Características de la respuesta a estímulos sensoriales y alteraciones gastrointestinales en personas con trastorno del espectro autista

Laburpena

Background. People with autism spectrum disorder (ASD) often present with gastrointestinal symptoms that can interfere with their quality of life. Alterations in the microbiota-gut-brain axis have been related to sensory reactivity, pain, and the presence of gastrointestinal symptoms in ASD. To better understand the impact of these symptoms, a measure is needed that meets the Rome IV criteria and is applicable to the ASD population. The Gastrointestinal Symptoms Severity Scale, GSSS, is a new assessment tool designed to meet this need. Methods. The objective of this thesis was to analyze the psychometric properties of the GSSS, through two studies: study 1 with a sample of 265 people with ASD ((mean age = 9.44, SD = 4.99) and study 2 composed of a sample of 1247 neurotypical adolescents (mean age=: 22.17 years, SD =7.19), an exploratory factor analysis (EFA), a confirmatory factor analysis (CFA), analysis of internal consistency, and test-retest reliability were performed. , the invariance of the measurement depending on sex, and the convergent and discriminant validity for the sample of people with ASD and neurotypicals. In the same way, the percentiles of both populations were calculated. Results. In relation to study 1, around 30.9% of participants evidenced clear difficulties with gastrointestinal symptoms, and these symptoms were strongly associated with more severe ASD features, greater sensory reactivity, and increased repetitive behaviors. On the other hand, in the neurotypical sample it was found that 23% had diarrhea, 19.7% had nonspecific abdominal pain, 10.6% had dyspepsia, and 11% had gastroesophageal reflux. The EFA found a two-factor structure with a moderate percentage of explained variance (51.3%), and subsequently, the CFA confirmed a good fit of the items for a single factor of the scale in both the ASD and neurotypical samples. The GSSS showed adequate internal consistency, test-retest reliability and convergent validity. Conclusions. The GSSS presents acceptable psychometric properties to be used both in the ASD population, with the informant being caregivers, and in neurotypical adolescents and young adults. It may be a promising measure to analyze the prevalence, severity and impact of gastrointestinal symptoms in individuals with ASD and in the general population. Likewise, a useful instrument for analyzing the gut-brain axis.