Objectives: To elucidate the association between metabolic syndrome (MetS) and disability due to low back pain (LBP) among care workers. Material and Methods: This cross-sectional study enrolled 656 care workers having experienced LBP in the year prior to the year of this study. The Roland-Morris Disability questionnaire (RDQ) and self-reported questionnaires regarding LBP, fear of movement, depressive symptom, psychosocial factors, intensity of pain, and duration of pain were administered, and a medical examination was performed. Metabolic syndrome was defined according to the international definition agreed in 2009. Out of the 656 care workers, we included 316 care workers (response rate: 48.2%) who had fully completed the questionnaires as the study sample (males: 13.6%, median age = 51 years old, range: 35-74 years old). To examine the association between MetS and the level of disability due to LBP, we used the Poisson regression analysis and estimated crude and adjusted prevalence ratios (PR). Results: Out of the 316 care workers, 52 (16.5%) were diagnosed as having MetS. Metabolic syndrome was significantly associated with the RDQ score (adjusted PR: 1.57, 95% confidence interval (CI): 1.17-2.11) after adjusting for covariates, such as age, sex, fear of movement, job demands, social support, intensity of pain, and duration of pain. Conclusions: This study showed that MetS was independently associated with disability due to LBP among care workers. A multidisciplinary intervention taking MetS into consideration may be an effective way to reduce disability due to LBP in people with both LBP and MetS.
MATERIAL AND METHODS
Study populationsA cross-sectional survey was conducted from January 2014 to March 2014. We distributed self-reported questionnaires to 954 care workers employed by a Japanese company providing senior care services and performed their medical examination. We included 656 care workers (68.8%) who had experienced LBP in the year prior to this study. Ethical approval for this study was given by the Ethics Committee of Kobe University Graduate School of Health Sciences. By completing the questionnaires, the participants indicated their consent to participation. The protocol number of approval of this study is 336-1.
MeasurementsData on demographics and health status was collected from the results of the medical examination. Self-reported questionnaires were designed to collect information on the level of disability due to LBP, the details of the LBP, MetS, physical workload, fear of movement, depressive symptom, and psychosocial factors. A Japanese version of the Roland-Morris Disability Questionnaire (RDQ) [14] was used for assessing disability in those having experienced LBP in the previous year. The RDQ is a validated and reliable instrument for assessing disability due to LBP [14]. It includes 20 items concerning limitations due to LBP in different daily life activities and 4 items concerning pain, sleep, appetite and emotional functions. Each item is scored either 0 or 1, with all t...