No abstract

The purpose of this study was to identify the relevance of a set of risk factors for insulin resistance in adolescents from Europe and to consider their possible gender-specific associations. The Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) was conducted in 1053 European adolescents (mean age, 14.9 years) in a school setting in 9 countries. Three anthropometric markers of body fat and a dietary index were calculated. Total energy intake was estimated from a questionnaire. C-reactive protein, leptin, and vitamin D were assessed, and physical activity, cardiorespiratory fitness, and muscular strength were measured. Center, socioeconomic status, pubertal status, and season were used as potential confounders. The main outcome was the homeostasis model assessment used as a marker of insulin resistance. Correlations, analyses of covariance, and logistic regression models were used. In males, leptin was the only risk factor for insulin resistance after adjusting for confounders including markers of body fat (odds ratios (ORs) from 1.49 to 1.60). In females, leptin, vitamin D, and fitness were the remaining independent risk factors for insulin resistance after adjustments (OR 2.11; 95% confidential interval (CI) 1.29-3.45; OR 0.50, 95% CI 0.31-0.80; and OR 0.54, 95% CI 0.33-0.87, respectively). Our observations suggest a gender dimorphism in the identification of risk factors for high insulin resistance. Preventive strategies should focus on improving modifiable factors such as cardiorespiratory fitness and on ensuring vitamin D sufficiency. Randomized controlled trials focusing on these strategies are necessary to test their efficacy.

Emerging data indicate that higher levels of insulin resistance (IR) are common among children and adolescents and are related to cardiometabolic risk; therefore, IR requires consideration early in life. In addition, there is a lack of conclusive evidence regarding the role of dietary nutrients on IR. The Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) was conducted in European adolescents aged 12·5 -17·5 years. A total of 637 participants with valid homeostasis model assessment (HOMA) index data and who completed at least a 2 d 24 h dietary recall were included in the study (60 % of the total HELENA-CSS sample). There were two dietary indices calculated, with the only difference between them being the inclusion or not of physical activity (PA). Markers of IR such as HOMA and the quantitative insulin sensitivity check index (QUICKI) were calculated. Pubertal status, BMI and cardiorespiratory fitness (CRF) were measured as potential confounders. The dietary index including PA was inversely associated with HOMA and directly with the QUICKI in females, but not in males, after adjusting for pubertal status, centre, BMI and CRF. In conclusion, the present study indicates that considering PA as part of the dietary index is of relevance as the resulted index is inversely related to IR independently of potential confounders including CRF. Overall, these findings suggest that intervention studies aimed at preventing IR in young people should focus on increasing the quality of the diet and also on including an optimal PA level in healthy adolescents.

Palabras clave:Resistencia a la insulina. Adolescente. Grasa corporal. Obesidad. ResumenAntecedentes: los diferentes componentes corporales pueden contribuir al desarrollo de resistencia a la insulina y diabetes mellitus de tipo 2. El objetivo del presente estudio fue examinar la asociación entre la masa grasa y la masa libre de grasa con marcadores de resistencia a la insulina, valorando de forma independiente cada uno de ellos y aportando información específi ca por sexo, en una amplia cohorte de adolescentes europeos. Métodos: se realizó un estudio transversal en el ámbito escolar en 925 (430 varones) adolescentes (14,9 ± 1,2 años). Se midieron peso, talla, pliegues cutáneos e impedancia bioeléctrica. Se calcularon índices de masa grasa y libre de grasa y se calculó el índice HOMA. Se realizaron análisis de regresión múltiple ajustándolos según varios factores de confusión, incluyendo la masa libre de grasa y masa grasa cuando fue posible. Resultados: los índices de masa grasa se asociaron positivamente con HOMA (todos p < 0,01) después de ajustarlos según todos los factores de confusión, incluidos los marcadores de masa libre de grasa, en ambos sexos. Los índices de masa libre de grasa se asociaron con HOMA, tanto en hombres como en mujeres, después de ajustar por país, estadio puberal, nivel socio-económico y capacidad cardiorrespiratoria, pero las asociaciones desaparecieron al incluir marcadores de masa grasa en el modelo de ajuste. Conclusión: índices de masa grasa obtenidos según diferentes métodos se asocian con la resistencia a la insulina, independientemente de varios factores de confusión, incluyendo los índices de masa libre de grasa. Además, la cantidad de masa grasa infl uye en la relación de la masa libre de grasa con resistencia a la insulina en adolescentes europeos. Los estudios futuros deberían centrarse no solo en el papel de la masa grasa, sino también en el de otros componentes corporales como la masa libre de grasa, ya que su papel podría variar dependiendo del nivel y distribución de masa grasa. AbstractBackground: The different body components may contribute to the development of insulin resistance and type 2 diabetes mellitus. The aim of the present study was to examine the association of fat mass and fat free mass indices with markers of insulin resistance, independently of each other and giving, at the same time, gender-specifi c information in a wide cohort of European adolescents. Methods: A cross-sectional study in a school setting was conducted in 925 (430 males) adolescents (14.9 ± 1.2 years). Weight, height, anthropometric, bioimpedance and blood parameters were measured. Indices for fat mass and fat free mass, and homeostatic model assessment (HOMA) were calculated. Multiple regression analyses were performed adjusting for several confounders including fat free mass and fat mass when possible. Results: Indices of fat mass were positively associated with HOMA (all p < 0.01) after adjusting for all the confounders including fat free mass indices, in both sexes. Fat free mass in...