Prospective control abilities during visuo-manual tracking in children with 22q11.2 Deletion syndrome compared to age- and IQ-matched controls

To examine whether children with a 22q11.2 Deletion syndrome (22q11.2DS) are able to use prospective control, 21 children with 22q11.2DS (mean age = 9.6 ± 1.9; mean FSIQ = 73.05 ± 10.2) and 21 control children (mean age = 9.6 ± 1.9; mean FSIQ = 73.38 ± 12.0) were asked to perform a visuo-manual tracking task in which they had to track a cursor rhythmically between 2 target zones. Children with 22q11.2DS performed worse than the age- and IQ-matched controls (higher absolute time and distance errors) suggesting that the 22q11.2DS group experiences an additional (syndrome specific) processing deficit that cannot be attributed to their lower intellectual abilities. The 22q11.2DS group neither the control group improved their tracking performance throughout five identical full feedback conditions of the tracking task possibly due to a slow visuo-motor adaptation process, a short span of attention and cognitive flexibility impairments. The results showed that both the 22q11.2DS group and the controls had difficulties anticipating the movement of the target (prospective control) and thus are assumed to rely more on feedback instead of on an internal representation of the movement.     

Evidence of gray matter reduction and dysfunction in chromosome 22q11.2 deletion syndrome

Chromosome 22q11.2 deletion syndrome (22q11DS) is associated with cognitive deficits and morphometric brain abnormalities in childhood and a markedly elevated risk of schizophrenia in adolescence/early adulthood. Determining the relationship between neurocognition and neuroimaging findings would yield crucial information about childhood neurodevelopment and provide a basis for the study of the trajectory that occurs on the pathway to psychosis. We compared morphometric brain findings between non-psychotic children with 22q11DS (n = 22) and healthy controls (n = 16), and examined the association between neurocognitive functioning and morphometric brain findings. Volumetric regional gray matter differences between the 22q11DS and control subjects were measured, and correlations of the regional gray matter volumes and neurocognition were performed. Children with 22q11DS demonstrated reductions in gray matter in several brain regions, chiefly the frontal cortices, the cingulate gyrus and the cerebellum. The volumetric reductions in these salient areas were associated with poor performance in sustained attention, executive function and verbal memory; however, the relation of brain volume with cognitive performance did not differ between the patient and control groups. Thus, children with 22q11DS demonstrate gray matter reductions in multiple brain regions that are thought to be relevant to schizophrenia. The correlation of these volumetric reductions with poor neurocognition indicates that these brain regions may mediate higher neurocognitive functions implicated in schizophrenia.     

Differences in counter-movement jump between boys with and without intellectual disability

The purpose of this study was to describe the performance and biomechanical parameters of the counter-movement jump for young people with ID, in comparison with age matched individuals without ID. Volunteers with ID (n = 13; age = 15.3 ± 1.6 years; Wisk III intelligence quotient 55.6 ± 11.2) and without ID (n = 13; age = 15.4 ± 1.2 years) performed maximal counter-movement jumps, while knee kinematics, vertical ground reaction forces and electromyographic activity of the vastus lateralis and biceps femoris were captured. Individuals without ID jumped higher than their counterparts with ID and had lower take-off velocity, lower knee joint power and stiffness, lower knee joint extension angle and angular velocity, longer braking and propulsion phase, lower agonist and higher antagonist EMG activity. These results give an insight on possible causes for the performance deficit in CMJ in persons with ID and give the potential for such individuals to improve their ability to jump higher and more efficiently.     

Association of IL-12p70 and IL-6:IL-10 ratio with autism-related behaviors in 22q11.2 deletion syndrome: A preliminary report

