Objective To investigate the clinical correlation between plasma resistin levels and sarcopenia in the elderly, and evaluate its preliminary screening value for sarcopenia in the elderly, providing a reference for early identification and intervention of sarcopenia in the elderly. Methods A case-control study design was used. A total of 363 elderly patients who met the inclusion and exclusion criteria in the Department of Geriatrics of the First Hospital of Lanzhou University from December 2021 to December 2023 were enrolled as research subjects. The diagnosis of sarcopenia was based on the 2019 consensus of the Asian Working Group for Sarcopenia. Patients were divided into sarcopenia group and non-sarcopenia group, according to the presence of sarcopenia, and the differences in plasma resistin levels between the two groups were compared. Pearson correlation analysis was conducted to analyze the correlation between plasma resistin levels and sarcopenia indicators, such as grip strength, five-time sit-to-stand test time, gait speed, and appendicular skeletal muscle mass index (ASMI). Logistic regression analysis was used to analyze the independent correlation between plasma resistin levels and sarcopenia in the elderly, and the receiver operating characteristic (ROC) curve was used to evaluate its performance in identifying elderly individuals at high risk for sarcopenia. Results A total of 363 elderly patients were included, including the sarcopenia group (178 cases, including 80 males and 98 females) and the non-sarcopenia group (185 cases, including 98 males and 87 females). The plasma resistin levels in the sarcopenia group were significantly higher than those in the non-sarcopenia group (7.04±1.63 ng/mL vs. 6.11±1.26 ng/mL, P<0.05). Pearson correlation analysis showed that plasma resistin levels in the elderly population were negatively correlated with grip strength, gait speed, and ASMI (P<0.05). Meanwhile, the Mann-Whitney U test showed no difference in plasma resistin levels between elderly males and females (P>0.05), indicating that resistin levels in the elderly were not influenced by gender. In multivariate logistic regression analysis, after adjusting for confounding factors including age, smoking history, alcohol consumption history, and geriatric nutritional risk index (GNRI), red blood cell count, body mass index (BMI), hypertension, triglycerides, and high-density lipoprotein, the results showed that plasma resistin level remained an independent risk factor for sarcopenia in the elderly (OR=1.663, P<0.01). Stratified logistic regression analysis showed that elevated plasma resistin levels were a risk factor for sarcopenia in older adults in both the hypertension subgroup (OR=1.46, P<0.01) and the non-hypertension subgroup (OR=2.66, P<0.01). However, the interaction test indicated that the effect modification of hypertension status on the association between plasma resistin and sarcopenia did not reach statistical significance (P for interaction=0.078). ROC curve analysis showed that the area under the curve for plasma resistin level in the preliminary screening of sarcopenia in the elderly was 0.712 (P=0.027), with an optimal cut-off value of 5.83 ng/mL, corresponding to a sensitivity of 87.1% and a specificity of 48.1%. Conclusions Plasma resistin levels are significantly elevated in elderly patients with sarcopenia and are independently associated with sarcopenia. It may serve as a preliminary screening biomarker for sarcopenia in the elderly. Howe-ver hypertension status did not show a significant effect modification on this association.