BACKGROUND:We aimed to explore the differences and relationships in body composition, social function, and comorbidities between children with attention-deficit/hyperactivity disorder (ADHD) and subthreshold ADHD. METHODS:A case-control study was conducted to analyze the differences between children with ADHD and subthreshold ADHD. Logistic regression models were used to analyze the factors influencing social functional impairments and comorbidities. RESULTS:Children with ADHD and subthreshold ADHD had a higher fat mass index than healthy children (p < 0.05). The scores of all six social functional domains were higher in the subthreshold ADHD and ADHD groups than in the control group (p < 0.05). The prevalence of comorbidity was higher in children with subthreshold ADHD and ADHD compared to the control group (p < 0.05). Inattention and comorbid anxiety/depression increased the risk of functional impairments in children with ADHD (full syndrome/subthreshold), whereas a higher fat-free mass index reduced the risk. The severity of hyperactivity was associated with a higher risk of comorbidity in children with ADHD (full syndrome/subthreshold). CONCLUSION:Children with subthreshold ADHD and ADHD had more fat mass and higher rates of social functional impairments and comorbidities than healthy children. There were clinical correlations between body composition, social functional impairments, and comorbidities in ADHD. IMPACT:1. Children with subthreshold ADHD and ADHD had higher fat mass levels than normal children. 2. The social function impairments and comorbidities of children with subthreshold ADHD were similar to those with ADHD. 3. Inattentiveness and anxiety/depression increased the risk of functional impairments in children with ADHD (full syndrome/subthreshold), while a higher fat-free mass index and skeletal muscle-to-body fat ratio reduced the risk.

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in school-age children. Although it has been well documented that children with ADHD are associated with impairment of executive functions including working memory (WM) and inhibitory control, there is not yet a consensus as to the relationship between ADHD and memory-driven attentional capture (i.e., representations in WM bias attention toward the WM-matched distractors). The present study herein examined whether children with ADHD have sufficient cognitive control to modulate memory-driven attentional capture. 73 school-age children (36 with ADHD and 37 matched typically developing (TD) children) were instructed to perform a visual search task while actively maintaining an item in WM. In such a paradigm, the modality and the validity of the memory sample were manipulated. The results showed that under the visual WM encoding condition, no memory-driven attentional capture was observed in TD children, but significant capture was found in children with ADHD. In addition, under the audiovisual WM encoding condition, memory-matched distractors did not capture the attention of both groups. The results indicate a deficit of cognitive control over memory-driven attentional capture in children with ADHD, which can be improved by multisensory WM encoding. These findings enrich the relationship between ADHD and cognitive control and provide new insight into the influence of cross-modal processing on attentional guidance.

Abstract Background We aimed to analyze the characteristics of the body composition of children and adolescents aged 3–17 in Suzhou, China. Methods A cross-sectional study between January 2020 and June 2022 using bioelectrical impedance was conducted to determine the fat mass (FM), fat-free mass (FFM), skeletal muscle mass, and protein and mineral contents of 24,845 children aged 3–17 who attended the Department of Child and Adolescent Healthcare, Children’s Hospital of Soochow University, China. Measurement data was presented in tables as mean ± SD, and groups were compared using the independent samples t-test. Results FM and fat-free mass increased with age in both boys and girls. The fat-free mass of girls aged 14–15 decreased after reaching a peak, and that of boys in the same age group was higher than that of the girls (p < 0.05). There were no significant differences in FM between boys and girls younger than 9- and 10-years old. The percentage body fat (PBF) and FM index of girls increased rapidly between 11 and 15 years of age (p < 0.05), and those of boys aged 11–14 were significantly lower (p < 0.05), suggesting that the increase in body mass index (BMI) was mainly contributed by muscle mass (MM) in boys. Conclusions The body composition of children and adolescents varies according to their age and sex. A misdiagnosis of obesity made on the basis of BMI alone can be avoided if BMI is used in combination with FM index, percentage body fat, and other indexes.

Abstract Background We aimed to analyze the characteristics of the body composition of children and adolescents aged 3–17 in Suzhou, China. Methods A cross-sectional study between January 2020 and June 2022 using bioelectrical impedance was conducted to determine the fat mass (FM), fat-free mass (FFM), skeletal muscle mass, and protein and mineral contents of 24,845 children aged 3–17 who attended the Department of Child and Adolescent Healthcare, Children’s Hospital of Soochow University, China. Normally distributed data were expressed as mean ± SD, and groups were compared using the independent samples t-test. Results FM and fat-free mass increased with age in both boys and girls. The fat-free mass of girls aged 14–15 decreased after reaching a peak, and that of boys in the same age group was higher than that of the girls (p < 0.05). There were no significant differences in FM between boys and girls younger than 9 years old. The percentage body fat (PBF) and FM index of girls increased rapidly between 11 and 15 years of age (p < 0.05), and those of boys aged 11–14 were significantly lower (p < 0.05), suggesting that the increase in body mass index (BMI) was mainly contributed by muscle mass (MS) in boys. Conclusions The body composition of children and adolescents varies according to their age and sex. A misdiagnosis of obesity made on the basis of BMI alone can be avoided if BMI is used in combination with FM index, percentage of body fat, and other indexes.