The correlation between sclerostin and bone mineral density in renal transplant recipients

Sclerostin is an anti-anabolic protein synthesized by osteocytes that may cause osteoporosis by inhibiting bone formation. The aim of our study was to investigate the correlation between sclerostin and bone mineral density (BMD) reduction in renal transplant recipients (RTRs) with more than 1 year after transplantation.

This cross-sectional study was conducted on 80 patients (38 (47.5%) male/42 (52.5%) female) RTRs with a mean age of 44.68±10.39 years. Patients were compared with an age and sex-matched control group of 40 healthy individuals. BMD was measured by dual-energy X-ray absorptiometry. The levels of sclerostin were determined using enzyme-linked immunosorbent assay.

The mean sclerostin was 3.77±0.3pg/mL in patients and 3.81±0.21pg/mL in healthy individuals. The mean T score of femoral trochanter (FT) (FT-T), femoral neck (FN) (FN-T), lumbar vertebrae (L1-4) (L1-4-T) were -0.81±0.86, -1.08±1.09 and -0.8±1.2, respectively. The mean Z score of FT (FT-Z), FN (FN-Z), L1-4 (L1-4-Z) were -0.6±0.73, -0.32±0.9 and -0.54±1.13, respectively. FT-Z and L1-4-Z were lower in patients than healthy subjects (p=0.009, p=0.021 respectively). Serum creatinine (p<0.001), intact parathyroid hormone (p<0.001) were higher and phosphate (p<0.001), was lower in patients than healthy subjects. Patients with a log₁₀ sclerostin of >3.84pg/mL had higher FT-T (p=0.040), FT-Z, FN-T (p=0.018), FN-Z (p=0.006) than those with a log₁₀ sclerostin of ≤3.84pg/mL. There was a significant correlation between log₁₀ sclerostin and FN-T (r=-0.296, p=0.009) and FN-Z (r=-0.269, p=0.019). In linear regression analysis, high sclerostin was found to be correlated with male gender, lower FN-T and lower FN-Z independently of other risk factors.

The levels of sclerostin can predict reduction of proximal femur BMD and development of mineral and bone disorder in RTRs. There was no difference in sclerostin levels between RTRs and healthy individuals.