Background Fibromyalgia (FM) is a chronic pain disorder characterized by widespread pain, tenderness, and various associated symptoms including sleep disturbances, chronic fatigue, depression, and other somatic symptoms. Several longitudinal and cross-sectional studies in western countries have shown that a high body mass index (BMI) is a strong and independent risk factor for future development of FM and is associated with higher levels of FM symptoms. In addition, obese patients have more physical and emotional impairments compared with nonobese patients.
Objectives The purpose of this study was to determine whether obesity and socioeconomic factors influence symptom severity in Korean patients with FM.
Methods A total of 343 patients with FM were recruited from outpatient clinics at 11 medical centers across the Republic of Korea. All patients met the ACR 1990 classification criteria for FM. We interviewed these patients using a structured questionnaire that included sociodemographic data, current or past FM symptoms, and current use of relevant medications at the time of enrollment. Tender point counts and scores were assessed by thumb palpation. Patients were asked to complete a Korean version of the Fibromyalgia Impact Questionnaire (FIQ), the Brief Fatigue Inventory (BFI), the SF-36, the Beck Depression Inventory (BDI), the State-Trait Anxiety Inventory (STAI), the Self-Efficacy Scale, and the Social Support Scale.
Results Based on an obesity definition of a BMI of ≥25, 76 (22.1%) of the 343 patients were obese. Obese patients were not different from nonobese patients in terms of tender points and scores, FIQ, BFI, SF-36, BDI, STAI, Self-Efficacy, and Social Support scores. After age-, gender-, and symptom duration adjustment by propensity score matching, no significant differences were also found between obese and nonobese patients. However, socioeconomic status such as employment, insurance, and education were significantly associated with symptom severity of FM. The unemployed patients had higher FIQ scores (p=0.011), higher BFI scores (p=0.013), lower physical and mental component SF-36 scores (p=0.012, p=0.005), higher BDI scores (p=0.005), and higher STAI II scores (p=0.041). Lower-income patients had higher FIQ score (p=0.040), lower physical and mental SF-36 scores (p=0.047, p=0.006), higher BDI scores (p<0.000), and lower Self-Efficacy scores (p=0.016). Finally, patients with an education of <12 years had higher tender points (p=0.034), higher BDI scores (p=0.007), and higher STAI II scores (p=0.045).
Conclusions Our findings show that, contrary to Western patients, symptom severity in Korean patients with FM is associated with socioeconomic status, but not with obesity.
Disclosure of Interest : None declared