The global obesity epidemic has led to a rise in metabolic disturbances such as dyslipidemia, hypertension, and insulin resistance in children and adolescents. The prevalence of metabolic syndrome (MetS) is also increasing in this population. Several lifestyle factors contribute to this increased risk, including unhealthy diets (high consumption of processed foods and low consumption of fruits, vegetables, and wholemeal products), lack of physical activity, high media use and sedentary behaviors, and low well-being due to psychosocial stress. In addition to lifestyle, non-modifiable risk factors such as family history of MetS components, parental education level, maternal BMI, breastfeeding duration, birth weight, and pubertal development play a role. Elevated serum C-reactive protein (CRP), a marker of inflammation, also contributes to the pathogenesis of metabolic disturbances. Metabolic disturbances often persist from childhood into adolescence and adulthood, leading to increased morbidity and cardiovascular risk. This study aimed to build upon previous research using age- and sex-specific cut-offs for MetS components to investigate the effects of lifestyle and non-modifiable factors, including CRP, on metabolic risk statuses during childhood and adolescence in a large, multi-center cohort study.

Existing literature extensively documents the association between lifestyle factors and the development of metabolic disturbances in children and adolescents. Studies have highlighted the negative impact of unhealthy dietary patterns, low physical activity, excessive screen time, and psychosocial stress on weight status and metabolic health. Furthermore, the influence of non-modifiable risk factors, including family history, parental education, maternal BMI, birth weight, and breastfeeding duration, has been established. The role of inflammation, as indicated by elevated CRP, in the development of metabolic disorders is also well-supported. The persistence of metabolic disturbances from childhood into adulthood and their impact on long-term health outcomes have been emphasized in previous research. However, this study provides a unique contribution by integrating multiple lifestyle and non-modifiable risk factors, including CRP, into a comprehensive analysis of the transition from childhood to adolescence, utilizing advanced statistical methods to understand the age-dependent effects of these factors.

This study utilized data from the IDEFICS/I.Family cohort, a multi-center population-based study encompassing children aged 2–9 years at baseline (T0) in eight European countries. The study included 3889 children with data available at baseline and two follow-up examinations (T1 and T3). Metabolic disturbances were assessed based on age- and sex-specific cut-offs for waist circumference, blood pressure, blood glucose, and lipids. Latent transition analysis (LTA) was employed to identify distinct metabolic statuses over time, resulting in five groups: metabolically healthy, abdominal obesity, dyslipidemia, hypertension, and multiple MetS components. Multivariate mixed-effects models were used to analyze the age-dependent associations between lifestyle factors (fruit/vegetable consumption, processed food consumption, sports club membership, media in bedroom, well-being), non-modifiable risk factors (parental education, maternal BMI, family history, birth weight, breastfeeding duration, pubertal status), and CRP (as an age- and sex-specific z-score) and the probabilities of belonging to each metabolic status. The analysis accounted for repeated measurements and missing data using multiple imputation. Odds ratios (ORs) were calculated to represent the associations, with the metabolically healthy group serving as the reference.

The study identified several significant risk factors associated with various metabolic outcomes. Higher maternal BMI was strongly associated with increased risk of abdominal obesity, dyslipidemia, hypertension, and multiple MetS components. Low/medium parental education significantly increased the risk of abdominal obesity and multiple metabolic disturbances. Early puberty was strongly associated with increased risk of abdominal obesity and multiple MetS components. A higher CRP z-score increased the risk of all four metabolic outcomes. Among lifestyle factors, having at least one media device in the bedroom significantly increased the risk of multiple MetS components, with the effect strengthening with age. Not being a member of a sports club increased the risk of dyslipidemia and multiple MetS components. Improved well-being was associated with a reduced risk of abdominal obesity. However, no associations were found between fruit/vegetable consumption, processed food consumption, or breastfeeding duration and any of the metabolic outcomes in the adjusted models.

The findings of this study underscore the importance of both lifestyle and non-modifiable factors in the development of metabolic disturbances during childhood and adolescence. The strong associations observed for maternal BMI, parental education, and early puberty highlight the need for comprehensive preventative strategies addressing these factors. The significant impact of media exposure and lack of sports club membership points towards the effectiveness of interventions aimed at reducing screen time and promoting physical activity. The lack of association between dietary factors and metabolic outcomes in the adjusted models may reflect the complexity of dietary influences or limitations in dietary assessment methods. Further research is needed to investigate the underlying mechanisms linking these factors to metabolic health and to develop effective, targeted interventions. The strong age-dependency observed for media in the bedroom and puberty onset warrants further investigation into how these factors' influence changes over time.

This large-scale study provides compelling evidence for the multifactorial nature of metabolic risk in children and adolescents. Interventions targeting factors such as reducing media exposure in children's bedrooms, promoting sports club membership, and addressing parental education and maternal BMI are promising avenues for prevention. Future research should focus on developing and evaluating comprehensive interventions that address multiple risk factors simultaneously and investigate the long-term effects of early interventions on adult metabolic health. The study’s limitations, such as the reliance on proxy measures for physical activity and screen time, highlight avenues for future refinement.

The study's reliance on proxy measures for physical activity (sports club membership) and sedentary behavior (media in the bedroom) may limit the precision of these associations. The cross-sectional nature of some data (specifically, at baseline) also limits the ability to definitively establish causality. Additionally, the study's focus on European children may limit the generalizability of the findings to other populations with different cultural and socioeconomic contexts. Further research with more objective measures of physical activity and sedentary behavior, longitudinal data collection, and broader geographical representation is warranted.