Independent benefits of meeting the 2008 physical activity guidelines to insulin resistance in obese latino children

Adolescent's Health Behaviors and Risk for Insulin Resistance: A Review of the Literature

PURPOSE OF REVIEW

One-third of US adolescents are obese, and related comorbidities exist in this population. Preventing early indicators of these diseases, such as insulin resistance (IR), may impact future morbidity and mortality. Interventions to date have only focused on diet or exercise. Additional targets to prevent disease are needed. This paper reviews the evidence in adolescents examining multiple health behaviors that have been associated with IR.

RECENT FINDINGS

Health behaviors (i.e., diet, activity, sleep) have been individually examined as possible contributors to disease, but an understanding of the complex interplay between these behaviors is lacking. A better understanding of how multiple health behaviors contribute to IR in adolescents is needed. Future studies using both advanced statistical methodology and robust measures of each health behavior may facilitate better understanding of the impact of lifestyle factors on IR and guide intervention strategies to reduce the risk of disease.

Abdominal obesity and low physical activity are associated with insulin resistance in overweight adolescents: a cross-sectional study

BACKGROUND

Previous studies have assessed the metabolic changes and lifestyles associated with overweight adolescents. However, these associations are unclear amongst overweight adolescents who have already developed insulin resistance. This study assessed the associations between insulin resistance and anthropometric, metabolic, inflammatory, food consumption, and physical activity variables amongst overweight adolescents.

METHODS

This cross-sectional study divided adolescents (n = 120) between 10 and 18 years old into 3 groups: an overweight group with insulin resistance (O + IR), an overweight group without insulin resistance (O-IR), and a normal-weight control group (NW). Adolescents were matched across groups based on age, sex, pubertal maturation, and socioeconomic strata. Anthropometric, biochemical, physical activity, and food consumption variables were assessed. Insulin resistance was assessed using homeostatic model assessment (HOMA Calculator Version 2.2.2 from ©Diabetes Trials Unit, University of Oxford), and overweight status was assessed using body mass index according to World Health Organization (2007) references. A chi-square test was used to compare categorical variables. ANOVAs or Kruskal-Wallis tests were used for continuous variables. Multiple linear regression models were used to calculate the probability of the occurrence of insulin resistance based on the independent variables.

RESULTS

The risk of insulin resistance amongst overweight adolescents increases significantly when they reach a waist circumference > p95 (OR = 1.9, CIs = 1.3-2.7, p = 0.013) and watch 3 or more hours/day of television (OR = 1.7, CIs = 0.98-2.8, p = 0.033). Overweight status and insulin resistance were associated with higher levels of inflammation (hsCRP ≥1 mg/L) and cardiovascular risk according to arterial indices. With each cm increase in waist circumference, the HOMA index increased by 0.082; with each metabolic equivalent (MET) unit increase in physical activity, the HOMA index decreased by 0.026.

CONCLUSIONS

Sedentary behaviour and a waist circumference > p90 amongst overweight adolescents were associated with insulin resistance, lipid profile alterations, and higher inflammatory states. A screening that includes body mass index, in waist circumference, and physical activity evaluations of adolescents might enable the early detection of these alterations.