AbstractBackgroundPersons with HIV may experience greater mobility limitations than uninfected populations. Accurate tools are needed to identify persons at greatest risk of decline. We evaluated the performance of novel muscle weakness metrics (grip, grip/body mass index [BMI], grip/weight, grip/total body fat, grip/arm lean mass) and association with slowness and falls in older persons with or at risk for HIV infection as part of the work of the Sarcopenia Definitions and Outcomes Consortium (SDOC).MethodsWe assessed the prevalence of sarcopenia among 398 men (200 HIV+, 198 HIV−) from the Multicenter AIDS Cohort Study and 247 women (162 HIV+, 85 HIV−) from the Women’s Interagency HIV Study using previously validated muscle weakness metrics discriminative of slowness. Sensitivity and specificity were used to compare new muscle weakness and slowness criteria to previously proposed sarcopenia definitions.ResultsThe prevalence of muscle weakness ranged from 16% to 66% among men and 0% to 47% among women. Grip/BMI was associated with slowness among men with HIV only. Grip/BMI had low sensitivity (25%–30%) with moderate to high specificity (68%–89%) for discriminating of slowness; all proposed metrics had poor performance in the discrimination of slowness (area under the curve [AUC] < 0.62) or fall status (AUC < 0.56). The combination of muscle weakness and slowness was not significantly associated with falls (p ≥ .36), with a low sensitivity in identifying those sustaining one or more falls (sensitivity ≤ 16%).DiscussionClinical utility of new sarcopenia metrics for identification of slowness or falls in men and women with or at risk for HIV is limited, given their low sensitivity.