Can EWGSOP2 and SDOC Definitions of Sarcopenia Identify Functional Muscle Quality?

OBJECTIVES: To compare the European Working Group on Sarcopenia in Older People (EWGSOP2) and the Sarcopenia Definition and Outcomes Consortium (SDOC) in identifying muscle quality indexes (MQI) and lower limb muscle performance in older women aged ≥ 65. METHODS: Participants meeting EWGSOP2 and SDOC criteria were classified into the sarcopenia group (GS); others were placed in the non-sarcopenia group (GNS). Using an isokinetic dynamometer, we assessed peak torque (PT), maximal work (MW), and power (POW) of lower limbs. MQI was calculated as the ratio of muscle performance to appendicular lean mass, adjusted for body mass index (BMI) and lean tissue mass of the right lower limb (LTM). RESULTS: We included 96 older women. In both SDOC (n=37) and EWGSOP2 (n=48) sarcopenia groups, muscle performance and BMI-adjusted MQI were significantly lower. Sarcopenia (SDOC) was significantly associated with all lower limb muscle performance and MQI variables [adjusted model by age and race: MQI(POW/LTM) OR = 0.67 (95% CI 0.52; 0.85); MQI(PT/LTM) OR = 0.76 (95% CI 0.64; 0.89)]. CONCLUSIONS: Older women diagnosed with sarcopenia by EWGSOP2 and SDOC criteria showed significant declines in muscle function and quality. The SDOC definition discriminated muscle contraction quality components in older individuals with and without sarcopenia.