Inflammatory cytokine, growth factor and counterregulatory responses to exercise in children with type 1 diabetes and healthy controls

Abstract

In children with type 1 diabetes (T1DM), altered adaptive responses to exercise (secretion of growth factors, inflammatory cytokines, and glucoregulatory mediators) may have potential implications in growth and development, early onset of disease complications, and incidence of hypoglycemia. We therefore measured a broad spectrum of exercise responses in 12 children with T1DM (seven males and five females) and 12 controls (six males / six females) aged 11-15 yr, during a 30-min exercise challenge @ 80% VO(2)max. Euglycemia was strictly controlled during exercise, and in diabetic patients a basal rate of i.v. insulin was allowed to maintain baseline insulin concentrations. Throughout the experiment, interleukin-6 (IL-6) concentrations (pg/mL) were markedly higher in T1DM vs. controls (preexercise: 5.0+/-1.3 vs. 1.9+/-0.6, p<0.02; end-exercise 5.3+/-1.2 vs. 2.7+/-1.0, p<0.05; 30-min postexercise: 8.2+/-2.2 vs. 3.9+/-0.8, p<0.05). A similar pattern was also observed with norepinephrine. Growth hormone (GH) concentration was similar in both groups at baseline and end-exercise, but in T1DM the exercise-induced GH remained significantly elevated 30 min after exercise (9.2+/-2.2 vs. 3.1+/-0.9 ng/L, p<0.01). The exercise-induced increase in glucagon elicited by exercise in controls was similar to that previously observed in healthy adults (10+/-3 pg/mL); however, it was significantly blunted in T1DM children (2+/-2 pg/mL, p<0.05). In conclusion, T1DM children displayed significant alterations in multiple aspects of their adaptive response to intense exercise.

Effect of prior hyperglycemia on IL-6 responses to exercise in children with type 1 diabetes

“…At the time of disease onset, IL-6 has been identified as a major contributor to the autoimmune process leading to ␤-cell destruction in animal models of T1DM (22). It remains somewhat unclear, however, whether elevated IL-6 is only present during the early stages of the disease, or if these elevations are permanent, as some, but not all reports in diabetic patients indicate a high concentration of baseline, resting IL-6 (13,17,32). Our results may provide a possible explanation for this discrepancy, as high or normal IL-6 concentrations may have been the reflection of the particular metabolic status, including prior glycemic fluctuations, of study participants at the time of sampling, rather than an intrinsic effect of diabetes per se.…”

Endocrine Responses to Exercise in the Developing Child and Adolescent

“…Both studies included children with a wide age range and showed that cortisol concentrations were lower in the recovery period 1 h after exercise compared to concentrations at baseline and immediately after exercise [4,29] . Salivary cortisol measurements in adolescent female tennis players after 16 weeks of training also showed a low overall output of salivary cortisol and a blunted response to awakening [30] .…”

Effect of intermittent high intensity exercise on counter-regulatory hormones in type 1 diabetes glargine/glulisine users

“…Intermittent high intensity exercise reduced the decline in BG during exercise in participants with T1DM [2,6]. Repeated intense sprints interrupting longer periods of moderateintensity exercise is typical of interval training which has gained in popularity for its favorable impact on cardiovascular function [7] and may simulate the type of exercise performed in many sports.…”