THU0610-HPR PREDICTION EQUATION FOR MUSCLE MASS OVERESTIMATES MUSCLE MASS IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background: Factors associated with handgrip strength (HGs), in female with fibromyalgia (FM), use of force-time (FeT) curve to assess peak force, area under the curve (AUC), and variability of the time to reach maximum plateau of the curves (Fig.1) (1) to identify the impact of FM patients versus healthy controls have not been extensively studied. Objectives: The aim of the study was to compare the HGs of FM with healthy subjects and to evaluate the relationship between curve characteristics and FM disease severity (2,3). Methods: One hundred and ten women (mean age 53.8±12.4 years; range 18 to 80) were included and compared with 111, age and BMI matched, female healthy controls. HGs was measured with an electronic device, while demographic and clinical characteristics of the subjects were obtained by the Revised version of the Fibromyalgia impact questionnaire (FIQR) and Fibromyalgia Activity Score (FAS). The patient opinion of their symptoms state (PASS) was evaluated as external criterion. The HGs threshold that best discriminates between the presence and absence of FM, as well as between moderate and severe FM, was determined using the receiver operating characteristic (ROC) curves analyses. Multivariate regression procedure was used in order to assess the relative contribution of the covariates on the HGs. Results: HGs-AUC and peak force levels were lower in patients with FM than healthy women (median 342.7 vs 496.5; and in Kg median was 13.9 vs 19.9, respectively; both at significant level of p 0.001). ROC analyses revealed that the HGs peak force threshold that best discriminated between the presence and absence of FM was 14.2 kg (AUC 0.801; p Conclusion: HGs is reduced in woman FM patients and is inversely related to FM severity and symptomatology. The FeT curve gave more information about grip in the FM and could be used as a complementary tool in the assessment and monitoring of FM. Further research on male FM patients is needed to confirm or contrast these findings. References: [1]Dias, J.J., Singh, H.P., Taub, N. & Thompson, J. Grip strength characteristics using force-time curves in rheumatoid hands. J Hand Surg Eur Vol.38, 170-177 (2013). [2]Salaffi, F., Di Carlo, M., Arca, S. & Galeazzi, M. Categorisation of disease severity states in fibromyalgia: a first step to support decision-making in health care policy. Clin Exp Rheumatol. 36, 1074-1081 (2018). [3]Aparicio, V.A., Ortega, F.B., Heredia, J.M., Carbonell-Baeza, A., Sjostrom, M. & Delgado-Fernandez, M. Handgrip strength test as a complementary tool in the assessment of fibromyalgia severity in women. Arch Phys Med Rehabil. 92, 83-98 (2011). Disclosure of Interests: None declared