Mtor inhibitor therapy for tuberous sclerosis complex: Longitudinal study of muscle mass determined by abdominal cross-sectional imaging with ct and mri

Abstract

Purpose: To determine the effect of chronic mammalian target of rapamycin (mTOR) inhibition on skeletal muscle mass in patients with tuberous sclerosis complex (TSC). Materials and Methods: In this retrospective study, patients with TSC who were taking mTOR inhibitors and who underwent at least two abdominal CT or MRI examinations between 2005 and 2017 were included (n = 24; 14 males; mean age, 14.5 years 6 7.8 [standard deviation] at first examination). One reviewer drew regions of interest around psoas muscles at L3 to measure cross-sectional area. Multiple linear mixed-effect modeling was performed to evaluate the association between muscle mass and the covariates over time. Results: The 24 patients underwent a total of 129 abdominal CT or MRI examinations. Median duration of mTOR inhibition at last examination was 106 months (range, 1310–3717 days). There was no significant association between the duration of mTOR inhibitor therapy and psoas muscle area on multiple linear mixed-effect modeling (P = .055); however, patient height and height squared were significant predictors of psoas area (P = .014 and P, .0001, respectively). Conclusion: Duration of mTOR inhibition in TSC was not significantly associated with a decrease in psoas muscle area, suggesting that chronic mTOR inhibition is not associated with sarcopenia.