Utilizing Generalized Linear Mixed Effects Models for Prediction of Bone Mineral Decrease After Lung Transplant - A Preliminary Study.

Abstract

Recipients of lung transplants are at heightened risk of developing low bone mineral density (BMD). They also have increased risk of developing osteoporosis-related fractures. This rate of BMD decline is not well characterized. The aim of this manuscript is to characterize the rate of BMD decrease after lung transplant. This is a preliminary retrospective cohort study of 200 patients who received lung transplants. Each patient had pre-transplant dual energy X-ray absorptiometry (DXA) and post-transplant DXA scans on the same DXA scanner. The BMD at each lumbar vertebra, total hip, and femoral neck were recorded. Generalized linear mixed effects models with random intercepts and random slopes were used to model the rate of change of BMD after transplant, adjusting for time since transplant, sex, and sex*time interaction. We found that men had higher baseline BMD than women at all sites (P<0.05 for all). The rate of BMD decrease was fastest at the femoral neck (P<0.05). Men lost BMD at a faster rate (-5.23 x10-5 g/cm2/day) than women at the femoral neck (-2.22 x10-5 g/cm2 /day). BMD decreases after lung transplant and occurs faster in men than women.