22q11.2 deletion syndrome (22q11DS) is a genetic disorder that conveys a significant risk for the development of social behavior disorders, including autism and schizophrenia. Also known as DiGeorge syndrome, 22q11DS is the second most common genetic disorder and is characterized by an elevated risk for immune dysfunction, up to 77% of individuals have an identifiable immune deficiency. We hypothesize that this immune dysfunction could contribute to the elevated risk of impaired social behavior seen in 22q11DS. The current study begins to elucidate these immune deficits and link them with the behavioral alterations associated with the disorder. Serum concentrations of a series of cytokines were examined, using a multiplex immunoassay, in sixteen individuals with 22q11DS and screened for autism-related behavior using the Autism Diagnostic Interview-Revised (ADI-R). This preliminary study examined correlations between specific immune proteins and each of the ADI-R algorithm scores (social, communication, and repetitive behavior). The inflammatory cytokine IL-1β, as well as the ratio between the inflammatory cytokine IL-6 and the anti-inflammatory cytokine IL-10, were correlated with social scores (r = 0.851, p = 0.004; r = 0.580, p = 0.018). In addition, the inflammatory cytokines interferon gamma and IL-12p70 were correlated with repetitive behaviors (r = 0.795, p = 0.033; r = 0.774, p = 0.002). Interestingly, IL-12 has been reported to be increased in autistic children. These data show a positive association between severity of autism-related behaviors and level of serum concentrations of inflammatory cytokines in individuals with 22q11DS, providing a basis for further inquiry.     

Parental adjustment,parenting attitudes and emotional and behavioral problems in children with selective mutism

The present study investigated emotional and behavioral problems in children with selective mutism (SM) along with the psychological adjustment and parenting attitudes of their mothers and fathers. Participants included 26 children with SM (mean age = 8.11 ± 2.11 years), 32 healthy controls (mean age = 8.18 ± 2.55 years) and the parents of all children. Children with SM displayed higher problem scores than controls in a variety of emotional and behavioral parameters. They predominantly displayed internalizing problems, whereas aggressive and delinquent behavior was described among a subsample of the children. Significant differences existed between the SM and control groups only in paternal psychopathology, which included anxiety and depression. They did not differ with respect to maternal psychological distress or mother or father reported parental attitudes. Another important result of the present study was that the severity of emotional and behavioral problems of children with SM was correlated with maternal psychopathology but not paternal psychopathology.     

Severity of depressive symptomatology and functional impairment in children and adolescents with temporal lobe epilepsy

ObjectiveDepression is a frequent psychiatric disorder in children with temporal lobe epilepsy (TLE). However, severity of depressive symptoms (DS) is frequently neglected in these patients. This study aimed to determine severity of DS and global functioning by using quantitative measures and to establish their correlation with patients’ demographics and clinical variables.Methods31 children (mean age of 11.8 ± 2.3 years) with TLE were assessed with K-SADS-PL for axis I DSM-IV diagnosis. Severity of DS was measured by Children Depression Rating Scale-Revised – CDRS-R. Global functional impairment was evaluated with Child Global Assessment Scale-CGAS.Results25 patients (56% boys; 12 ± 2.3 years) had current DS, moderate or severe in 84% according to CDRS-R T-Score. Severity of DS was not correlated with age (p = 0.377), gender (p = 0.132), seizure control (p = 0.936), age of onset (p = 0.731), duration of epilepsy (p = 0.602) and the presence of hippocampal sclerosis (p = 0.614). Patients had moderate to major functional impairment measured by CGAS (48.7 ± 8.8), being adolescents more impaired than children (p = 0.03). Impairment of global functioning was not associated with epilepsy variables (p > 0.05).ConclusionChildren with TLE had moderate to severe DS early in the course of their disease with a relevant impact on their global functional activities, especially considering adolescents. Epilepsy severity seems not to be correlated to the severity of DS, contradicting the idea of a cause–consequence relationship. More systematic research is needed to better understand the association of depressive disorders in children and adolescents with TLE.     

Early screening and identification of psychological comorbidities in pediatric epilepsy is necessary

Youth with epilepsy often have co-occurring psychological symptoms that are due to underlying brain pathology, seizures, and/or antiepileptic drug side effects. The primary study aim was to compare the psychological comorbidities of youth with new-onset epilepsy versus chronic epilepsy. Primary caregivers of youth with either new-onset (n = 82; M_age = 9.9 ± 2.9) or chronic epilepsy (n = 76; M_age = 12.8 ± 3.3) completed the Behavioral Assessment Scale for Children—2nd Edition. Compared to those with new-onset epilepsy, the chronic group had significantly higher depressive and withdrawal symptoms, as well as lower activities of daily living. A higher proportion of youth with chronic epilepsy exhibited at-risk/clinically elevated depressive symptoms and difficulties with activities of daily living compared to the new-onset group. Proactive screening in youth with epilepsy to ensure timely identification of psychological symptoms and to guide early psychological intervention is warranted.     

