Healthy Chilean Adolescents with HOMA-IR ≥ 2.6 Have Increased Cardiometabolic Risk: Association with Genetic, Biological, and Environmental Factors

Neck circumference as a predictor of metabolic syndrome, insulin resistance and low-grade systemic inflammation in children: the ACFIES study

Background

The current study aims to evaluate the association between neck circumference (NC) and several cardio-metabolic risk factors, to compare it with well-established anthropometric indices, and to determine the cut-off point value of NC for predicting children at increased risk of metabolic syndrome, insulin resistance and low-grade systemic inflammation.

Methods

A total of 669 school children, aged 8–14, were recruited. Demographic, clinical, anthropometric and biochemical data from all patients were collected. Correlations between cardio-metabolic risk factors and NC and other anthropometric variables were evaluated using the Spearman’s correlation coefficient. Multiple linear regression analysis was applied to further examine these associations. We then determined by receiver operating characteristic (ROC) analyses the optimal cut-off for NC for identifying children with elevated cardio-metabolic risk.

Results

NC was positively associated with fasting plasma glucose and triglycerides (p = 0.001 for all), and systolic and diastolic blood pressure, C-reactive protein, insulin and HOMA-IR (p < 0.001 for all), and negatively with HDL-C (p = 0.001). Whereas, other anthropometric indices were associated with fewer risk factors.

Conclusions

NC could be used as clinically relevant and easy to implement indicator of cardio-metabolic risk in children.

[Identification of cutoff points for Homeostatic Model Assessment for Insulin Resistance index in adolescents: systematic review]

OBJECTIVE

To identify cutoff points of the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index established for adolescents and discuss their applicability for the diagnosis of insulin resistance in Brazilian adolescents.

DATA SOURCE

A systematic review was performed in the PubMed, Lilacs and SciELO databases, using the following descriptors: "Adolescents", "insulin resistance" and "ROC curve". Original articles carried out with adolescents published between 2005 and 2015 in Portuguese, English or Spanish languages, which included the statistical analysis using ROC curve to determine the index cutoff (HOMA-IR) were included.

DATA SYNTHESIS

A total of 184 articles were identified and after the study phases were applied, seven articles were selected for the review. All selected studies established their cutoffs using a ROC curve, with the lowest observed cutoff of 1.65 for girls and 1.95 for boys and the highest of 3.82 for girls and 5.22 for boys. Of the studies analyzed, one proposed external validity, recommending the use of the HOMA-IR cutoff >2.5 for both genders.

CONCLUSIONS

The HOMA-IR index constitutes a reliable method for the detection of insulin resistance in adolescents, as long as it uses cutoffs that are more adequate for the reality of the study population, allowing early diagnosis of insulin resistance and enabling multidisciplinary interventions aiming at health promotion of this population.

High cardiometabolic risk in healthy Chilean adolescents: associations with anthropometric, biological and lifestyle factors

OBJECTIVE

To analyse the prevalence of cardiovascular risk factors in healthy adolescents of low to middle socio-economic status and to study the influence of anthropometric, biological and lifestyle factors on the risk of metabolic syndrome (MetS).

DESIGN

Cross-sectional study. BMI, waist circumference, blood pressure, fat and lean mass (by dual-energy X-ray absorptiometry), TAG, HDL-cholesterol, glucose, insulin, homeostatic model assessment-insulin resistance index (HOMA-IR), food intake and physical activity were measured. Cardiovascular risk factors were defined using the International Diabetes Federation criteria and insulin resistance using HOMA-IR ≥2.6. Bivariate and multivariate regressions examined the associations between MetS and anthropometric, biological and lifestyle factors.

SETTING

Observational cohort study including Chilean adolescents, who were part of a follow-up study beginning in infancy.

SUBJECTS

Adolescents aged 16-17 years (n 667).

RESULTS

In the sample, 16.2% had obesity and 9.5% had MetS. Low HDL-cholesterol (69.9%), abdominal obesity (33.3%) and fasting hyperglycaemia (8.7%) were the most prevalent cardiovascular risk factors. In males, obesity (OR=3.7; 95% CI 1.2, 10.8), insulin resistance (OR=3.0; 95% CI 1.1, 8.2), physical inactivity (OR=2.9; 95% CI 1.1, 7.7) and sarcopenia (OR=21.2; 95% CI 4.2, 107.5) significantly increased the risk of MetS. In females, insulin resistance (OR=4.9; 95% CI 1.9, 12.6) and sarcopenia (OR=3.6; 95% CI 1.1, 11.9) were significantly associated with MetS.

CONCLUSIONS

High prevalences of obesity, abdominal obesity, dyslipidaemia, fasting hyperglycaemia and MetS were found in healthy adolescents. In both sexes, sarcopenia and insulin resistance were important risk factors of MetS. Promotion of active lifestyles at the school level and regulation of the sale of energy-dense foods are needed.