Osteoporosis in Liver Transplant Recipients: Defining Incidence and Risk Factors

Introduction: Osteoporosis is common disorder among patients with liver transplantation (LT). However, specific risk factors for bone disease in this population have not been fully elucidated. In general population, research has linked hypertension to osteoporosis, but data linking hypertension and osteoporosis in LT recipients is scarce. Studies have shown that in kidney transplant recipients, high levels of Tacrolimus (TAC) is associated with risk of bone loss, but data on association between use of TAC and bone disease in LT recipients is scarce. We aimed to define the incidence and risk factors associated with bone disease, among our LT recipients. Methods: We conducted a retrospective review of LT recipients from our prospective database with the ICD-9 code V42.7 for “liver replaced by transplant”. The study population included patients who had received LT at our institution between 2010 and 2013. We recorded recipients' DEXA scan findings, age, sex, height, weight, previous medical conditions, drug use, alcohol consumption, and medications. In addition, vitamin D levels, CBC, comprehensive metabolic panel, and lipid panel were recorded before and after LT and at last follow up. All data was recorded in Microsoft Excel and analyzed using mean and SD. Results: Of the 46 recipients identified, 24 had DEXA scans; sixteen (67%) had osteoporosis and 29% had osteopenia, only one had a normal study. The average age at diagnosis was 58 ± 9 years with a male to female ratio of 11:13. The average BMI was 28.0 ± 5.5 kg/m2. Hepatitis C was the most common etiology for transplant (78%). Eighteen (78%) had hypertension and 17 (74%) were diabetic. Seventeen patients (71%) had a history of tobacco use. All recipients (100%) had at least one of these three afore mentioned risk factors. The median vitamin D level was 25 ng/mL and 29 ng/mL in recipients with osteoporosis and osteopenia respectively (P=0.41). The mean corrected calcium level was 9.5 ± 0.79 mg/dL and 9.2 ± 0.75 mg/dL. Sixteen recipients (70%) were on Tacrolimus, which was the most common medication in this population. Conclusion: We had a high incidence of osteoporosis/osteopenia (96%) in our cohort of LT recipients. Bone disease is significant comorbidity in LT recipients. All recipients had either hypertension, diabetes, or a history of tobacco use, and 70% were on Tacrolimus. Prospective studies are required to better define the relation between these risk factors and bone disease in this unique population.