1Hepatology Unit, Centre for Digestive Diseases, Blizard Institute, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, UK.
2Department of Hepatology, Barts Health NHS Trust, London, UK.
3Department of Hepatology, Faculty of Medicine, Imperial College London, St Mary's Hospital, Paddington, London, UK.
4Department of Infectious Diseases, Brownlee Centre for Infectious & Communicable Diseases, NHS Greater Glasgow & Clyde, Glasgow, UK.
Tenofovir Disoproxil Fumarate (TDF) is an established nucleotide (NUC) analogue in the treatment of Chronic Hepatitis B (CHB). Bone Mineral Density (BMD) loss has been described in TDF treated Human Immunodeficiency virus (HIV) patients, but limited data exist in CHB. Dual X-ray absorptiometry (DEXA) scanning was used to determine BMD changes in TDF exposed patients; we evaluated the accuracy of the FRAX score as an alternative to DEXA in clinical practice.
170 patients were studied; 122 exposed to TDF, 48 controls. All patients underwent DEXA scan and demographic details were recorded. FRAX scores (pre & post-DEXA) were calculated.
TDF was associated with a lower hip T-score (p=0.02). On univariate and multivariate analysis, advancing age, smoking, lower BMI along with TDF exposure were independent predictors of low BMD. In addition the pre-DEXA FRAX score was an accurate predictor of the post-DEXA FRAX treatment recommendation (100% sensitivity, 83% specificity), AUC 0.93 (95% CI 0.87 to 0.97, p<0.001).
TDF treated CHB patients have reduced BMD, but limited to one anatomical site. Age and advanced liver disease are additional contributing factors, underlining the importance of multifactorial fracture risk assessment. FRAX can accurately identify those at greatest risk of osteoporotic fracture.