Serum Myostatin and Irisin Levels in Postmenopausal Women: Association With Bone Mineral Density and Muscle Strength

This cross-sectional observational study aims to evaluate the relationship between serum myostatin and irisin levels and bone mineral density and muscle strength in postmenopausal women. Postmenopausal women aged between 50 and 65 years who meet the inclusion criteria will be enrolled in the study. Bone mineral density will be assessed using dual-energy X-ray absorptiometry (DEXA), and participants will be classified into three groups as normal, osteopenic, or osteoporotic according to T-scores.

Serum myostatin and irisin levels will be measured from venous blood samples collected after overnight fasting. Muscle strength will be evaluated using handgrip strength, and functional performance will be assessed with the five times sit-to-stand test. Demographic and clinical characteristics of the participants will also be recorded.

The relationships between serum myostatin and irisin levels and bone mineral density and muscle strength parameters will be analyzed using appropriate statistical methods.

Inclusion criteria

• Postmenopausal women aged between 50 and 65 years Availability of bone mineral density measurement by dual-energy X-ray absorptiometry (DEXA) Willingness to participate in the study

Exclusion criteria

• Presence of malignancy Chronic kidney disease Chronic liver disease Neuromuscular disorders Recent major surgery or trauma Use of medications affecting bone or muscle metabolism