Exercise leukocyte profiles in healthy, type 1 diabetic, overweight, and asthmatic children

Cardiorespiratory Fitness and Physical Activity in Pediatric Diabetes: A Systemic Review and Meta-Analysis

Importance

It is unclear whether cardiorespiratory fitness (CRF) and physical activity are lower among youths with type 1 diabetes (T1D) and type 2 diabetes (T2D) compared with youths without diabetes.

Objective

To describe the magnitude, precision, and constancy of the differences in CRF and physical activity among youths with and without diabetes.

Data Sources

MEDLINE, Embase, CINAHL, and SPORTDiscus were searched from January 1, 2000, to May 1, 2022, for eligible studies.

Study Selection

Observational studies with measures of CRF and physical activity in children and adolescents aged 18 years or younger with T1D or T2D and a control group were included.

Data Extraction and Synthesis

Data extraction was completed by 2 independent reviewers. A random-effects meta-analysis model was used to estimate differences in main outcomes. The pooled effect estimate was measured as standardized mean differences (SMDs) with 95% CIs. The Preferred Reporting Items for Systematic Review and Meta-Analyses guideline was followed.

Main Outcomes and Measures

The main outcomes were objectively measured CRF obtained from a graded maximal exercise test and subjective or objective measures of physical activity. Subgroup analyses were performed for weight status and measurement type for outcome measures.

Results

Of 7857 unique citations retrieved, 9 studies (755 participants) with measures of CRF and 9 studies (1233 participants) with measures of physical activity for youths with T2D were included; for youths with T1D, 23 studies with measures of CRF (2082 participants) and 36 studies with measures of PA (12 196 participants) were included. Random-effects models revealed that directly measured CRF was lower in youths with T2D (SMD, -1.06; 95% CI, -1.57 to -0.56; I2 = 84%; 9 studies; 755 participants) and in youths with T1D (SMD, -0.39; 95% CI, -0.70 to -0.09; I2 = 89%; 22 studies; 2082 participants) compared with controls. Random-effects models revealed that daily physical activity was marginally lower in youths with T1D (SMD, -0.29; 95% CI, -0.46 to -0.11; I2 = 89%; 31 studies; 12 196 participants) but not different among youths with T2D (SMD, -0.56; 95% CI, -1.28 to 0.16; I2 = 91%; 9 studies; 1233 participants) compared with controls. When analyses were restricted to studies with objective measures, physical activity was significantly lower in youths with T2D (SMD, -0.71; 95% CI, -1.36 to -0.05; I2 = 23%; 3 studies; 332 participants) and T1D (SMD, -0.67; 95% CI, -1.17 to -0.17; I2 = 93%; 12 studies; 1357 participants) compared with controls.

Conclusions and Relevance

These findings suggest that deficits in CRF may be larger and more consistent in youths with T2D compared with youths with T1D, suggesting an increased risk for cardiovascular disease-related morbidity in adolescents with diabetes, particularly among those with T2D. The findings reinforce calls for novel interventions to empower youths living with diabetes to engage in regular physical activity and increase their CRF.

Childhood asthma and physical activity: a systematic review with meta-analysis and Graphic Appraisal Tool for Epidemiology assessment

BACKGROUND

Childhood asthma is a global problem affecting the respiratory health of children. Physical activity (PA) plays a role in the relationship between asthma and respiratory health. We hypothesized that a low level of PA would be associated with asthma in children and adolescents. The objectives of our study were to (1) summarize the evidence available on associations between PA and asthma prevalence in children and adolescents and (2) assess the role of PA in new-onset or incident asthma among children and adolescents.

METHODS

We searched Medline, the Cochrane Library, and Embase and extracted data from original articles that met the inclusion criteria. Summary odds ratios (ORs) and confidence intervals (CIs) were used to express the results of the meta-analysis (forest plot). We explored heterogeneity using funnel plots and the Graphic Appraisal Tool for Epidemiology (GATE).

