Increased Risk of Myofascial Pain Syndrome Among Patients with Insomnia.
OBJECTIVE
The aim of this study is to evaluate the risk of developing myofascial pain syndrome among patients diagnosed with insomnia.


METHODS
We conducted a population-based longitudinal study of a matched cohort with 7,895 participants (1,579 patients with insomnia and 6,316 controls) who were selected from the Taiwan National Health Insurance Research Database. The patients were observed for a maximum of 10 years to determine the incidence of newly diagnosed myofascial pain syndrome. A Cox regression analysis was performed to identify the risk factors associated with myofascial pain syndrome in patients with insomnia.


RESULTS
During the 10-year follow-up period, 182 insomnia patients (14.9 per 1,000 person-years) and 379 controls (7.5 per 1,000 person-years) were diagnosed with myofascial pain syndrome. The incidence risk ratio of myofascial pain syndrome between the insomnia and control patients was 2.00 (95% confidence interval [CI] = 1.67-2.38, P  < 0.001). After adjusting for age, sex, monthly income, urbanization, and comorbidities, the insomnia patients were 1.93 times more likely to develop myofascial pain syndrome (95% CI = 1.62-2.31, P  < .001) than the control patients. Malignant neoplasm (hazard ratio = 3.08) and living in urban areas (hazard ratio = 3.05) were identified as independent risk factors for myofascial pain syndrome in patients with insomnia.


CONCLUSIONS
Patients with insomnia had a higher risk of developing myofascial pain syndrome than controls. This study adds to the understanding of the complex relationship between sleep disturbance and pain.
Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan.|Division of Psychiatry, Faculty of Medicine.|Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.
Wei-Chen
WC
Lin
Division of Psychiatry, Faculty of Medicine.|Department of Psychiatry, Chiayi Branch, Taichung Veterans General Hospital, Chiayi, Taiwan.|Department of Information Management, National Chung-Cheng University, Chiayi, Taiwan.
Cheng-Che
CC
Shen
Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan.|Division of Psychiatry, Faculty of Medicine.
Shih-Jen
SJ
Tsai
Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan.|Division of Psychiatry, Faculty of Medicine.|Center for Dynamical Biomarkers and Translational Medicine, National Central University, Chungli, Taiwan.
Albert C
AC
Yang
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009209:Myofascial Pain Syndromes / Q000453:epidemiology*; D016016:Proportional Hazards Models; D007319:Sleep Initiation and Maintenance Disorders / Q000150:complications*; D013624:Taiwan / Q000453:epidemiology
Epidemiology; Fibromyalgia; Insomnia; Myofascial Pain; Risk Factor