Prediction of antioxidant capacity, age, and sex on sleep impairment in patients with amyotrophic lateral sclerosis

Abstract

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterised by high levels of inflammation and oxidative stress, predominantly affecting males, particularly those between the ages of 50 and 65 years. It is characterised by progressive loss of motor neurones, leading to both motor and non-motor symptoms, such as sleep impairment, diagnosed in most patients, which adversely affects their quality of life. Therefore, this study aimed to determine the predictive role of antioxidant capacity, psychological distress, age, and sex on sleep impairment in an adult population of patients with ALS. A descriptive, quantitative, cross-sectional study was conducted using a sample of 74 patients diagnosed with bulbar or spinal ALS. To assess sleep disturbances in these patients, the Pittsburgh sleep quality index (PSQI), epworth sleepiness scale (ESS), and Insomnia severity index were used. Additionally, plasma antioxidant capacity was analysed using the total antioxidant capacity (TEAC), Cupric Ion reducing antioxidant capacity (CUPRAC), and ferric reducing power (FRAP). Anxiety and depression measures were used to measure psychological distress. Men exhibited a higher antioxidant status (lower oxidative stress) than women, and higher antioxidant capacity was associated with fewer sleep impairments (β = −0.43). Psychological distress may increase sleep impairment (β = −0.26). Furthermore, older individuals experienced less sleep impairment (β = −0.27), while sex had minimal influence on sleep deterioration, although it appears that men had fewer disturbances (β = −0.12). Having a higher antioxidant status, lower psychological distress, being male, and being older seem to act as predictors of reduced sleep impairment in ALS. Specifically, these four predictors account for 32% of sleep deterioration. Clínical trial registration: The present descriptive, quantitative, cross-sectional study was part of a clinical trial involving ALS patients, registered under the number NCT04654689 (https://clinicaltrials.gov/study/NCT04654689#wrapper).