Relation of testosterone level and other factors with bone mineral density in male kidney transplant recipients: a cross-sectional study.

BACKGROUND: Although testosterone has a pivotal role in bone health, its correlation with bone mineral density (BMD) is understudied in kidney transplant recipients who are at high risk of osteoporosis. This study aimed to elucidate if there is any correlation between serum free testosterone and BMD in this population. PATIENTS AND METHODS: Sixty male kidney transplant recipients were enrolled in this cross-sectional study, and they were subjected to history taking, clinical examination, and laboratory investigations (including total and free testosterone). BMD was assessed in three regions (forearm, hip, and lumbar spine) using DEXA scan. RESULTS: The mean age of the included patients was 45.55 ± 13.58 years. Serum total and free testosterone had mean values of 5.17 ± 1.4 ng/ml and 95.46 ± 28.24 pg/ml, respectively, with all levels within the normal range. DEXA scan detected osteoporosis and osteopenia in 9 (15%) and 30 (50%) patients in the lumbar region, 3 (5%) and 36 (60%) in the hip region, as well as 21 (35%) and 33 (55%) in the forearm region, respectively. BMD of the lumbar region had a significant positive correlation with free testosterone, phosphorus, and eGFR, while it had a significant negative correlation with platelets and patient age. BMD of the hip region was positively correlated with serum phosphorus, parathyroid hormone, and duration since the transplant, whereas it was negatively correlated with platelets and total testosterone level. BMD of the forearm had a significant positive correlation with eGFR, whereas it had a significant negative correlation with age and duration since transplantation. In addition, forearm BMD was significantly lower in patients with a radiocephalic AVF. CONCLUSION: Even within the normal range, free testosterone has a significant positive correlation with lumbar spine BMD with no significant association with the forearm or hip BMD.

DObesity: Relationship between vitamin D deficiency, obesity and sclerostin as a novel biomarker of bone metabolism.

AIM: To study the relationship between obesity, insulin resistance, vitamin D deficiency and sclerostin as a bone biomarker. MATERIALS AND METHODS: Cross-section study of 75 subjects grouped into 3 groups; obese (n = 31), overweight (n = 23) and normal (n = 21) subjects. Sclerostin, fasting insulin, fasting plasma glucose and 25(OH)D were measured and anthropometric measures were taken. RESULTS: 25(OH)D was lower in obese subjects than overweight and control groups (mean ±â€¯SD 5.27 ±â€¯5.14 vs. 12.55 ±â€¯6.99 vs.17.65 ±â€¯4.07 ng/L, p < 0.001). Sclerostin was significantly lower in obese subjects versus the control (mean ±â€¯SD 1.02 ±â€¯0.45 vs 1.58 ±â€¯0.83 ng/mL, p = 0.014). CONCLUSION: These results lead us to hypothesize that the relationship between sclerostin and Vitamin D levels has an important role in the link between obesity and bone metabolism. DObesity could be an active focus of research in the coming years.