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A 2 year physical activity and dietary intervention attenuates the increase in insulin resistance in a general population of children: the PANIC study.
Lakka, TA, Lintu, N, Väistö, J, Viitasalo, A, Sallinen, T, Haapala, EA, Tompuri, TT, Soininen, S, Karjalainen, P, Schnurr, TM, et al
Diabetologia. 2020;63(11):2270-2281
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The number of children and adolescents with type 2 diabetes and prediabetes has increased over the past decades which is likely due to decreased physical activity, increased sedentary time, unhealthy diet and consequently increased body fat content. Insulin resistance plays an important role in the development of type 2 diabetes. The aim of this 2 year non-randomised, controlled trial was to investigate the long-term effects of a combined physical activity and dietary intervention programme on insulin resistance in a general population of children, most of whom had a normal body weight. Children in the intervention group had six intervention visits which included 30–45 min of physical activity counselling and 30–45 min of dietary counselling for the children and their parents/carers. Fasting insulin and HOMA-IR (a measure for insulin resistance) increased significantly less in the intervention group than in the control group, whilst there were no significant differences in fasting glucose, body fat or lean body mass after 2 years. The effects on insulin resistance were mediated by changes in physical activity, sedentary time and diet. The authors conclude that the prevention of type 2 diabetes should begin in childhood by increasing physical activity, decreasing sedentary time and improving diet in the general paediatric population and not just among overweight and obese children.
Abstract
AIMS/HYPOTHESIS We studied for the first time the long-term effects of a combined physical activity and dietary intervention on insulin resistance and fasting plasma glucose in a general population of predominantly normal-weight children. METHODS We carried out a 2 year non-randomised controlled trial in a population sample of 504 children aged 6-9 years at baseline. The children were allocated to a combined physical activity and dietary intervention group (306 children at baseline, 261 children at 2-year follow-up) or a control group (198 children, 177 children) without blinding. We measured fasting insulin and fasting glucose, calculated HOMA-IR, assessed physical activity and sedentary time by combined heart rate and body movement monitoring, assessed dietary factors by a 4 day food record, used the Finnish Children Healthy Eating Index (FCHEI) as a measure of overall diet quality, and measured body fat percentage (BF%) and lean body mass by dual-energy x-ray absorptiometry. The intervention effects on insulin, glucose and HOMA-IR were analysed using the intention-to-treat principle and linear mixed-effects models after adjustment for sex, age at baseline, and pubertal status at baseline and 2 year follow-up. The measures of physical activity, sedentary time, diet and body composition at baseline and 2 year follow-up were entered one-by-one as covariates into the models to study whether changes in these variables might partly explain the observed intervention effects. RESULTS Compared with the control group, fasting insulin increased 4.65 pmol/l less (absolute change +8.96 vs +13.61 pmol/l) and HOMA-IR increased 0.18 units less (+0.31 vs +0.49 units) over 2 years in the combined physical activity and dietary intervention group. The intervention effects on fasting insulin (regression coefficient β for intervention effect -0.33 [95% CI -0.62, -0.04], p = 0.026) and HOMA-IR (β for intervention effect -0.084 [95% CI -0.156, -0.012], p = 0.023) were statistically significant after adjustment for sex, age at baseline, and pubertal status at baseline and 2 year follow-up. The intervention had no effect on fasting glucose, BF% or lean body mass. Changes in total physical activity energy expenditure, light physical activity, moderate-to-vigorous physical activity, total sedentary time, the reported consumption of high-fat (≥60%) vegetable oil-based spreads, and FCHEI, but not a change in BF% or lean body mass, partly explained the intervention effects on fasting insulin and HOMA-IR. CONCLUSIONS/INTERPRETATION The combined physical activity and dietary intervention attenuated the increase in insulin resistance over 2 years in a general population of predominantly normal-weight children. This beneficial effect was partly mediated by changes in physical activity, sedentary time and diet but not changes in body composition. TRIAL REGISTRATION ClinicalTrials.gov NCT01803776 Graphical abstract.
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Swimming pool exposure is associated with autonomic changes and increased airway reactivity to a beta-2 agonist in school aged children: A cross-sectional survey.
Cavaleiro Rufo, J, Paciência, I, Silva, D, Martins, C, Madureira, J, Oliveira Fernandes, E, Padrão, P, Moreira, P, Delgado, L, Moreira, A
PloS one. 2018;13(3):e0193848
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Studies have shown an association between swimming in chemically-treated pools and a higher risk of asthma in children, although the mechanism is not fully understood. This study aimed to investigate how swimming pool attendance influences lung and nervous system function in school-aged children. Around 800 children were classified as current swimmers (CS), past swimmers (PS) or non-swimmers (NS). The children underwent several tests to determine their lung function and allergic response to common allergens. Parasympathetic nervous system function was tested by measuring the speed at which their pupils constricted in response to light. The current swimmers group had significantly lower pupil constriction speeds compared to PS and NS, suggesting a poorer functioning of the autonomic nervous system, possibly due to inflammation resulting from swimming pool chemical exposure. CS experienced greater constriction of the airways compared to NS. A non-significant trend for a higher risk of asthma, atopic eczema and rhinitis, was observed in swimmers. The authors concluded that swimming pool attendance appears to be associated with autonomic nervous system changes and increased baseline airway smooth muscle constriction even in children without asthma.
Abstract
BACKGROUND Endurance swimming exercises coupled to disinfection by-products exposure has been associated with increased airways dysfunction and neurogenic inflammation in elite swimmers. However, the impact of swimming pool exposure at a recreational level on autonomic activity has never been explored. Therefore, this study aimed to investigate how swimming pool attendance is influencing lung and autonomic function in school-aged children. METHODS A total of 858 children enrolled a cross sectional survey. Spirometry and airway reversibility to beta-2 agonist, skin-prick-tests and exhaled nitric oxide measurements were performed. Pupillometry was used to evaluate autonomic nervous function. Children were classified as current swimmers (CS), past swimmers (PS) and non-swimmers (NS), according to the amount of swimming practice. RESULTS Current swimmers group had significantly lower maximum and average pupil constriction velocities when compared to both PS and NS groups (3.8 and 5.1 vs 3.9 and 5.3 vs 4.0 and 5.4 mm/s, p = 0.03 and p = 0.01, respectively). Moreover, affinity to the beta-2 agonist and levels of exhaled nitric oxide were significantly higher in CS when compared to NS (70 vs 60 mL and 12 vs 10 ppb, p<0.01 and p = 0.03, respectively). A non-significant trend for a higher risk of asthma, atopic eczema and allergic rhinitis was found with more years of swimming practice, particularly in atopic individuals (β = 1.12, 1.40 and 1.31, respectively). After case-case analysis, it was possible to observe that results were not influenced by the inclusion of individuals with asthma. CONCLUSIONS Concluding, swimming pool attendance appears to be associated with autonomic changes and increased baseline airway smooth muscle constriction even in children without asthma.