The association between insomnia and musculoskeletal problems in employees of an automotive company in Tehran, Iran

Objectives: The purpose of this study was to examine the association between insomnia and the number of pain areas among employees of an automotive company. Secondary aim was to examine the association between depression, anxiety, and stress, and musculoskeletal pain independent of insomnia. Material and methods: We performed a cross-sectional study conducted in an automobile manufacturing factory. To collect data, we used the Nordic Musculoskeletal Questionnaire, ISI (Insomnia Severity Index), and DASS-21 (Depression, Anxiety, and Stress Scale). The univariate and multiple association analyses were performed using ordinal logistic regression adjusted for gender, age, industrial/non-industrial, sport activity, pack year, educational level, years of employment, anxiety, stress, and depression. Result: In individuals with insomnia, the lower back was the most common area where pain was reported (59.5%). In all areas, pain symptoms were significantly more prevalent in individuals with insomnia compared to those without insomnia. Insomnia was associated with having pain with an increased odds of number of pain sites (odds ratio [OR] 2.81,95%CI 2.34-3.39). In ordinal logistic regression, there was an association between insomnia and pain, independent of the effects of depression, anxiety, and stress (OR 2.21,95%CI 1.52-3.23). Discussion: Insomnia was associated with pain in all regions of the body and a higher prevalence of pain in multiple areas. The insomnia-pain association was independent of depression, anxiety, and stress.