Low cardiorespiratory fitness and obesity for ADHD in childhood and adolescence: A 6‐year cohort study

Abstract

Attention‐deficit/hyperactivity disorder (ADHD) is a prevalent disorder in childhood and identifying risk factors associated with developing ADHD during childhood and adolescence is relevant from a clinical and epidemiological point of view. This work examines (a) whether overweight/obesity and low cardiorespiratory fitness (CRF) are associated with increased ADHD symptoms in childhood (cross‐sectional analysis), and (b) whether overweight/obesity and low CRF levels during childhood predict increased ADHD symptoms in adolescence (longitudinal analysis). Data were examined from a longitudinal study of Estonian inhabitants who took part in the European Youth Heart Study (EYHS) in 1998 and 1999 (baseline age 9 years), who were re‐evaluated 6 years later as part of the longitudinal Estonian Children Personality Behaviour and Health Study (ECPBHS). CRF was determined via an incremental maximal cycle‐ergometer test, overweight/obesity was based on body mass index (BMI), and the 7‐point af Klinteberg Hyperactivity Scale was used to assess ADHD symptoms at both time points. In the cross‐sectional analysis, children with overweight/obesity were at greater risk of ADHD symptoms compared to underweight/normal weight children, as were those unfit compared to fit children (OR = 1.92 and 95%CI = 1.02‐3.55, and OR = 1.84 and 95%CI = 1.13‐2.98, respectively). The cross‐sectional association between BMI and ADHD symptoms was mediated by CRF (z = 2.116, 42.9%; P = .034). The longitudinal analysis showed being unfit in childhood was associated with a greater risk of increased ADHD symptoms 6 years later in adolescence (OR = 2.26 and 95%CI = 1.14‐4.47), even after adjusting for baseline ADHD symptoms and BMI. Our result suggests that being unfit is an additional risk factor for increased ADHD symptoms during childhood and adolescence. The association between BMI and ADHD symptoms was mediated by CRF in the cross‐sectional analysis, and no association was seen between overweight/obesity and increased ADHD symptoms.

Motor Functional Characteristics in Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorders: A Systematic Review

“…We did not include these deficits as specific characteristics of ADHD/ASDs. Indeed, previous studies that assessed and examined activities of daily living reported that people with ADHD/ASDs had significantly lower levels of physical activity and motor functioning than TDs, 81–85 which is further supported by the findings of the current systematic review. Only part of the study by de Moraes et al 76 showed better results by people with ASDs than TDs.…”

The Efficacy of Physical Activity for Children with Attention Deficit Hyperactivity Disorder: A Meta-Analysis of Randomized Controlled Trials

“…Acute physical activity might have immediate benefits on ADHD symptoms such as the induction of exercise-related changes in brain activity ( Neudecker et al, 2015 ) and the fascilitation of attention ( Chang et al, 2012 ) or self-esteem ( Dale et al, 2019 ). Accumulating these acute effects, regular exercise might lead to long-lasting improvements in ADHD symptoms through (psycho-) physiological or psychosocial adaptations such as increased fitness, executive functioning ( Muntaner-Mas et al, 2021 ; Rivera-Brown & Frontera, 2012 ; Scudder et al, 2014 ), better peer relationships or social skills ( Balish et al, 2014 ; Lee et al, 2014 ; Storebø et al, 2019 ). While the effects of acute and regular exercise are both important in the treatment of ADHD patients, they are difficult to combine in meta-analytic approaches.…”

Association of Impulsivity With Food, Nutrients, and Fitness in a Longitudinal Birth Cohort Study

“…As mentioned above, several studies in children have been dedicated to studying impulsivity indirectly via its inclusion in the definition of ADHD. Besides the studies mentioned in the introduction, a previous study of the ECPBHS participants indicated that being unfit in childhood (at age 9) increases the likelihood of exhibiting ADHD symptoms 6 years later in adolescence, adjusted for baseline ADHD symptoms and BMI ( Muntaner-Mas et al, 2021 ). Nevertheless, dedicated studies, especially on the non-clinical adult samples, remain scarce.…”

“…We expected that such associations would not be strong, but possible, as certain types of eating disorders and food choices have been previously associated with impulsivity. In particular, based on previous research, we expected that high maladaptive impulsivity would be associated with increased BMI and reduced cardiorespiratory fitness because the latter was predictive of symptoms of attention-deficit hyperactivity disorder at a young age in this sample ( Muntaner-Mas et al, 2021 ). A primary role of many vitamins and metal ions is to serve as cofactors in neurotransmitter synthesis or ion channel gating, respectively, with implications particularly to both fast inhibitory and excitatory neurotransmission.…”