Virtual reality as means to improve physical fitness of individuals at a severe level of intellectual and developmental disability

Individuals with intellectual and developmental disabilities (IDD) are in need of effective and motivating physical fitness training programs. The aim was to test the effectiveness of a virtual reality (VR)-based exercise program in improving the physical fitness of adults with severe IDD when implemented by on-site caregivers. A research group (N = 20; mean age ± standard deviation = 47.9 ± 8.6 years; severe IDD level) was matched for age, IDD level and functional abilities with a comparison group (N = 24, mean age = 46.2 ± 9.3 years; severe IDD level). An 8-week fitness program consisting of 2–3 30-min sessions per week included game-like exercises provided by the IREX/GX video capture VR system. Changes in physical fitness were monitored by changes in heart rate at rest. A significant (P < 0.005) reduction in heart rate was demonstrated for the research group. No change in heart rate was monitored in the comparison group. Despite statistically significant improvements in heart rate, the results are not strong enough functionally to claim that this program improved physical fitness of individuals with severe intellectual disability.     

Test–retest reliabilities of hand-held dynamometer for lower-limb muscle strength in intellectual disabilities

The primary purpose of this study was to investigate the test–retest reliabilities of hand-held dynamometer (HDD) for measuring lower-limb muscle strength in intellectual disabilities (ID). The other purposes were to: (1) compare the lower-limb muscle strength between children with and without ID; (2) probe the relationship between the muscle forces and agility performance in ID; and (3) explore the factors associated with muscle strength in ID.Sixty-one participants (30 boys and 31 girls; mean age = 14.1 ± 3.3 year) were assessed by the HDD using a “make” test. The comparative group consisted of 63 typically developing children (33 boys and 30 girls; mean age = 14.9 ± 2.1 year). The ID group demonstrated lower muscle groups than in typically developing group. Except for the ankle plantarflexors (ICC = 0.69, SEM = 0.72), test–retest analysis showed good intrarater reliability with ICC ranging from 0.81 to 0.96, and intrarater SEM values ranged from 0.40 to 0.57. The HDD has the potential to be a reliable tool for strength measurement in ID. Muscle strength was positively related to agility performance. Regression analysis indicated that height, weight, BMI, and activity level were significant predictors of muscle strength in ID.     

Cognitive and adaptive evaluation of 21 consecutive patients with Dravet syndrome

In order to assess the cognitive and adaptive profiles of school-aged patients with Dravet syndrome (DS), we proposed to evaluate the intelligence and adaptive scores in twenty-one 6- to 10-year-old patients with DS followed in our institution between 1997 and 2013. Fourteen patients were tested using the Wechsler Intelligence Scale for Children (WISC) and the Vineland Adaptive Behavioral Scales (VABS); 6 patients could not be tested with the WISC and were tested with the VABS only, and one was tested with the WISC only. Data regarding the epilepsy were retrospectively collected. Statistical analysis (Spearman rank order and Pearson correlation coefficient) was used to correlate early epilepsy characteristics with the cognitive and adaptive scores.Sodium channel, neuronal alpha-subunit type 1 (SCN1A) was mutated in 19 out of 21 patients. After the age of 6 years, none of the DS patients had a normal intelligence quotient (IQ) using WISC (age at the testing period: mean = 100 ± 5; median = 105 months; mean total IQ = 47 ± 3; n = 15). Only five patients had a verbal and/or a non verbal IQ of more than 60 (points). Their cognitive profile was characterized by an attention deficit, an inability to inhibit impulsive responses, perseverative responses and deficit in planning function. Administering the Vineland Adaptive Behavioral Scales in the same period, we showed that socialization skills were significantly higher than communication and autonomy skills (age at the testing period: mean = 100 ± 4; median = 100 months; n = 20).We did not find any significant correlation between the IQ or developmental quotient assessed between 6 and 10 years of age and the quantitative and qualitative parameters of epilepsy during the first two years of life in this small group of patients.Despite an overall moderate cognitive deficit in this group of patients, the Vineland Adaptive Behavioral Scales described an adaptive/behavioral profile with low communication and autonomy capacities, whereas the socialization skills were more preserved. This profile was different from the one usually found in young patients with autism and may require specific interventions.     

