[Association between serum zinc level and hypercholesterolemia and insulin resistance in Brazilian children]

Obesogenic environment around schools is associated with atherogenic risk in Brazilian children

INTRODUCTION

Cardiometabolic risk factors often emerge in childhood, increasing the risk of cardiovascular diseases in adulthood. The school environments represent an important active space in a child's routine and may influence their health status.

METHODS

In this cross-sectional study, we aimed to evaluate the clustering of cardiometabolic risk factors and its association with the obesogenic and leptogenic environment around schools. A total of 378 children (181 boys; 197 girls) aged 8 and 9 years, enrolled in all urban schools of Viçosa, Minas Gerais, Brazil, were evaluated. Concentrations of high-density lipoprotein-cholesterol (HDL-c) and triglycerides (TG), and the insulin resistance (HOMA-IR), waist circumference (WC), and mean arterial pressure (MAP) were measured. The neighborhood income, walkability index, predominantly ultra-processed food stores, public spaces for leisure and/or physical activities, traffic accidents, crime and green spaces densities were assessed in 400 road network buffers around schools. To test association of the obesogenic and leptogenic environment around schools with cardiometabolic risk clustering, binary logistic regression models were performed with generalized estimating equations.

RESULTS

"Obesogenic school environments" had greater densities of ultra-processed food stores, crime and traffic accidents, and higher walkability. The "↓ Atherogenic risk" cluster consisted of higher HDL-c values. There was an inverse association between the obesogenic environment around schools and a child's "↓ atherogenic risk" clustering (OR = 0.63; p < 0.001).

CONCLUSION

We concluded that public policies aimed at modifying the environment around schools, by providing healthier food options and safe conditions for active mobility, are essential to prevent child's atherogenic risk.

[Zinc and its relation to insulin resistance in children]

Zinc is an essential trace element involved in catalytic, structural, and regulatory functions, participating also in the metabolism of nutrients. Its role in insulin resistance appears to be of great importance, as it is involved in oxidative stress, the endocrine regulation of insulin, and the regulation of glucose uptake. For this reason, both intake and serum levels of zinc are inversely related to insulin resistance. Currently, zinc intake in children is low, and zinc deficiency exists in a significant proportion. Zinc can be found in meat, fish, eggs, and dairy products. Although it certainly is present in foods of plant origin, their high phytate contents generally reduce its bioavailability. For this reason, it is important to monitor intake throughout childhood, and to consider supplementation in children with insulin resistance or obesity.

Neck circumference cutoff points to identify excess android fat

OBJECTIVE

To evaluate the ability of neck circumference to identify excess android fat and to propose cutoff points for Brazilian children.

METHOD

This was a cross-sectional study with 376 children aged 8 and 9 years enrolled in public and private schools in the urban area of the municipality of Viçosa, Minas Gerais. A semi-structured questionnaire containing sociodemographic and lifestyle information was applied. The following were collected: neck circumference, weight, and height for the calculation of body mass index. The percentage of fat in the android region was determined by dual energy X-ray absorptiometry. Linear regression analysis was used to evaluate the association between neck circumference and android fat, adopting a significance level of 5%. Receiver operating characteristic curves were used to evaluate the capacity of neck circumference to determine the excess android fat, as well as to estimate the cutoff points of neck circumference according to gender.

RESULTS

Multiple linear regression showed an association between neck circumference and android fat (β: 2.94, 95% CI: 2.41, 3.47). Neck circumference was able to identify excess android fat in girls (AUC: 0.909, 95% CI: 0.999, 0.945) and boys (AUC: 0.938, 95% CI: 0.892, 0.968). The proposed cutoff points showed satisfactory sensitivity, specificity, and predictive values.

CONCLUSIONS

Neck circumference is capable of identifying excess android fat in children and can be used in clinical practice and in population studies to determine central adiposity. The proposed cutoff points were satisfactory, but should be validated for other populations.