Nic Waals Institute, Lovisenberg Diaconal Hospital, Oslo, Norway.
Norwegian Institute of Public Health, Oslo, Norway.
J Child Psychol Psychiatry. 2021 Sep;62(9):1070-1078. doi: 10.1111/jcpp.13369. Epub 2020 Dec 28.
Delayed walking is common in intellectual disability (ID) but may be less common when ID occurs with autism spectrum disorder (ASD). Previous studies examining this were limited by reliance on clinical samples and exclusion of children with severe motor deficits.
To examine in a population-based sample if age of walking is differentially related to intellectual ability in children with ASD versus other neurodevelopmental disorders (NDD).
Participants were from the nested Autism Birth Cohort Study of the Norwegian Mother, Father and Child Cohort Study (MoBa). Cox proportional hazards regression assessed if diagnosis (ASD n = 212 vs. NDD n = 354), continuous nonverbal IQ, and their interaction, were associated with continuous age of walking.
The relationship between nonverbal IQ and age of walking was stronger for NDD than for ASD (Group × nonverbal IQ interaction, χ = 13.93, p = .0002). This interaction was characterized by a 21% decrease in the likelihood of walking onset at any given time during the observation period per 10-point decrease in nonverbal IQ (hazard ratio = 0.79, 95% CI: 0.78-0.85) in the NDD group compared to 8% (hazard ratio = 0.92, 95% CI: 0.86-0.98) in the ASD group.
The finding that age of walking is less strongly related to low intellectual ability in children with ASD than in children without other NDDs supports the hypothesis that ID in ASD may result from heterogeneous developmental pathways. Late walking may be a useful stratification variable in etiological research focused on ASD and other NDDs.
智力障碍（ID）患者常出现行走延迟，但当 ID 合并自闭症谱系障碍（ASD）时，这种情况可能较少见。之前的研究因依赖临床样本和排除严重运动障碍儿童而受到限制。
在基于人群的样本中，检查 ASD 患儿与其他神经发育障碍（NDD）患儿的行走年龄是否与智力能力存在差异。
参与者来自挪威母婴队列研究（MoBa）中的自闭症出生队列嵌套研究。Cox 比例风险回归评估了诊断（ASD n=212 与 NDD n=354）、连续非言语智商以及它们的交互作用是否与连续行走年龄相关。
非言语智商与行走年龄的关系在 NDD 中比在 ASD 中更强（组×非言语智商交互作用，χ²=13.93，p=0.0002）。这种交互作用的特征是，在观察期间的任何给定时间，非言语智商每降低 10 分，NDD 组行走起始的可能性降低 21%（风险比=0.79，95%CI：0.78-0.85），而 ASD 组降低 8%（风险比=0.92，95%CI：0.86-0.98）。
与没有其他 NDD 的 ASD 患儿相比，ASD 患儿的行走年龄与智力能力的相关性较弱，这一发现支持了 ASD 中的 ID 可能源于异质发育途径的假设。行走延迟可能是针对 ASD 和其他 NDD 的病因学研究中有用的分层变量。
