Determinants of High Fasting Insulin and Insulin Resistance Among Overweight/Obese Adolescents.

Jerri Chiu Yun Ling,Mohd Nahar Azmi Mohamed,Muhammad Yazid Jalaludin,Nur Lisa Zaharan,Zahurin Mohamed,Sanjay Rampal

doi:10.1038/srep36270

Abstract

Hyperinsulinaemia is the earliest subclinical metabolic abnormality, which precedes insulin resistance in obese children. An investigation was conducted on the potential predictors of fasting insulin and insulin resistance among overweight/obese adolescents in a developing Asian country. A total of 173 overweight/obese (BMI > 85th percentile) multi-ethnic Malaysian adolescents aged 13 were recruited from 23 randomly selected schools in this cross-sectional study. Waist circumference (WC), body fat percentage (BF%), physical fitness score (PFS), fasting glucose and fasting insulin were measured. Insulin resistance was calculated using homeostasis model assessment of insulin resistance (HOMA-IR). Adjusted stepwise multiple regression analysis was performed to predict fasting insulin and HOMA-IR. Covariates included pubertal stage, socioeconomic status, nutritional and physical activity scores. One-third of our adolescents were insulin resistant, with girls having significantly higher fasting insulin and HOMA-IR than boys. Gender, pubertal stage, BMI, WC and BF% had significant, positive moderate correlations with fasting insulin and HOMA-IR while PFS was inversely correlated (p < 0.05). Fasting insulin was primarily predicted by gender-girls (Beta = 0.305, p < 0.0001), higher BMI (Beta = −0.254, p = 0.02) and greater WC (Beta = 0.242, p = 0.03). This study demonstrated that gender, BMI and WC are simple predictors of fasting insulin and insulin resistance in overweight/obese adolescents.

Highlights

Similar to other countries worldwide, Malaysia, a multi-ethnic country in Southeast Asia is experiencing an increase in childhood obesity
The use of readily available measuring tools to assess overweight and obese Malaysian adolescents en masse had demonstrated that selected indices of adiposity (BMI, Waist circumference (WC), waist to height ratio (WHtR) and BF%) as well as gender and pubertal stage had significant positive correlations with fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR)
A fitted model consisting of gender, body mass index (BMI) and WC from stepwise multiple regression analysis explained more than a quarter of the variance of fasting insulin and HOMA-IR

Summary

Introduction

Similar to other countries worldwide, Malaysia, a multi-ethnic country in Southeast Asia is experiencing an increase in childhood obesity. Dual-energy x-ray absorptiometry and maximal oxygen uptake are used as laboratory gold standard tests to quantify adiposity and cardiovascular fitness respectively[11,12]. These gold standard tests are expensive, time-consuming and clinically impractical for mass population surveillance, in public health care and school settings. The aim of this study was to identify the predictors of high fasting insulin and insulin resistance (as measured by HOMA-IR) among overweight and obese Malaysian adolescents, by employing three clinically accessible instruments, namely a WC measuring tape, BIA, and the Modified Harvard Step Test (MHST)[22,23,24] for mass population testing. This study aimed to examine the relationship between fasting insulin and HOMA-IR with selected cardiovascular risk factors, namely blood pressure (BP) and lipid profiles among the adolescents

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Conclusion