The Prevalence of Sarcopenia in Patients with newly diagnosed Rheumatoid Arthritis and associated factors
Bernie McGowan1,2, Noreen Harrington1, Mary Jane Reodica1, Sarah McDonald1, Keunjae Ahn3, Miriam O Sullivan1,3, Bryan Whelan1,3, Carmel Silke1,3.
1. The North Western Rheumatology Unit, Our Lady’s Hospital, Manorhamilton, Co Leitrim, 2. The Department of Pharmacology and Therapeutics, Trinity College Dublin 3. The Dept of Medicine, NUIG
The European Working Group on Sarcopenia in Older People (EWGSOP) defines sarcopenia as a progressive and generalised loss of skeletal muscle mass and strength either age or disease activity related or both. Furthermore, sarcopenia has been commonly identified in patients with chronic inflammatory diseases, such as rheumatoid arthritis (RA).
To identify:1) the prevalence of sarcopenia in newly diagnosed Rheumatoid Arthritis (RA) patients attending the NWRU 2) factors associated with sarcopenia. 3) changes in body composition 12 months post initiation of therapy in these patients preprocess
A total of 108 patients (females 57 (53%), males 51 (47%)), newly diagnosed with RA were included in the study. Body Composition including Appendicular Lean Mass and Tissue % Fat were measured using Dual-Energy-X-ray-Absorptiometry (DXA) scan. Disease activity was measured using the CDAI, quality of life using the HAQ scores and muscle strength using the Handgrip Strength. Additional information recorded included numbers of co-morbidities, duration of symptoms and level of exercise. Sarcopenia is quantified as appendicular skeletal mass divided by height squared (ASM/H²) and considered present if the calculated skeletal muscle mass index (SMI) is two standard deviations (SD) below the mean for a population of young adults as based on the Rosetta study2. In total 30 of the patients had a repeat DXA scan carried out approximately 12 months post initial visit. All data was recorded and analysed on SPSS version 23.0. Factors associated and related to sarcopenia were assessed using Independent T tests.
The prevalence of sarcopenic muscle mass was 22.2% (25% in men, 19% in females). The prevalence of sarcopenic muscle mass and sarcopenic muscle strength was 12% (11% in females and 14% in males). While not statistically significant patients with sarcopenic muscle mass tended to be older and had reduced dominant hand grip strength. There was no statistically significant association identified in the HAQ or CDAI scores between the groups or in duration of symptoms. There was an overall 3.5% (+5.87) increase in the SMI/kg2 between the first and second DXA scan with no significant difference between the sarcopenic and non sarcopenic patients (P=.498).
The prevalence of sarcopenia in patients newly diagnosed with RA attending the NWRU was 22.2%. Results of previously published studies suggest that sarcopenia is a reversible cause of disability and may benefit from intervention, especially at the early stage.