Influences of teriparatide administration on marrow fat content in postmenopausal osteopenic women using MR spectroscopy

Objective Teriparatide could induce osteoblast differentiation of mesenchymal stem cells while inhibiting adipocyte differentiation. However, there are significant differences between ex vivo and in vivo models. We aimed to evaluate the impact of teriparatide on marrow and abdominal fat accumulation in postmenopausal osteopenic women.Methods Postmenopausal osteopenic women were randomly assigned to receive teriparatide or placebo for 12 months. Subcutaneous (SAT) and visceral adipose tissue (VAT), marrow fat fraction (MFF), bone density (BMD) and bone biomarkers were measured at baseline, 6 and 12 months.Results At 12 months, mean percentage changes in BMD from baseline were 3.51%, 2.21% and 1.80% at lumbar spine, total hip and femoral neck for the teriparatide group, respectively. Relative to baseline conditions, teriparatide reduced MFF (-3.54% at 6 months; -5.87% at 12 months, all p<0.01). A significant difference in MFF, but not BMD, was first detected at 6 months (p=0.012) between groups. MFF was negatively associated with SAT (r=-0.479) and positively associated with VAT (r=0.531) and VAT/SAT (r=0.415, all p<0.05). Teriparatide treatment did not alter abdominal fat composition.Conclusion Teriparatide effectively lowers marrow adiposity but not abdominal fat accumulation in postmenopausal osteopenic women.