Background: Type 2 Diabetes Mellitus (T2DM) in young adults is associated with an increased risk of early sarcopenia due to insulin resistance and inflammation. This insulin resistance and inflammation can be influenced by leptin and adiponectin, which are key adipocytokines produced by adipose cells. However, no studies have examined the relationship between leptin, adiponectin levels, and sarcopenia in T2DM patients under 60 years old. This study aimed to investigate the relationship between leptin, adiponectin levels, and Leptin-to-Adiponectin ratio (LAR) with sarcopenia in non-geriatric T2DM patients. Methods: This cross-sectional study was conducted from January 2021 to April 2022. The subjects consisted of T2DM patients aged 18-59 years at Cipto Mangunkusumo Hospital, Jakarta, Indonesia. Baseline data were sourced from a primary study, while stored serum samples were analyzed for leptin and adiponectin using ELISA. Leptin and adiponectin differences were assessed statistically using the Mann-Whitney U test, and the Kruskal-Wallis test was used for additional analysis. Results: Among 97 subjects, 4 (4.1%) had sarcopenia, while 34 out of 93 non-sarcopenic subjects belonged to the possible sarcopenia category. Bivariate analysis results showed significant differences between leptin levels (p=0.005) and the Leptin-to-Adiponectin Ratio (LAR) (p=0.003) with sarcopenia in non-geriatric T2DM patients. Meanwhile, adiponectin levels (p=0.799) did not show statistical differences. Further analysis was conducted among three groups, namely sarcopenia, possible sarcopenia, and non-sarcopenia. The result showed statistically significant differences in leptin and LAR levels between sarcopenia and possible sarcopenia (leptin p=0.004; LAR p=0.007) as well as sarcopenia and non-sarcopenia (leptin p=0.038; LAR p=0.011). Conclusion: Leptin levels and LAR were associated with sarcopenia in a non-geriatric T2DM population. © 2025, Indonesian Society of Internal Medicine. All rights reserved.