Inflammatory Markers in Pediatric Obesity: Health and Physical Activity Implications

The prevalence of childhood obesity has recently peaked in the USA with ~17% of children considered obese. With the increase in adiposity that occurs with weight gain, a persistent low-grade inflammatory state is created. The most commonly studied inflammatory markers associated with obesity are the cytokines, tumor necrosis factor α and interleukin-6, and the acute-phase reactant, C-reactive protein. Understanding the relation between adiposity and inflammation is an important concept because these inflammatory markers influence insulin sensitivity, glucose metabolism, and atherosclerosis, ultimately leading to impaired health. In addition to obesity, physical inactivity is associated with elevated inflammatory markers. The literature, however, is inconsistent as to whether the association between physical activity and inflammation is independent of adiposity. In some obese children, physical fitness appears to circumvent the increase in inflammatory markers that are associated with obesity. The purpose of this review is to examine the relation between adiposity and inflammatory markers, including potential health implications and the impact of physical activity. We exposed a dearth of literature in understanding the interaction between obesity and physical activity on inflammatory markers, especially in children because their anthropometrics change. This review highlights the necessity for further research to better understand the complexity of the chronic inflammatory state associated with obesity

Does Exercise Decrease Pain via Conditioned Pain Modulation in Adolescents?

Purpose: Pain relief after exercise, exercise-induced hypoalgesia (EIH), is established across the lifespan. Conditioned pain modulation (CPM: pain inhibits pain) may be a mechanism for EIH. Methods: In 55 adolescents, pressure pain thresholds were measured before and after exercise (deltoid, quadriceps, and nail bed) and during CPM at the nail bed and deltoid test stimulus sites. The relationship between EIH and CPM was explored. Results: EIH occurred at deltoid and quadriceps; CPM occurred at nail bed and deltoid. CPM and EIH correlated at deltoid; adolescents with greater CPM experienced greater pain relief after exercise. At this site, CPM predicted 5.4% of EIH. Arm lean mass did not add a significant effect. Peak exercise pain did not influence EIH. Adolescents with none, minimal, moderate, or severe peak exercise pain experienced similar EIH. Conclusions: A potential relationship exists between CPM and EIH in adolescents. Pediatric physical therapists should consider the CPM response when prescribing exercise as a pain management tool

Does Weight Status Impact Metabolic Health in Adolescents When Controlling for Physical Fitness?

Purpose: To determines whether adolescents who are fit with overweight/obesity are similar in their metabolic profile to adolescents who are fit and normal weight. Methods: Adolescents participated in 3 sessions: (1) resting vitals and anthropometrics; (2) maximal aerobic treadmill test () to determine physical fitness; and (3) dual-energy x-ray absorptiometry and fasting laboratory draw for analysis of insulin, glucose, high-density lipoprotein, triglycerides, and C-reactive protein. Results: Of the 30 fit adolescents who are normal weight and 16 adolescents who are fit and overweight/obese (OW/OB), metabolic syndrome was apparent in 1 adolescent who are normal weight and 4 adolescents who are OW/OB. Metabolic syndrome severity was positively associated with body mass index, waist circumference, total body fat, insulin resistance, and C-reactive protein but inversely associated with peak relative, but not lean . Conclusions: Despite good physical fitness, adolescents who are OW/OB demonstrated greater metabolic syndrome than adolescents who are normal weight. Future intervention research is necessary to explore the relation between physical fitness and metabolic syndrome

Pain Response after Maximal Aerobic Exercise in Adolescents across Weight Status

Introduction Pain reports are greater with increasing weight status, and exercise can reduce pain perception. It is unknown, however, whether exercise can relieve pain in adolescents of varying weight status. The purpose of this study was to determine whether adolescents across weight status report pain relief after high-intensity aerobic exercise (exercise-induced hypoalgesia (EIH)). Methods Sixty-two adolescents (15.1 ± 1.8 yr, 29 males) participated in the following three sessions: 1) pressure pain thresholds (PPT) before and after quiet rest, clinical pain (McGill Pain Questionnaire), and physical activity levels (self-report and ActiSleep Plus Monitors) were measured, 2) PPT were measured with a computerized algometer at the fourth finger’s nailbed, middle deltoid muscle, and quadriceps muscle before and after maximal oxygen uptake test (V˙O2max Bruce Treadmill Protocol), and 3) body composition was measured with dual-energy x-ray absorptiometry. Results All adolescents met criteria for V˙O2max. On the basis of body mass index z-score, adolescents were categorized as having normal weight (n = 33) or being overweight/obese (n = 29). PPT increased after exercise (EIH) and were unchanged with quiet rest (trial × session, P = 0.02). EIH was similar across the three sites and between normal-weight and overweight/obese adolescents. Physical activity and clinical pain were not correlated with EIH. Overweight/obese adolescents had similar absolute V˙O2max (L·min−1) but lower relative V˙O2max (mL·kg−1·min−1) compared with normal-weight adolescents. When adolescents were categorized using FitnessGram standards as unfit (n = 15) and fit (n = 46), the EIH response was similar between fitness levels. Conclusions This study is the first to establish that both overweight and normal-weight adolescents experience EIH. EIH after high-intensity aerobic exercise was robust in adolescents regardless of weight status and not influenced by physical fitness

The Role of Aerobic Physical Fitness in Overweight Adolescents

Photograph of H. and J. Shaw's Lang Wheels Jets J10 Centre Truck taken at Forest site, 29 September 1958 whole side view

Inflammatory markers, physical fitness, and pain in children

The current pediatric obesity epidemic is associated with increased clinical pain; the relation between pain and obesity is not clear but a potential mechanism is inflammation. Obesity is a chronic pro-inflammatory state associated with risk for metabolic syndrome, diabetes and cardiovascular disease. Furthermore, inflammatory markers contribute to the development and modulation of pain. Exercise, a hallmark of obesity interventions, is often prescribed for pain management. Pain relief after exercise, exercise induced hypoalgesia (EIH), may be a critical pain management strategy for overweight/obese adolescents, but it is unknown if EIH exists in adolescents. Moreover, mechanisms for EIH are not established; the concept of conditioned pain modulation (CPM), ‘pain inhibits pain,’ is a possible central component of pain relief after exercise through endogenous pain inhibition. In adolescents across weight status, experimental pain was assessed at baseline, in a CPM protocol, and pre/post maximal aerobic exercise (EIH). Clinical pain, psychosocial parameters, physical fitness, physical activity levels, body composition, and health status were also measured. In this community sample, normal weight and overweight/obese adolescents did not report clinically significant differences in clinical/experimental pain. Adolescents with higher BMI and central adiposity demonstrated elevated inflammation and metabolic syndrome severity but decreased quality of life. Fit overweight/obese adolescents demonstrated higher quality of life and decreased metabolic syndrome severity but similar inflammation and pain. Adolescents experienced EIH regardless of weight status, physical activity, and physical fitness; EIH was positively associated with lean mass. CPM was similar between weight status and sex; lean mass uniquely predicted the CPM magnitude. CPM and EIH are mildly associated but further pediatric research is warranted. These results suggest that adolescents of overweight/obese status experienced increased metabolic syndrome severity but not necessarily clinical pain; physical fitness circumvented metabolic syndrome severity. Aerobic exercise may be utilized for pain relief in adolescents across weight status. Endogenous pain modulation may be a possible mechanism of pain relief after exercise, but pain with exercise is not required for pain relief after exercise. Assessment of EIH and CPM in pediatric populations may help guide and tailor unique interventions to assist with pain management across the weight spectrum