Serum myostatin is associated with central-to-peripheral arterial stiffness gradient in healthy adolescents. The MACISTE Study.

BACKGROUND: myostatin is a protein compound structurally related to the TGF-beta protein, which plays a pivotal role in regulating muscle growth and extracellular matrix production. exerts both profibrotic and antihypertrophic effects on vascular smooth muscle cells. Aim of the study was to explore the potential association between serum myostatin levels (sMSTN) and carotid-femoral pulse-wave velocity (cf-PWV), carotid-radial pulse wave velocity (cr-PWV), and their ratio (PWVr), in a cohort of healthy adolescents. METHODS: a cohort of 128 healthy subjects (mean age 17±2 years, 59% male) was randomly selected from participants to the MACISTE (Metabolic And Cardiovascular Investigation at School, TErni) study. sMSTN was assessed utilizing an enzyme-linked immunosorbent assay. PWVs were measured in the supine position using high-fidelity applanation tonometry. RESULTS: The mean cf-PWV was 5.1±0.9 m/s, cr-PWV was 6.9±0.9 m/s, PWVr was 0.75±0.12. PWVr exhibited a linear increase across increasing quartiles of sMSTN (0.71±0.1, 0.74±0.1, 0.7±0.1, 0.77±0.1, p for trend=0.03), whereas the association between sMSTN and each single component of PWVr (cf-PWV, cr-PWV) did not attain statistical significance. Quartiles of sMSTN displayed a positive trend with serum HDL-cholesterol (p=0.01) and a negative one with LDL-cholesterol (p=0.01). In a multivariate linear model, the association between PWVr and sMSTN was independent from SBP values, age, sex, heart rate, BMI, HDL-cholesterol and HOMA Index. CONCLUSIONS: In healthy adolescents, sMSTN showed independent associations with PWVr, a measure of central-to-peripheral arterial stiffness gradient. sMSTN may exert differential effects on the structural and functional properties of the arterial wall.

Myokines and Osteokines in the Pathogenesis of Muscle and Bone Diseases.

PURPOSE OF REVIEW: In this review we aim to summarize the latest findings on the network of molecules produced by muscle and bone under physiological and pathological conditions. RECENT FINDINGS: The concomitant onset of osteoporosis and sarcopenia is currently one of the main threats that can increase the risk of falling fractures during aging, generating high health care costs due to hospitalization for bone fracture surgery. With the growing emergence of developing innovative therapies to treat these two age-related conditions that often have common onset, a broader understanding of molecular messengers regulating the communication between muscle and bone tissue became imperative. Recently it has been highlighted that two muscle-derived signals, such as the myokines Irisin and L-BAIBA, positively affect bone tissue. In parallel, there are signals derived from bone that affect either positively the skeletal muscle, such as osteocalcin, or negatively, such as RANKL.

Irisin levels correlate with bone mineral density in soccer players.

Irisin, a novel myokine produced in response to physical exercise by skeletal muscle, displays anabolic effect on bone and can improve the bone-loss-induced osteoporosis in hind limb suspended mice. It is well known that muscles positively impact the skeleton and in different sports, including soccer, total body bone mineral density (TB-BMD) is elevated. Therefore, we have investigated the correlation between irisin serum levels and total and bone sub-regional BMD in soccer players never studied before. In this study, Caucasian football players of Bari team have been enrolled. Their sera were collected to measure by ELISA kit irisin levels and by dual-energy X-ray absorptiometry (DEXA) analysis measurements of BMD (g • cm−2) in the whole body and different bone sub-regions (head, arms, legs, ribs, dorsal vertebrae, lumbar vertebrae, pelvis) were performed. The BMC (g) was measured in the whole body. By means of Pearson's (R) and Cohen's (d) coefficient we investigated the linear association between the irisin serum levels and BMD. In soccer players, we have found a positive correlation between irisin and TB-BMD as demonstrated by the values of Pearson and Cohen's (d) coefficient. Furthermore, linear association was detected between irisin and BMD of different bone-site such as right arm, lumbar vertebrae and head. A positive trend was also observed analyzing circulating levels of irisin and bone mineral content as well as total Z-score. In conclusion, we have demonstrated the correlation between irisin and total or bone sub-regional BMD in soccer players for the first time, an additional systemic effect of the "sport-hormone" defined myokine.