A pathophysiologic approach to growth problems in children with attention-deficit/hyperactivity disorder

Effect of methylphenidate on height in pediatric attention-deficit hyperactivity disorder patients: a systematic review and meta-analysis

Methylphenidate (MPH), a first-line treatment for attention-deficit hyperactivity disorder (ADHD) management, has been the focus of debate for decades regarding its effect on growth. The aim of this PRISMA meta-analysis was to determine the effect of MPH on height in children/adolescents with ADHD and its predictive factors based on literature reports. Available full-text articles were systematically reviewed to identify clinical studies of pediatric ADHD patients with height Z-score (HZS) data for monotherapy MPH-treated and non-treated groups. We estimated standardized mean differences (SMDs) of HZS or its changes from baseline (ΔHZS) between groups, then identified associated factors through subgroup analyses and meta-regression. For before-after treatment studies, the paired standard errors of ΔHZS were re-estimated to demonstrate in the forest plot. Risk of bias was analyzed using the Newcastle-Ottawa Scale. Among the 29 eligible studies, 26 reported ΔHZS with self-control groups, and ΔHZS or absolute HZS were compared to other external controls in 11 studies. A significant reduction was observed between post-MHP and pre-MPH use, with high heterogeneity (SMD =  - 0.40; 95% confidence interval = [ - 0.54,  - 0.27]; I2 = 91%). The study region, ADHD subtype, and stimulant-naïve status of patients at baseline may modify the effect on HZS. Because of the high clinical heterogeneity in observational studies, clinicians should consider the negative effect of MPH on height in ADHD patients by determining whether patients fulfill appropriate high-risk criteria. Further well-designed longitudinal studies are required to better quantify this effect, especially with prolonged treatment.

Interrelationships among growth hormone, thyroid function, and endocrine-disrupting chemicals on the susceptibility to attention-deficit/hyperactivity disorder

Abnormal growth hormones and thyroid function may be linked to pathophysiology of attention-deficit/hyperactivity disorder (ADHD). Phthalates and bisphenol-A (BPA), two endocrine-disrupting chemicals (EDCs), may affect the human endocrine system. In this study, we aimed to perform a comprehensive investigation of whether growth hormone, thyroid function, and EDCs exhibited differential levels between ADHD patients and healthy controls. In total, 144 children with ADHD and 70 healthy control subjects were enrolled. Their endocrine systems were evaluated using the serum levels of insulin-like growth factor-1 (IGF-1), IGF-binding protein-3 (IGFBP-3), thyroid-stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), and Free T4. The urinary levels of EDCs, including monoethyl phthalate (MEP), mono-methyl phthalate (MMP), monoethylhexyl phthalate (MEHP), mono-n-butyl phthalate (MnBP), monobenzyl phthalate (MBzP), and BPA, were also examined. Patients with ADHD had lower IGF-1 levels than healthy controls (p = 0.003), but we observed no significant difference in IGFBP-3, TSH, T3, T4, or Free T4. Compared to the control group, patients with ADHD demonstrated higher MEHP levels (p = 0.043), MnBP (p = 0.033), and MBzP (p = 0.040). Furthermore, MEHP levels (p < 0.001) and BPA levels (p = 0.041) were negatively correlated with IGF-1 levels, while IGF-1 levels were negatively correlated with principal components consisting of ADHD clinical symptoms and neuropsychological performance variables. We suggest that MEHP exposure may be associated with decreased serum levels of IGF-1 and increased risk of ADHD. The mechanism underlying this association may be important for protecting children from environmental chemicals that adversely affect neurodevelopment.

Impact of CNS Stimulants for Attention-Deficit/Hyperactivity Disorder on Growth: Epidemiology and Approaches to Management in Children and Adolescents

Central nervous system stimulants are established treatments for pediatric attention-deficit/hyperactivity disorder with robust efficacy data. Reductions in appetite, weight, and growth velocity are some of the most common concerns regarding the long-term use of central nervous system stimulants in developing children. They are associated with suppression of weight and body mass index in childhood. However, both weight and body mass index often progressively increase over adolescence at rates faster than those seen in non-attention-deficit/hyperactivity disorder youth to the degree that attention-deficit/hyperactivity disorder is associated with elevated body mass index by the end of adolescence regardless of medication use. The capacity of central nervous system stimulants to slow growth was identified 50 years ago. Recent work has established that the growth deficits accumulate during the first 2 years of use and may persist provided medication is used. Early initiation coupled with persistent use through adolescence is most likely to be associated with clinical impactful growth suppression. There has been limited formal investigation of treatments for stimulant-associated reductions in weight and height. The most robust evidence exists for drug holidays improving weight gain. Observational studies suggest that limiting lifetime exposure or discontinuing medication is associated with greater adult height. Additional research is needed to identify the causal mechanisms driving the observed slowing in growth as well as the identification of predictors of clinically impactful growth suppression.

The Association Between Metabolic Syndrome, Obesity-Related Outcomes, and ADHD in Adults With Comorbid Affective Disorders

OBJECTIVE

ADHD may predispose to obesity, a metabolic syndrome component. Affective disorders are also associated with MetSyn and ADHD. This study examined whether ADHD confers any added risk of MetSyn and obesity-related associations in a large sample with varying stages of affective disorders.

METHOD

Participants included 2,303 adults from the Netherlands Study of Depression and Anxiety. Three groups were compared (controls, those with depressive/anxiety disorders without ADHD; and those with depressive/anxiety disorders and ADHD) for presence of MetSyn risk factors, body mass index, and waist-hip ratio. ADHD symptoms were identified by using a T-score > 65 (Conners Adult ADHD Rating Scale).

RESULTS

Multivariable analyses were additionally adjusted for sociodemographic, lifestyle, health factors, and affective disorders. Analyses showed no significant association between MetSyn, obesity-related variables, and comorbid ADHD. High Inattention and Hyperactivity/Impulsivity symptoms were not associated with MetSyn.

CONCLUSION

This study did not confirm that MetSyn and obesity-related parameters are increased in comorbid ADHD.