Background Fibromyalgia (FM) is a clinical condition characterized by chronic widespread pain associated with symptoms such as fatigue, waking unrefreshed, depression. Several studies reported a relationship between high body mass index (BMI) and painful syndromes such as FM, but the real impact of a high BMI on clinical severity in patients with FM is still unclear. Furthermore, FM is characterized by a neuropathic component of pain. Obesity and overweight seem to get worse the intensity of neuropathic pain.

Objectives The aim of this study was to evaluate the relationships between BMI categories and FM related symptoms, investigating fatigue, neuropathic pain, depression and sleep disorders.

Methods We analyzed a cohort of 419 patients (M 15/ F 404, median age 56), with a diagnosis of FM according to the 2016 ACR criteria. The participants were consecutively recruited from the Fibromyalgia clinic of the University of Campania “Luigi Vanvitelli”. All patients were stratified into three groups according to BMI categories: normal weight (18,5-24,9), overweight (25,0-29,9) and obesity (>30,0). We assessed fatigue by Functional Assessment of Chronic Illness Therapy-Fatigue Subscale (FACIT-F), neuropathic pain by PainDETECT Questionnaire (PDQ), depression by Patient Health Questionnaire-9 (PHQ-9) and sleep disorders by Pittsburgh Sleep Quality Index (PSQI).

Prism GraphPad software was used; the level of significance was set at p < 0.05.

Results Total patient population (n=419) had a mean BMI 26,64 (SD 5,768); all patients showed fatigue (100%) with a mean FACIT-F score 23,01 (SD 10,15); we found neuropathic pain (PDQ>20) in 301 patients (71,83%) with a mean PDQ score 22,95 (SD 8,935); 52 patients (12,41%) had no depression (PHQ-9 <4), 68 patients (16,23%) showed a mild depression (PHQ-9 10-14), 121 patients (28,88%) a moderate depression (PHQ-9 15-19) and 140 patients (33,41%) a severe depression (PHQ-9 ≥20) with a mean PHQ-9 score 15,53 (SD 7,704); sleep disorders were found in 360 patients (85,91%) with a mean PSQI score 11,28 (SD 6,117). 155 (37%) normal weight patients (mean BMI 22,13) (SD 1,672) had a mean FACIT-F score 20,14 (SD 10,52), a mean PDQ score 17,93 (SD 9,740), a mean PHQ-9 score 11,62 (SD 8,266) and a mean PSQI score 8 (SD 6,330); 161 overweight patients (38,4%) (mean BMI 27,15) (SD 1,400) had a mean FACIT-F score 22,64 (SD 9,983), a mean PDQ score 24,33 (SD 7,831), a mean PHQ-9 score 15,54 (SD 6,809) and a mean PSQI score 11,57 (SD 4,978); 103 obese patients (24,6%) (mean BMI 34,80) (SD 5,320) had a mean FACIT-F score 27,96 (SD 7,808), a mean PDQ score 28,34 (SD 4,136), a mean PHQ-9 score 21,43 (SD 2,953) and a mean PSQI score 15,76 (SD 4,150). For each of the FM symptoms investigated the results were statistically significant (p value < 0.0001) between the category of obese and both normal weight and overweight patients, but not statistically significant (p value > 0,05) between the category of normal weight and overweight patients.

Conclusion Our study suggests that obesity is a risk factor for Fibromyalgia severity. Obese patients had higher FACIT-F, PDQ, PHQ-9, PSQI scores than normal weight patients. Therefore, according to these findings, a Fibromyalgia treatment program should include weight loss strategies. Anyway further studies are needed to investigate the association between BMI and Fibromyalgia.

References [1 F. Atzeni et al. The association between body mass index and fibromyalgia severity: data from a cross-sectional survey of 2339 patients. Rheumatology Advances in Practice 2021; 00:1-9.

[2]M. D’Onghia et al. Fibromyalgia and obesity: A comprehensive systematic review and meta-analysis. Seminars in Arthritis and Rheumatism 51 (2021) 409-424.

[3]Jun Hozumi et al. Relationship between Neuropathic Pain and Obesity. Pain Research and Management. Volume 2016, Article ID 2487924, 6 pages.

Acknowledgements: NIL.

Disclosure of Interests None Declared.