in the log‐linear model were ln V̄O2max, sex, and ln FFM and age. Sex made a significant contribution to both models. In the linear model, the mean V̄O2max at the same FFM was 27% higher in men (2444 versus 1929 ml min−1; P<0·001). In the log‐linear model, the corresponding value at the same FFM and age was 32% higher in men (2368 versus 1794 ml min−1; P<0·001). The goodness of fit indices of squared multiple correlation coefficient and standard error of estimate were significantly better for the log‐linear model. We conclude that V̄O2max at the same FFM is considerably higher in men than in women who have a sedentary lifestyle.