Relationship between growth and intelligence quotient in children with Down syndrome

Anna Kłosowska; Agnieszka Kuchta; Agnieszka Ćwiklińska; Kornelia Sałaga-Zaleska; Maciej Jankowski; Przemysław Kłosowski; Arkadiusz Mański; Michał Zwiefka; Paulina Anikiej-Wiczenbach; Jolanta Wierzba

doi:10.21037/tp-21-424

Relationship between growth and intelligence quotient in children with Down syndrome

Transl Pediatr. 2022 Apr;11(4):505-513. doi: 10.21037/tp-21-424.

Affiliations

¹ Department of Pediatrics, Hematology and Oncology, Medical University of Gdańsk, Gdańsk, Poland.
² Department of Clinical Chemistry, Medical University of Gdańsk, Gdańsk, Poland.
³ Department of Endocrinology and Internal Medicine, Medical University of Gdańsk, Gdańsk, Poland.
⁴ Psychological Counselling Centre of Rare Genetic Diseases, University of Gdańsk, Gdańsk, Poland.
⁵ Department of Internal and Pediatric Nursing, Institute of Nursing and Midwifery, Medical University of Gdańsk, Gdańsk, Poland.

Abstract

Background: The relationship between intelligence quotient (IQ) and somatic development, especially growth, has been demonstrated in various groups of children. Down syndrome (DS) is characterized by short stature, overweight, and cognitive impairment. The objective of our work was to assess whether anthropometric measurements [weight, height, body mass index (BMI)] of children with DS correlate with their IQ. The results of the study may be valuable for this population in the light of increasing access to growth hormone therapy (GHT) in various genetic syndromes with short stature. Based on previous studies on children, we hypothesized that a link exists between IQ and somatic development, particularly growth.

Methods: This cross-sectional study included 40 children with DS, who were aged 9-18 years. The studied population was selected from the registry of the Genetic Clinic at the University Clinical Center in Gdańsk (Poland). Anthropometric measurements (weight and height) were taken for all the children, and their BMI was determined using these data. The obtained results were plotted on charts for children with DS. The IQ of the children was assessed using the Stanford Binet Intelligence Scale, Fifth Edition. The correlations between IQ and anthropometric data were analyzed using univariate correlation and multiple regression analyses.

Results: The results showed that full-scale, verbal, and nonverbal IQ correlated with height percentile (P=0.03, P=0.02, and P=0.04, respectively), but not with weight (P=0.26, P=0.19, and P=0.61, respectively) or BMI (P=0.6, P=0.5, and P=0.72, respectively). In multiple linear regression analysis, height percentile remained as an independent determinant of the IQ results after adjusting for birth weight, hypothyroidism with L-thyroxine replacement therapy, and congenital cardiac defect (β=0.48, P=0.018).

Conclusions: The results of our study suggest an association between growth and IQ in children with DS. The presented findings may be valuable for improving access to GHT for populations with genetic syndromes characterized by short stature. However, these should be confirmed by further research with a longitudinal sample of children with DS.

Keywords: Down syndrome (DS); growth; intellectual disability; intelligence quotient (IQ).