A cross-sectional study was conducted with a school-based sample at 20 schools selected by systematic random sampling. Participants consisted of children aged 7-8 year old and their parents or primary caregivers. The Wechsler Abbreviated Scale of Intelligence (WASI) was used to evaluate the BIF. The salivary cortisol level was measured by electrochemiluminescence. Children with borderline intellectual functioning (BIF) have an intelligence quotient (IQ) in the range of 71 to 84, where difficulties in academic, social, or vocational are manifested. The child’s intellectual level should be assessed to diagnose BIF, since the can be considered a risk factor for psychiatric morbidity and poor mental health in childhood and adulthood. This limited body of research is particularly impressive, considering that estimates of the prevalence of BIF are about 7.0% of the school-age population.

Previous research has focused mostly on intellectual disability with a known an etiology, such as Down syndrome and children with a more profound intellectual disability, but not on children with a BIF. There are many factors linked to the intellectual disability, with particular emphasis to socioeconomic status (e.g., race/ethnicity, child gender, age, family structure, and economic status). The family socioeconomic status is a complex variable that is composed of the relationship of different factors such as maternal education, caregiver occupation, and family income. In addition, there is evidence supporting the role of childhood stress as a risk factor in the pathway leading to mental disorder, including brain structures, cognition, and expression of symptoms, which can also be an important factor related to impaired learning, worst social interaction ability, and impaired development in children with borderline intellectual disability. The hypothalamic pituitary adrenal (HPA) axis, which has as primary hormonal end product, the hormone cortisol, is a wellknown physiological response system that is activated in acutely stressful situations. Thus, the focus of this study was to examine the prevalence, associated factors and cortisol levels in children with BIF from elementary public schools.Salivary cortisol levels were collected in the morning and measured using the Roche commercial kit according to the manufacturer's instructions (Roche Diagnostics, Mannheim, Germany) using the electrochemiluminescence technique with the COBAS® 6000 analyzer. Salivary cortisol was expressed as ng/mL. Details of these dosages are available elsewhere.In total, 723 children met the inclusion criteria in the study. However, 34 (5.0%) were not located in schools on the assessment days, and 80 (11.0%) did not have the consent of the caregiver. Thus, 609 children were included in the larger study, but 13 caregivers were not located or refused to participate in the study. There was still a loss of 11 cognitive assessments of children who did not complete the assessment. Thus, the sample size of the present study consisted of 585 children and their respective caregivers. The prevalence of BIF was 50.9%.BIF was more prevalent among children with non-white skin color, who had a caregiver with lower education and lower economic classification. In this sense, a meta-analysis study findings that maternal employment was associated with children’s lower cognitive performance, and this result was attenuated by the inclusion of a number of variables that controlled for sample characteristics such as education, income, and race/ethnicity. According to Fryer et al, the differences in children's environments between racial and/or vulnerable groups can explain gaps in intelligence. Also, it has been previously demonstrated that maternal education has positive impacts both on cognitive skills and behavioral problems of children. This is perhaps because the caregiver's education can contribute to the quality of interaction, emotional and verbal involvement, and cognitive stimulation of the child.

Warm Regards,
Alisha
Journal Coordinator
Journal of Translational Neurosciences