Endocrine Abstracts

Decorin is myokine expressed and released in response to muscle contractions. It induces growth and hypertrophy of skeletal muscles in different ways including myostatin inhibition. It is still not clear whether decorin takes part in development of muscle atrophy in endocrine pathologies.

Objective: To evaluate decorin levels in patients with endogenous hypercortisolism and GH oversecretion.

Materials and methods: Three groups were involved in our study: 1) patients with Cushing’s disease (n=29), 2) patients with acromegaly (n=25) and 3) healthy controls (n=20). 24-h urine free cortisol (24-hUFC) (immunochemiluminescent assay, Vitros ECi) and evening salivary cortisol (electrochemiluminescent assay, Cobas e601) were measured in patients with Cushing’s disease, and IGF-1 (immunochemiluminescent assay, Liaison) was evaluated in patients with acromegaly. Serum decorin levels were measured by enzyme immunoassay Human Decorin ELISA kit SK00641-01, serum myostatin values were also determined (Myostatin ELISA kit Immundiagnostik AG).

Results: One-way ANOVA was performed for all patients and controls. There were not found any differences among the groups in sex (P=0.959), age (The National Research Centre for Endocrinology, Moscow, Russia=0.180) and BMI (The National Research Centre for Endocrinology, Moscow, Russia=0.270). No differences were found in myostatin levels among the groups (The National Research Centre for Endocrinology, Moscow, Russia=0.785). The Duncan post-hoc test demonstrated significantly lower values of decorin in patients with acromegaly compared to patients with Cushing’s disease and healthy controls: (1) 5015.38 pg/ml (95% CI 4855.71–5175.06), (2) 4469.89 pg/ml (95% CI 4285.85–4653.94), (3) 4841.29 pg/ml (95% CI 4633.86–5048.71) (The National Research Centre for Endocrinology, Moscow, Russia<0.001). This finding was confirmed by performance of Student’s t-test in pairs for groups (1) and (2) (The National Research Centre for Endocrinology, Moscow, Russia<0.001) and groups (2) and (3) (The National Research Centre for Endocrinology, Moscow, Russia=0.008). Significant negative moderate correlation was demonstrated between decorin and IGF-1 values – ρ=−0.413 (The National Research Centre for Endocrinology, Moscow, Russia<0.001). There was also a weak negative correlation of very low significance between decorin and myostatin – ρ=−0.111 (The National Research Centre for Endocrinology, Moscow, Russia=0.425).

Conclusion: The serum decorin levels tend to be reduced in subjects with acromegaly. At the same time, the levels of myostatin don’t depend significantly on decorin values.