RESULTS

We retrieved 1,571 titles and selected 11 articles describing three cohort and eight cross-sectional studies for inclusion. A meta-analysis of the cohort studies revealed a risk of new-onset asthma in children with low PA (OR [95 % CI] 1.32 [0.95; 1.84] [random effects] and 1.35 [1.13; 1.62] [fixed effects]). Three cross-sectional studies identified significant positive associations between childhood asthma or asthma symptoms and low PA.

CONCLUSIONS

Children and adolescents with low PA levels had an increased risk of new-onset asthma, and some had a higher risk of current asthma/or wheezing; however, there was some heterogeneity among the studies. This review reveals a critical need for future longitudinal assessments of low PA, its mechanisms, and its implications for incident asthma in children. The systematic review was prospectively registered at PROSPERO (registration number: CRD42014013761; available at: http://www.crd.york.ac.uk/PROSPERO [accessed: 24 March 2016]).

Aspects of inflammation and oxidative stress in pediatric obesity and type 1 diabetes: an overview of ten years of studies

Obesity and type 1 diabetes (T1DM) are the two most common conditions of altered metabolism in children and adolescents. In both, similar long-term cardiovascular complications are known to occur, mediated in large part by underlying inflammatory and oxidative processes whose biochemical details remain relatively unclear. Through a series of experiments in these patient populations, over the last decade our laboratory has clarified a number of key issues in this field. Interestingly, while obese and type 1 diabetic children often differed in the specific type and magnitude of molecular alterations, in both groups a clear exaggeration of inflammatory and oxidative activation was detected when compared to healthy, age-matched controls. Our main findings include definition of resting and exercise-induced cytokine patterns and leukocyte profiles, patterns of activation of immune cells in vitro, and correlation of the magnitude of observed alterations with severity of obesity and quality of glycemic control. Further, we have identified a series of alterations in growth factor profiles during exercise that parallel inflammatory changes in obese children. This paper offers a concise overview of the salient results from this decade-long research effort.

Inflammatory cytokine profiles during exercise in obese, diabetic, and healthy children

OBJECTIVE

Modulation of inflammatory status is considered a key component of the overall health effects of exercise. This may be especially relevant in children with obesity (Ob) or type 1 diabetes (T1DM), in which an imbalance between pro- and anti-inflammatory mediators could accelerate onset and progression of cardiovascular complications. To date, exercise-induced alterations in immuno-modulatory mediators in Ob and T1DM children remain largely unknown.

METHODS

In this study, we monitored the kinetic profiles of 8 pro-and anti-inflammatory cytokines (TNF-a, IL-6, IL-2, IL-8, IL-5, IL-13, IL-10, IL-4) during a standardized exercise challenge (ten 2-min cycling bouts at 80% VO2max, separated by 1-min intervals) in 23 Ob (12 females, 11 males), 23 T1DM (10 females and 13 males) patients and 20 healthy (CL, 10 females and 10 males) children. Blood glucose of T1DM patients was kept in the 4.4-6.1 mM range for at least 90 minute prior to and during exercise. Blood samples were drawn at rest and after every other exercise bout.

RESULTS

In Ob, TNF-a and IL-2 were significantly greater (p<0.0167) as compared to T1DM and CL, both at baseline and throughout exercise. All other variables, while not significant, were quantitatively elevated in Ob vs. CL. In T1DM, IL-4 and IL-8 levels were similar to Ob, IL-2 and TNF-a similar to CL, and IL-6, IL-5, IL-13, IL-4 levels were intermediate between the Ob and CL groups.

CONCLUSIONS

During exercise, therefore, both Ob and T1DM children displayed exaggerated pro-inflammatory responses, although with clearly different magnitude and involved mediators. Our data support the necessity to identify specific exercise formats through which each at-risk pediatric population can draw maximal beneficial health effects.