Visual-motor integration,visual perception,and fine motor coordination in a population of children with high levels of Fetal Alcohol Spectrum Disorder

BackgroundVisual-motor integration (VMI) skills are essential for successful academic performance, but to date no studies have assessed these skills in a population-based cohort of Australian Aboriginal children who, like many children in other remote, disadvantaged communities, consistently underperform academically. Furthermore, many children in remote areas of Australia have prenatal alcohol exposure (PAE) and Fetal Alcohol Spectrum Disorder (FASD), which are often associated with VMI deficits.MethodsVMI, visual perception, and fine motor coordination were assessed using The Beery-Buktenica Developmental Test of Visual-Motor Integration, including its associated subtests of Visual Perception and Fine Motor Coordination, in a cohort of predominantly Australian Aboriginal children (7.5–9.6 years, n = 108) in remote Western Australia to explore whether PAE adversely affected test performance. Cohort results were reported, and comparisons made between children i) without PAE; ii) with PAE (no FASD); and iii) FASD. The prevalence of moderate (≤16th percentile) and severe (≤2nd percentile) impairment was established.ResultsMean VMI scores were ‘below average’ (M = 87.8 ± 9.6), and visual perception scores were ‘average’ (M = 97.6 ± 12.5), with no differences between groups. Few children had severe VMI impairment (1.9%), but moderate impairment rates were high (47.2%). Children with FASD had significantly lower fine motor coordination scores and higher moderate impairment rates (M = 87.9 ± 12.5; 66.7%) than children without PAE (M = 95.1 ± 10.7; 23.3%) and PAE (no FASD) (M = 96.1 ± 10.9; 15.4%).ConclusionsAboriginal children living in remote Western Australia have poor VMI skills regardless of PAE or FASD. Children with FASD additionally had fine motor coordination problems. VMI and fine motor coordination should be assessed in children with PAE, and included in FASD diagnostic assessments.     

Physical fitness in children with Developmental Coordination Disorder: Measurement matters

Children with Developmental Coordination Disorder (DCD) experience considerable difficulties coordinating and controlling their body movements during functional motor tasks. Thus, it is not surprising that children with DCD do not perform well on tests of physical fitness. The aim of this study was to determine whether deficits in motor coordination influence the ability of children with DCD to perform adequately on physical fitness tests. A case–control study design was used to compare the performance of children with DCD (n = 70, 36 boys, mean age = 8y 1mo) and Typically Developing (TD) children (n = 70, 35 boys, mean age = 7y 9mo) on measures of isometric strength (hand-held dynamometry), functional strength, i.e. explosive power and muscular endurance (Functional Strength Measurement), aerobic capacity (20 m Shuttle Run Test) and anaerobic muscle capacity, i.e. muscle power (Muscle Power Sprint Test). Results show that children with DCD were able to generate similar isometric forces compared to TD children in isometric break tests, but were significantly weaker in three-point grip strength. Performance on functional strength items requiring more isolated explosive movement of the upper extremities, showed no significant difference between groups while items requiring muscle endurance (repetitions in 30 s) and items requiring whole body explosive movement were all significantly different. Aerobic capacity was lower for children with DCD whereas anaerobic performance during the sprint test was not. Our findings suggest that poor physical fitness performance in children with DCD may be partly due to poor timing and coordination of repetitive movements.     

Atención sostenida en niños con hipotiroidismo congénito en edad escolar. Influencia de los episodios de sobretratamiento en los primeros 3 años de vida

IntroductionChildren with congenital hypothyroidism (CH) are at risk of developing mild cognitive impairment despite normal overall intellectual performance. These deficits may be caused by disease-related and treatment-related factors. This study explores the impact of abnormal thyroid function during the first 3 years of life on attention performance at school age.MethodsWe included 49 children diagnosed with CH and receiving treatment for the condition: 14 boys (mean age 9.5 ± 2.8 years) and 35 girls (9.6 ± 2.6 years). The number of episodes of normal, under-, and overtreatment were estimated based on TSH levels during their first 3 years of life (at 12, 18, 24, 30, and 36 months). Children were assessed using a computerised version of a Sustained attention test. General linear models were calculated with the attention index as the dependent variable and sex, aetiology, and number of episodes of normal, under-, and overtreatment as independent variables.ResultsHigher numbers of episodes of overtreatment (low TSH level) were associated with poorer attention performance at school age (P = .005, r = –0.45).ConclusionsChildren with CH should be monitored closely during the first 3 years of life in order to prevent not only hypothyroidism but also any adverse effects of overtreatment that may affect attentional function at school age.     

