People living with HIV (PLWH) face an increased risk of aging-related comorbidities, including sarcopenia.¹ Sarcopenia is defined by loss of muscle mass, strength, and function, with multiple consensus definitions incorporating these components.¹ However, these diagnostic methods require specialized assessments that are often impractical in routine clinical settings.¹ To address this, the 5-item Strength, Ambulation, Rising from a Chair, and History of Falling (SARC-F) questionnaire was developed as a simple screening tool for sarcopenia.¹ While SARC-F has been validated in the general population, its accuracy in PLWH has not been well established.¹ At the 2025 CROI, Dr. Joselito Malca-Hernandez from Yale University presented the first study to validate SARC-F in PLWH, comparing its performance against the European Working Group on Sarcopenia in Older People (EWGSOP 2019) and the Asian Working Group on Sarcopenia (AWGS 2019) definitions.¹

Dr. Malca-Hernandez and his team conducted a cross-sectional study of 210 PLWH (105 women, 105 men) aged ≥45 years across three HIV clinics in Lima, Peru.¹ Patients’ mean ages were 55.2±7.1 and 54.8±7.6, respectively.¹ Patients completed demographic and clinical surveys, the validated Spanish language SARC-F (score range: 0-10, score ≥4 indicating a high likelihood of sarcopenia), the Short Physical Performance Battery, grip strength, and a dual-energy x-ray absorptiometry body composition scan for appendicular skeletal muscle index.¹ Sarcopenia spectrum was classified per EWGSOP 2019 and 2019, and AWGS 2019 definitions.¹ Sex-based differences in the presence of sarcopenia spectrum were analyzed using chi-square or Fisher’s exact tests.¹

The primary endpoint of the study was the validity of SARC-F to identify individuals with sarcopenia, compared to EWGSOP 2019 and AWGS 2019 criteria, assessed with sensitivity, specificity, positive and negative predictive values (PPV/NPV), and area under the receiver operating curve (AUC).¹ 22.7% of participants had a SARC-F score ≥4, with sarcopenia prevalence higher in women than in men across both EWGSOP 2019 and AWGS 2019 criteria.¹ Based on EWGSOP 2019 criteria, sarcopenia spectrum (presarcopenia, sarcopenia and severe sarcopenia) was more prevalent in women compared to men (38.1% vs. 21.9%; p<0.05).¹ A similar trend was observed with AWGS 2019 criteria (46.7% vs. 24.7%; p<0.01), reinforcing the sex-based differences in sarcopenia risk.¹ When evaluating SARC-F (cutoff score ≥4) against these reference standards, specificity was high across definitions (EWGSOP 2019: 80.2-82.7%, AWGS 2019: 80.8%), reflecting a low likelihood of false positives.¹ However, sensitivity was low (EWGSOP 2019: 39.3-39.6%, AWGS 2019: 39.4%), indicating that many true cases of sarcopenia were missed.¹ PPV was low for both definitions (EWGSOP 2019: 23.4%, AWGS 2019: 27.7%), while NPV was higher (EWGSOP 2019: 82.2%, AWGS 2019: 87.7%), suggesting that a negative SARC-F score may reliably exclude sarcopenia.¹ The AUC, on the other hand, was moderate (0.66-0.67), reflecting fair discrimination.¹

In conclusion, SARC-F (cutoff ≥4) demonstrated acceptable specificity but low sensitivity for detecting sarcopenia in PLWH.¹ Its moderate discrimination supports its potential as a screening tool, though alternative cut-points may improve its predictive accuracy.¹ Future studies should explore optimized thresholds and integration of SARC-F into clinical workflows, particularly in resource-limited settings where comprehensive sarcopenia assessments are unfeasible.¹