Date of Award

Summer 2018

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Physical Therapy

First Advisor

Papanek, Paula E.

Second Advisor

Gottschall, Jerome L.

Third Advisor

Blank, Robert D.

Abstract

Exposure to citrate anticoagulant during apheresis blood donation induces significant decreases in serum ionized calcium with subsequent perturbations to parathyroid hormone, vitamin D, and markers of bone remodeling. Cross-sectional studies of bone mineral density (BMD) among apheresis donors exhibit conflicting results. Resolving the potential impact of the highest apheresis donation frequency represents a significant knowledge gap in ensuring adequate protections for volunteer apheresis blood donors. ALTRUYST (NCT02655055) was a randomized, longitudinal, controlled clinical trial designed to determine if repeated exposure to citrate through apheresis donation reduces BMD. Male donors, 18-65 years of age with no more than five previous apheresis donations and no diseases of bone or mineral metabolism, agreed to make ≥20 apheresis donations in the subsequent one year period. Dual-energy x-ray absorptiometry was performed at baseline and again after one year of participation. Paired t-test was used to assess change in mean BMD. Donors in the apheresis arm (n=26) made a median of 20 donations (range 4–22 donations) during the one-year study period with a mean donation interval of 17.8 days. Controls (n=15) made zero apheresis donations and a median of two whole-blood donations (range 0-6). Mean lumbar spine BMD at the end of the study period did not differ significantly from that at the beginning among donors in the control arm (mean change=-0.002 g/cm2, 95% CI [-0.020, 0.016], p=0.78), nor did it change significantly among donors in the apheresis arm (mean change=0.007 g/cm2, CI [-0.005, 0.018], p=0.24). Change in mean BMD at the total hip was not statistically significant for control donors (mean change=0.002 g/cm2, CI [-0.006, 0.009], p=0.63) or apheresis donors (-0.004 g/cm2, CI [-0.10, 0.002], p=0.16). Tests for differences in proportions of donors with change in BMD exceeding the least significant change (LSC) at the lumbar spine (0.00743 ±0.02058g/cm2) between the apheresis and control arms in either a positive [apheresis 13 (50%), control 5 (33%), p=0.84] or negative direction [apheresis 8 (31%), control 6 (40%)] were statistically non-significant (p=0.87). Proportional increases [apheresis 6 (23%), control 6 (40%), p=0.25] and decreases [apheresis 11 (42%), control 3 (20%)] were not significantly different (p=0.15) at the total hip (LSC=0.00671±0.01859g/cm2).

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