Abstract
BACKGROUND: Sarcopenia, the age-related loss of muscle mass and strength, is aggravated by cardiometabolic and psychosocial burden. Life's Essential 8 (LE8) and its mental-health extension Life's Crucial 9 (LC9) quantify cardio-psycho-metabolic risk, yet their relationship with sarcopenia remains untested. METHODS: Multicenter case-control study of 1,316 consecutive inpatients (≥65 years) enrolled 2019-2025 at two tertiary hospitals in Nanyang, China (Nanyang Central Hospital, n = 740; Nanyang Second People's Hospital, n = 576). Sarcopenia was adjudicated by AWGS-2019. LE8 and LC9 were derived from admission nicotine, diet, sleep, physical activity, BMI, blood pressure, glucose, non-HDL-C, and PHQ-9. Multivariable logistic regression, ROC, and re-classification analyses were performed, adjusted for age, sex, BMI, hemoglobin, albumin, smoking, and comorbidity. RESULTS: Overall sarcopenia prevalence 11.81-14.05%. Mean LC9 was lower in sarcopenic versus non-sarcopenic participants. ROC curves showed LC9 discriminated sarcopenia better than LE8. Across low, moderate, and high categories, sarcopenia prevalence descended steeply with LC9 and modestly with LE8. Multivariable analysis confirmed both scores as independent protectors. CONCLUSION: LC9, a freely calculable metric integrating mental health with cardio-metabolic health, is strongly and independently associated with sarcopenia in hospitalized older adults and outperforms LE8. Routine LC9 assessment at admission may enable early identification and multimodal intervention to prevent muscle loss.