Evaluation of health-care utilization in patients with Dravet syndrome and on adjunctive treatment with stiripentol and clobazam

Dravet syndrome (DS) is a rare, severe childhood epilepsy syndrome that imposes a substantial burden on patients and their caregivers. This study evaluated health-care utilization over a 2-year period in patients with DS at an outpatient clinic of a German epilepsy center. Data on the course of epilepsy, anticonvulsant treatment, and direct costs were recorded using the electronic seizure diary Epivista® and patients' files.We enrolled 13 patients with DS (6 females, mean age: 12.3 ± 7.5 years) between 2007 and 2010 and evaluated them during a 1-year baseline. All patients had drug-resistant epilepsy and their seizures failed to improve with a mean number of 6.7 ± 3.4 anticonvulsants. They had an overall mean seizure frequency of 102.1 seizures per year (median: 31, range: 3–538) with 43.2 GTCSs per year (median: 14, range: 0–228). We estimated the annual total direct costs at €6506 ± 3974 (range: €1174–11,783) per patient with hospitalization (68.9% of total direct costs) as the major cost factor ahead of costs for anticonvulsants (24.0%). For the 1-year follow-up period, less severely affected patients were continued on conventional anticonvulsants (n = 4) or switched to adjunctive treatment with stiripentol and clobazam (n = 9). In the latter group, six patients (67%) were long-term responders, with between 25% and 100% seizure reduction with respect to either GTCSs or the overall seizure frequency. This reduction in seizure frequency was associated with a shift in the distribution of cost components towards higher medication costs and decreased hospitalization costs. The total direct costs increased by 42.7%, mainly due to the newly introduced stiripentol, with an annual cost of €6610.This study showed that direct costs of patients with DS were above the average European costs of drug-resistant epilepsy in children. Treatment with new anticonvulsants resulted in reduction of seizures and inpatient admissions.     

Developmental Coordination Disorder in children with specific language impairment: Co-morbidity and impact on quality of life

Co-morbidity of Developmental Coordination Disorder (DCD) in children with specific language impairment (SLI) and the impact of DCD on quality-of-life (QOL) was investigated in 65 5–8 year old children with SLI (43 boys, age 6.8 ± 0.8; 22 girls, age 6.6 ± 0.8). The prevalence of DCD was assessed using DSM-IV-TR criteria (American Psychiatric Association (APA), 2000) operationally defined in the clinical practice guideline (CPG): movement ABC scores below 15th percentile, scores on DCDQ and/or MOQ-T below 15th percentile, absence of medical condition according to paediatric-neurological exam. Quality of life (QOL) was measured with the TNO-AZL-Child-Quality-Of-Life (TACQOL) Questionnaire filled out by parents for the SLI group with and without DCD, and compared to a reference group (N = 572; age 6.9 ± 0.9). The TACQOL covers 7 QOL domains: physical, motor, cognitive and social functioning, autonomy, positive and negative moods. Prevalence of DCD in children with SLI was 32.3%. In children with SLI, mean QOL scores were significantly lower in the autonomy, cognitive, social and positive moods domains compared to the reference group. Children with SLI and DCD differed from children with SLI without DCD by significantly lower mean overall-, motor-, autonomy-, and cognitive domain-QOL scores. Clinicians should be aware that about one third of children with SLI can also be diagnosed with DCD. Assessment of QOL is warranted in order to assess which domains are affected in children with SLI with or without DCD.     

Cognitive and behavioral trajectories in 22q11DS from childhood into adolescence: A prospective 6-year follow-up study

Patients with 22q11DS are at risk of behavioral problems and cognitive impairment. Recent studies suggest a possible intellectual decline in 22q11DS children. To date it is unknown if cognitive development is related to the behavioral problems in 22q11DS. We studied 53 children with 22q11DS who underwent cognitive and behavioral assessments at 9.5 years (T1) and 15.3 years (T2). In about one third, IQ data obtained at 7.5 years (T0) were also available. Results showed that internalizing behaviors intensified while externalizing behaviors decreased. Simultaneously, in about a third a significant decline in IQ was found, which, surprisingly, was unrelated to the behavioral changes. It can be concluded that children with 22q11DS follow a unique developmental trajectory. Cognitive deterioration is severe in some but does not appear to predict behavioral problems in early adolescence.     