Altered inflammatory, oxidative, and metabolic responses to exercise in pediatric obesity and type 1 diabetes

Obesity (Ob) and type 1 diabetes (T1DM) are associated with increased inflammation and oxidative stress, which are major pathogenetic pathways toward higher cardiovascular risks. Although long-term exercise protects against systemic inflammation and oxidation, acute exercise actually exerts pro-inflammatory and oxidative effects, prompting the necessity for better defining these molecular processes in at-risk patients; in particular, very little is known regarding obese and T1DM children. We therefore examined key inflammatory and oxidative stress variables during exercise in 138 peripubertal children (47 Ob, 12.7 ± 0.4 yr, 22 F, BMI% 97.6 ± 0.2; 49 T1DM, 13.9 ± 0.2 yr, 20 F, body mass index% [BMI] 63.0 ± 3.6; 42 healthy, CL, 13.5 ± 0.5 yr, 24 F, BMI% 57.0 ± 3.6), who performed 10 bouts of 2-min cycling ~80% VO(2max) , separated by 1-min rest intervals. Blood samples were drawn at baseline and peak exercise. Ob displayed elevated baseline interleukin-6 (IL-6, 2.1 ± 0.2 pg/mL, p < 0.005) vs. CL (1.5 ± 0.3), whereas T1DM displayed the greatest maximum exercise-induced change in IL-6 (1.2 ± 0.3) than in both Ob (0.7 ± 0.1, p < 0.001) and CL (0.6 ± 0.1, p < 0.0167). Myeloperoxidase (MPO) was elevated in T1DM (143 ± 30 ng/mL, p < 0.0167) vs. CL (89 ± 10) and Ob (76 ± 6), whereas increases in exercise only occurred in Ob and CL. Disparate baseline and exercise responses were also observed for 8-hydroxy-2'-deoxyguanosine, glutathione, and F(2) -isoprostane. This data show distinct patterns of dysregulation in baseline and adaptive immunologic and oxidative responses to exercise in Ob and T1DM. A full understanding of these alterations is required so that developing exercise regimens aimed at maximizing health benefits for specific dysmetabolic states can be achieved based on complete scientific characterization rather than empirical implementation.

Resting and exercise-induced IL-6 levels in children with Type 1 diabetes reflect hyperglycemic profiles during the previous 3 days

Poor glycemic control in Type 1 diabetes (T1DM) causes long-term cardiovascular complications, at least in part via chronic, low-grade inflammation associated with recurrent hyperglycemia. While physical activity can reduce both inflammation and cardiovascular risks, the underlying molecular mechanisms remain unclear. This is particularly important for T1DM children, for whom the prevention of long-term cardiovascular complications must include optimization of exercise-related anti-inflammatory strategies. We therefore studied the effect of prior hyperglycemia on resting and exercise-induced inflammatory status (plasma IL-6) in T1DM children. Glycemia was continuously recorded with a continuous glucose monitoring system (CGMS) system for 63 h preceding a 30-min intermittent cycling exercise protocol at approximately 80% peak rate of oxygen uptake (VO2max). Euglycemia (4.4-6.1 mM) was maintained for 90 min before, during, and 30 min after exercise. IL-6 plasma concentration (pg/ml) was measured at baseline, at end exercise, and 30 min postexercise. Subjects were then divided into quartiles based on average glycemia during the CGMS recording. IL-6 levels (pg/ml) were lowest in the quartile with lowest average 3-day glycemia and increased proportionally to greater hyperglycemic exposure; this was observed at baseline (0.86 +/- 0.10, 1.06 +/- 0.16, 1.14 +/- 0.14, 1.20 +/- 0.16), absolute IL-6 change (Delta) at end exercise (0.20 +/- 0.16, 0.32 +/- 0.10, 0.48 +/- 0.09, 0.62 +/- 0.13), and Delta at 30 min postexercise (0.49 +/- 0.13, 0.71 +/- 0.16, 0.89 +/- 0.14, 1.38 +/- 0.33). Therefore, poorly controlled glycemic profile, even in the 63 h preceding an exercise challenge, can alter inflammatory adaptation in T1DM children. Our data underscore the necessity to fully understand all molecular aspects of physical activity to provide the scientific rationale for exercise regimens that will be able to maximize health benefits for T1DM children.