Effects of 6-Weeks High-Intensity Interval Training in Schoolchildren with Insulin Resistance: Influence of Biological Maturation on Metabolic, Body Composition, Cardiovascular and Performance Non-responses

Abstract

Background: Previous studies have observed significant heterogeneity in the magnitude of change in measures of metabolic response to exercise training. There are a lack of studies examining the prevalence of non-responders (NRs) in children while considering other potential environmental factors involved such as biological maturation.Aim: To compare the effects and prevalence of NRs to improve the insulin resistance level (by HOMA-IR), as well as to other anthropometric, cardiovascular, and performance co-variables, between early (EM) and normal maturation (NM) in insulin-resistance schoolchildren after 6-weeks of HIIT.Methods: Sedentary children (age 11.4 ± 1.7 years) were randomized to either HIIT-EM group (n = 12) or HIIT-NM group (n = 17). Fasting glucose (FGL), fasting insulin (FINS) and homeostasis model assessment of insulin resistant (HOMA-IR) were assessed as the main outcomes, as well as the body composition [body mass, body mass index (BMI), waist circumference (WC), and tricipital (TSF), suprailiac (SSF) and abdominal skinfold (AbdSF)], cardiovascular systolic (SBP) and diastolic blood pressure (DBP), and muscular performance [one-repetition maximum strength leg-extension (1RMLE) and upper row (1RMUR) tests] co-variables were assessed before and after intervention. Responders or NRs to training were defined as a change in the typical error method from baseline to follow-up for the main outcomes and co-variables.Results: There were no significant differences between groups in the prevalence of NRs based on FGL, FINS, and HOMA-IR. There were significant differences in NRs prevalence to decrease co-variables body mass (HIIT-EM 66.6% vs. HIIT-NM 35.2%) and SBP (HIIT-EM 41.6% vs. HIIT-NM 70.5%). A high risk [based on odds ratios (OR)] of NRs cases was detected for FGL, OR = 3.2 (0.2 to 5.6), and HOMA-IR, OR = 3.2 (0.2 to 6.0). Additionally, both HIIT-EM and HIIT-NM groups showed significant decreases (P < 0.05) in TSF, SSF, and AbdSF skinfold, and similar decreases in fasting insulin and HOMA-IR. The HIIT-EM group showed significant decreases in SBP. The HIIT-NM group showed significant increases in 1RMLE and 1RMUR. A large effect size was observed for pre-post changes in TSF in both groups, as well as in SSF in the HIIT-NM group.Conclusion: Although there were no differences in the prevalence of NRs to metabolic variables between groups of insulin resistance schoolchildren of different maturation starting, other NRs differences were found to body mass and systolic BP, suggesting that anthropometric and cardiovascular parameters can be playing a role in the NRs prevalence after HIIT. These results were displayed with several metabolic, body composition, blood pressure, and performance improvements independent of an early/normal maturation or the prevalence of NRs.

Ejercicio físico en pacientes con diabetes e hipertensión: prevalencia de respondedores y no respondedores para mejorar factores de riesgo cardiometabólicos

“…Aunque factores genéticos 13 , y ambientales [14][15][16] han sido escuetamente explorados, aún no se identifican los potenciales factores ambientales que dan cuenta de este fenómeno. Descartando la influencia genética que varía individualmente, no está del todo claro qué parámetros de salud, por ejemplo, composición corporal, presión arterial o marcadores metabólicos como los triglicéridos, presentan mayor o menor prevalencia de sujetos no respondedores en la población adherente a ejercicio.…”

Exercise and glucose control in children with insulin resistance: prevalence of non‐responders

“…After a 6-week exercise training programme in schoolchildren engaging HIT (three sessions/week) Alvarez et al reported a decrease of~22% in both FINS and HOMA-IR in children with IR, and also a prevalence of NRs of~80-90% for decreasing FGL, 30-40% for decreasing FINS and~25-35% for decreasing HOMA-IR in children tested by biological maturation (19). In the present study, it can be seen that individuals who were Rs in one outcome would not necessarily be Rs in another outcome (e.g.…”

“…After the intervention, the delta changes were calculated for each dependent outcome. Consequently, the subjects were categorized as Rs or NRs according to previously described criteria of 2 × TE for the glucose control outcomes (fasting glucose 2 × TE; 3.0 mg/dL, 2 × TE; fasting insulin 2.18 μIU/dL, 2 × TE; HOMA‐IR 0.42) . The odds ratios (ORs) were used to assess the risk for suffering NRs between groups.…”

Interindividual responses to different exercise stimuli among insulin‐resistant women

“…For instance, some individuals show improvements with exercise training (eg, decrease in fasting glucose) and are considered responders , whereas others may not have such a response (eg, no change or even increases in fasting glucose) and are considered non‐responders . Individual variability has been reported mainly regarding fitness‐related variables, and in response to moderate‐intensity endurance (ET), resistance (RT), or high‐intensity interval training (HIT), and also in different age groups such as children, adults, or older populations, The existence of non‐responders for glucose homeostasis‐related variables has been confirmed more recently . In the present study, we confirmed a wide interindividual variability that is independent of the training‐induced changes after HIT, RT, or CT with regard to 20 outcomes and risk parameters, including 9 body composition, 3 cardiovascular, 3 metabolic, and 5 performance parameters.…”

“…3 For instance, some individuals show improvements with exercise training (eg, decrease in fasting glucose) and are considered responders, whereas others may not have such a response (eg, no change or even increases in fasting glucose) and are considered non-responders. 4 The interindividual variability has been reported mainly in the context of fitness-related variables, 5 and in response to moderate-intensity endurance (ET), 3,6 resistance (RT), 7 or high-intensity interval training (HIT), 7 and also in different age groups such as children, 8 adults, 9,10 or older populations. 7,11 The existence of non-responders for glucose homeostasis-related variables has been confirmed more recently.…”