The bone tissue of children and adolescents with Down syndrome is sensitive to mechanical stress in certain skeletal locations: A 1-year physical training program study

The systemic complications of Down syndrome (DS) attenuate the osteogenic response to physical activity in DS patients. Through an interventional study we showed the effects of physical training on development of bone mineral content (BMC) and density (BMD) as well as on quantitative bone ultrasound (QUS) parameters in individuals with DS. A total of 42 children with DS were randomly assigned to either an exercising (DS-E, n = 20, age 16 ± 1.8 years) or non-exercising group (DS-NE, n = 22, age 16.9 ± 1.5 years). DS-E group was assigned to a program of osteogenic activities with 60 min sessions twice a week, over 12 month period. Bone mass measures were performed by dual X-ray absorpsiometry (DXA) at the spine and hip, and ultrasound attenuation (BUA) and velocity (SOS) assessed from the calcaneus by QUS device. All bone parameters had evolved with age, except for neck BMD. One year of training increased BMC values at lumbar spine (7%, p < .005) and total hip (10%, p < .05), and BMD values only at lumbar spine (4%, p < .05). Changes in BUA and SOS values were not evident following training. Trained individuals increased their motor skills measured through Eurofit tests.It was concluded that a program of osteogenic physical training may induce bone improvement in children with DS, but with a lower magnitude than that reported in the specialized literature for individuals without DS.     

Disturbed dreaming during the third trimester of pregnancy

ObjectiveThe majority of women develop sleep impairments during pregnancy, but alterations in dream experiences remain poorly understood. This study aimed to assess prospectively and comparatively the recall of dreaming and of disturbed dreaming in late pregnancy.MethodsFifty-seven nulliparous, third-trimester pregnant women (mean age ± SD, 28.7 ± 4.06 years) and 59 non-pregnant controls (mean age ± SD, 26.8 ± 4.21 years) completed demographics and psychological questionnaires. A 14-day prospective home log assessed sleep and dream characteristics and the Sleep Disorders Questionnaire measured retrospective dream and disturbed dream recall.ResultsEven though pregnant and non-pregnant women showed similar prospective dream recall (P = 0.47), pregnant women reported prospectively more bad dreams (P = 0.004). More pregnant women (21%) than non-pregnant women (7%) reported a nightmare incidence exceeding moderately severe pathology (>1/week) (P = 0.03). Pregnant women also reported overall lower sleep quality (P = 0.007) and more night awakenings (P = 0.003). Higher prospective recall of bad dreams (r = −0.40, P = 0.002) and nightmares (r = −0.32, P = 0.001) both correlated with lower sleep quality in pregnant women.ConclusionsLate pregnancy is a period of markedly increased dysphoric dream imagery that may be a major contributor to impaired sleep at this time. Further polysomnographic assessments of pregnant women are needed to clarify relationships between sleep and disturbed dream production in this population.     

Arterial stiffness response to exercise in persons with and without Down syndrome

This study compared arterial stiffness and wave reflection at rest and following maximal exercise between individuals with and without Down syndrome (DS), and the influence of body mass index (BMI), peak oxygen uptake (VO₂peak) on changes in arterial stiffness. Twelve people with DS (26.6 ± 2.6 yr) and 15 healthy controls (26.2 ± 0.6 yr) completed this study. Intima-media thickness (IMT) and stiffness of common carotid artery was examined. Hemodynamic and arterial variables were measured before and 3-min after exercise. Persons with DS had higher BMI and lower VO₂peak than controls. IMT did not differ between groups. At rest, carotid β stiffness was significantly higher in persons with DS (P < 0.05) but there was no difference in between groups for any of the other arterial stiffness measures. After exercise, persons with DS exhibited attenuated arterial stiffness responses in AIx-75, carotid β stiffness and Ep in contrast with controls (significant group-by-time interactions). When controlling for BMI and VO₂peak, the interactions disappeared. In both groups combined, BMI was correlated significantly with carotid Ep and β at rest. VO₂peak correlated significantly with AIx-75 and its pre-post change (r = ?0.45, P = 0.029; r = 0.47, P = 0.033, respectively). The arterial stiffness responses to maximal exercise in persons with DS were blunted, potentially reflecting diminished vascular reserve. Obesity and particularly VO₂peak influenced these findings. These results suggest impaired vascular function in people with DS.