Sarcopenia and Osteopenia in the Multivisceral Transplant Patient

Abstract

Introduction: Sarcopenia is becoming an increasingly recognised condition. Sarcopenia is seen as part of the normal ageing process but has also been described as a consequence of chronic disease[1][2]. The purpose of this study was to determine if there was a measurable difference in muscle bulk of multivisceral transplant (MVT) patients over a 1 year follow up compared to baseline pre-operative imaging using CT scans. CT has also been validated for determining bone mineral density. We have observed several osteopenic fractures in young patients following MVT. Bone mineral density data was also to be collected from the CT scans of these patients to determine if there was a post-operative pattern. Methods: This was a retrospective study of 55 post-operative multivisceral transplant patients. Their muscle bulk was measured on CT scans performed pre-operatively, and compared with muscle bulk on scans at approximately 3, 6 and 12 months post-operatively. Muscle bulk was measured as total muscle area at the level of the L3 vertebral body pedicles. Bone density was also determined on the same set of CT scans by measuring the Hounsfield Units of the L2 vertebral body. Results: 55 MVT patients were included in the study, 41 patients were followed-up for the total 12 month period. Mean pre-operative muscle bulk was measured at 116.7 cm2 (95% CI 110.0 – 123.4 cm2). At 3 months post-operative (mean 73.0 days, 95% CI 63.9-82.0 days), mean muscle bulk reduced to 89.8% of baseline (p<0.0001) with a mean of 103.2 cm2 (95% CI 96.7 to 109.8 cm2). Average muscle bulk relative to baseline at 6 months (mean 200 days) was 95.0% (p=0.1153) and at 12 months (mean 426 days) was 96.8% (p=0.3045).FIGURE 1: Graph demonstrating trend in muscle bulk relative to baseline following MVT.FIGURE 1: Graph demonstrating trend in bone density relative to baseline following MVT.For the same date ranges, mean bone density dropped at 3 months to 84.1% of baseline (p>0.0001) dropping further to 78.6% of baseline at 6 months (p>0.0001) and recovering to 82.7% of baseline (p>0.0001) by 12 months. Conclusion: A significant loss in muscle bulk was observed in our post-operative MVT patients although this mass was recovered by 6 months post-surgery. A similar loss in bone mineral density was also observed post-operatively however the density remained below baseline levels at 12 months post-transplantation. This observation is important as dietetics and bone protection could be further optimized to prevent complications such as pathological fractures.