Prevalence and Blood Biochemical Parameters Associated with Sarcopenia Among Korean Postmenopausal Women Aged 50 Years and Older: A Nationwide Cross-Sectional Study

Background/Objectives: Sarcopenia is a growing health concern from midlife, but evidence on its biochemical correlates among postmenopausal women younger than 65 years remains limited. This study aimed to estimate sarcopenia prevalence and explore associations with blood biochemical parameters among Korean postmenopausal women aged ≥50 years using the Asian Working Group for Sarcopenia (AWGS) 2025 age-specific diagnostic criteria. Methods: We analyzed 2024 Korea National Health and Nutrition Examination Survey data from 1157 postmenopausal women aged ≥50 years with complete muscle and biochemical measurements. The 13 biochemical parameters were glycated hemoglobin, total cholesterol, high-density lipoprotein cholesterol, triglycerides, hemoglobin, creatinine, aspartate aminotransferase, high-sensitivity C-reactive protein, calcium, phosphorus, magnesium, parathyroid hormone, and serum 25-hydroxyvitamin D3. Complex sample logistic regression examined each parameter’s association with sarcopenia, adjusting for age alone or age, body mass index (BMI), and age at menopause. Results: The weighted prevalence of sarcopenia was 10.5% overall and 9.7% among women aged 50–64 years. Triglycerides were not significantly associated with sarcopenia in the age-adjusted model. However, in the model adjusted for age, BMI, and age at menopause, each 10 mg/dL increase in triglyceride levels was associated with approximately 5.1% higher odds of sarcopenia (aOR = 1.051, 95% CI: 1.020–1.072, p < 0.001). Higher hemoglobin levels were associated with lower odds of sarcopenia in the age-adjusted model (aOR = 0.734, 95% CI: 0.599–0.901, p = 0.003). Both associations remained significant after false discovery rate correction. Conclusions: These findings highlight the importance of muscle health before older age in postmenopausal women. Biochemical parameters may have potential relevance to muscle health assessment, but their clinical utility requires further validation.