Fasting insulin resistance affects the prevalence of metabolically healthy obesity in Brazilian adolescents.

AIM: We aimed to assess the influence of fasting insulin resistance on metabolically healthy obesity (MHO) prevalence in adolescents and to identify associated factors.
METHODS: This retrospective, registry-based, cross-sectional study included 418 (51.9% girls) 10- to 18-year-old adolescents with obesity from a tertiary outpatient clinic in Sao Paulo, Brazil, between 2009 and 2013. The prevalence of MHO was estimated according to two definitions: (i) no cardiometabolic risk factors (CMRF) by the International Diabetes Federation parameters and (ii) no CMRF and homeostatic model assessment for insulin resistance <3.16. Adjusted prevalence ratios and 95% confidence intervals (CI) evaluated the association of gender, age, pubertal stages, skin colour and degree of obesity with MHO.
RESULTS: Metabolically healthy obesity prevalence was lower in definition II than definition I (12.7%; 95% CI 9.1-16.3% versus 43.1%; 95% CI 38.0-48.2%, respectively). Adjusted results showed negative association between severe obesity and MHO by both definitions (p ≤ 0.01). Male and later pubertal stages were also less likely to have MHO, but neither remained significant in definition II.
CONCLUSION: Metabolically healthy obesity prevalence decreased when insulin resistance was part of the definition. Detecting pre-clinical insulin resistance may improve the management of treatment-seeking adolescents, especially when they present no CMRF. ©2018 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.