Association of urinary arsenic and sleep disorder in the US population: NHANES 2015–2016

Arsenic is a known carcinogen and neurotoxin and is found in the natural earth crust. Arsenic exposure can develop depression, memory dysfunction, and neurodegenerative disorder. The mechanism of arsenic toxicity on the nervous system is not known. There is a lack of research on the association between arsenic exposure and sleep disturbance in humans. This study aims to investigate the relationship between six types of urinary speciated arsenic exposure and sleep disturbance in adults from the general population using the National Health and Nutrition Examination Survey (NHANES) 2015-2016 dataset. Sleep disturbance was measured using self-reported questionnaires, asking participants if they had ever told a doctor they had trouble sleeping. We utilized multivariate logistic regression analysis using complex survey procedures to examine the association between six types of urinary arsenic concentration and trouble sleeping. The total sample included 1,611 adults who were 20 years and older. Of the study participants, 30.0% had trouble sleeping. Compared to individuals with urinary arsenous acid below the lower level of detection (LLOD), those with urinary arsenous acid at or above the detection limit had lower odds of trouble sleeping [odds ratio: 0.72 (95% confidence interval 0.51-1.00, p-value: 0.05)]. The other five types of urinary speciated arsenic studied (arsenic acid, arsenobetaine, arsenocholine, dimethylarsinic acid, monomethylarsonic acid) were not associated with a sleep disorder. More studies are required to confirm or refute these findings.