SUN-794 - Changes in Skeletal Health Following Total Parenteral Nutrition and Intestinal Transplantation: A Longitudinal DXA-Based Analysis

Introduction: Patients with chronic intestinal failure are at high risk for metabolic bone disease due to malabsorption, prolonged dependence on total parenteral nutrition (TPN), and exposure to immunosuppressive therapies. However, the impact of TPN initiation, intestinal transplantation, and post-transplant TPN discontinuation on skeletal health remains poorly characterized.

Methods: We conducted a retrospective longitudinal analysis of adults with intestinal failure who underwent serial dual-energy X-ray absorptiometry (DXA) assessments. Two cohorts were evaluated: (1) patients initiating TPN with available pre- and post-TPN DXA scans, and (2) patients undergoing intestinal transplant surgery with pre- and post-operative DXA measurements. In the surgical cohort, changes in bone density were compared between patients who discontinued TPN post-operatively and those who continued TPN, with a secondary analysis examining the association between timing of TPN discontinuation and skeletal outcomes. The primary endpoint was the change in the lowest DXA Z-score; the change in the lowest DXA T-score was a prespecified key secondary endpoint. Multivariable linear regression models adjusted for baseline bone density were used.

Results: Among 98 surgical patients with evaluable lowest Z-scores, those who discontinued TPN after transplant experienced a significantly greater decline in skeletal health compared with those who continued TPN (mean change −0.48 vs −0.13; between-group difference −0.35, p = 0.023). A similar pattern was observed for the lowest T-scores (between-group difference −0.54, p = 0.025). Site-specific analyses demonstrated consistent declines at the lumbar spine and hip in the TPN-discontinued group. Among patients who discontinued TPN, later discontinuation trended toward greater bone loss, though this association did not reach statistical significance. In the TPN initiation cohort (n ≤ 10), pre–post analyses revealed heterogeneous changes in DXA measures, characterized by small mean declines and wide confidence intervals, likely due to the limited sample size.

Conclusions: Skeletal changes following TPN initiation were limited, while discontinuation of TPN following intestinal transplantation was associated with declines in bone density compared with continued TPN. These findings suggest that nutritional transitions may coincide with periods of increased skeletal vulnerability in patients with intestinal failure, supporting the importance of ongoing bone health monitoring and individualized management strategies in this population.

*Unless otherwise noted, all abstracts presented at ENDO must not be released to the press or the public until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.*