Thyroid status and its association with cognitive functioning in healthy boys at 10 years of age

Abstract

Objective: Thyroid hormones (THs) are crucial for the correct maturation of the CNS and the neurodevelopment of the child. We aimed to investigate the association of TSH and free thyroxine (FT 4 ) levels with cognitive functioning in children from the INMA-Granada cohort studied during their follow-up at the age of 9-11 years. Design: We evaluated 300 children from the original cohort, which comprised 668 eligible mother-son pairs recruited at birth from 2000 to 2002 in Granada (Spain). Methods: FT 4 and TSH concentrations were measured, and cognitive development was assessed using neuropsychological tests (nZ187). Children with chronic disease related to thyroid function and/or cognitive development were excluded. Results: Median TSH and FT 4 levels were 3.1 mIU/ml and 1.2 ng/dl respectively. In multivariable regression analyses adjusted for maternal and child characteristics, children with TSH levels in the top tertile had worse verbal comprehension and immediate and long-term recall. Children with FT 4 levels in the top tertile had better attention and lower impulsivity and were at a lower risk of scoring below the 20th percentile in intelligence quotient (ORZ0.24; 95% CIZ0.08-0.74; PZ0.013) and in abstract reasoning ability (ORZ0.28; 95% CIZ0.09-0.88; PZ0.029). Conclusion: Our findings indicate that circulating THs and TSH may in the top tertile have an impact on cognitive functions; thus, higher TSH slightly but significantly increased the risk of a lower score in certain neuropsychological tests.

The INMA—INfancia y Medio Ambiente—(Environment and Childhood) project: More than 10 years contributing to environmental and neuropsychological research

“…In contrast, high free T4 concentrations were associated with decreased risk of having 1-5 attention deficit symptoms [(OR = 0.25; p < 0.01)] (Alvarez-Pedrerol et al, 2007). Similar results were found in the cohort of Granada with a cross-sectional study, including 300 boys at 10 years of age; children with TSH levels in the higher tertile had worse verbal memory, whereas children with higher free T4 levels had better attention, lower impulsivity and better cognitive scores (Pérez-Lobato et al, 2015b).…”

Neonatal thyroid hormone levels in association with autism spectrum disorder

“…ASD cases did have higher mean neonatal TSH levels than non‐cases in crude comparisons, though differences were quite small. In prior work, higher newborn TSH levels have been associated with lower scores on neuropsychological tests, inattention symptoms, and impairments in general cognitive and executive functioning [Freire et al, ; Pakkila et al, ; Perez‐Lobato et al, ]. We cannot rule out the potential for null findings in our analyses of TSH being masked by high variability of newborn TH levels shortly after birth.…”

Anogenital distance and reproductive outcomes in 9‐ to 11‐year‐old boys: the INMA‐Granada cohort study

“…A random sample of boys in the INMA‐Granada cohort were recontacted and asked to participate in follow‐up visits at the ages of 4–5 years ( N = 220) and 9–11 years ( N = 300). The follow‐up of the children at the age of 9–11 years (during 2010–2012) included interview‐administered questionnaires, physical examination, neuropsychological assessment, and biological sample collection (Pérez‐Lobato et al ., ). A total of 300 boys and their parents from the original cohort (45%) participated in this visit.…”