Differential effects of teriparatide on regional bone formation using (18)F-fluoride positron emission tomography

TY - JOUR

T1 - Differential effects of teriparatide on regional bone formation using (18)F-fluoride positron emission tomography

AU - Frost, Michelle L

AU - Siddique, Musib

AU - Blake, Glen M

AU - Moore, Amelia E B

AU - Schleyer, Paul J

AU - Dunn, Joel T

AU - Somer, Edward J

AU - Marsden, Paul K

AU - Eastell, Richard

AU - Fogelman, Ignac

N1 - Copyright © 2011 American Society for Bone and Mineral Research.

PY - 2011/5

Y1 - 2011/5

N2 - Teriparatide increases skeletal mass, bone turnover markers, and bone strength, but local effects on bone tissue may vary between skeletal sites. We used positron emission tomography (PET) to study (18)F-fluoride plasma clearance (K(i)) at the spine and standardized uptake values (SUVs) at the spine, pelvis, total hip, and femoral shaft in 18 postmenopausal women with osteoporosis. Subjects underwent a 1-hour dynamic scan of the lumbar spine and a 10-minute static scan of the pelvis and femurs at baseline and after 6 months of treatment with 20 µg/day teriparatide. Blood samples were taken to derive the arterial input function and lumbar spine K(i) values evaluated using a three-compartment model. SUVs were calculated for the spine, pelvis, total hip, and femoral shaft. After 6 months treatment with teriparatide, spine K(i) values increased by 24% (p = .0003), while other model parameters were unchanged except for the fraction of tracer going to bone mineral (k(3)/[k(2) + k(3)]), which increased by 23% (p = .0006). In contrast to K(i) , spine SUVs increased by only 3% (p = .84). The discrepancy between changes in K(i) and SUVs was explained by a 20% decrease in (18)F(-) plasma concentration. SUVs increased by 37% at the femoral shaft (p = .0019), 20% at the total hip (p = .032), and 11% at the pelvis (p = .070). Changes in bone turnover markers and BMD were consistent with previous trials. We conclude that the changes in bone formation rate during teriparatide treatment as measured by (18)F(-) PET differ at different skeletal sites, with larger increases in cortical bone than at trabecular sites.

AB - Teriparatide increases skeletal mass, bone turnover markers, and bone strength, but local effects on bone tissue may vary between skeletal sites. We used positron emission tomography (PET) to study (18)F-fluoride plasma clearance (K(i)) at the spine and standardized uptake values (SUVs) at the spine, pelvis, total hip, and femoral shaft in 18 postmenopausal women with osteoporosis. Subjects underwent a 1-hour dynamic scan of the lumbar spine and a 10-minute static scan of the pelvis and femurs at baseline and after 6 months of treatment with 20 µg/day teriparatide. Blood samples were taken to derive the arterial input function and lumbar spine K(i) values evaluated using a three-compartment model. SUVs were calculated for the spine, pelvis, total hip, and femoral shaft. After 6 months treatment with teriparatide, spine K(i) values increased by 24% (p = .0003), while other model parameters were unchanged except for the fraction of tracer going to bone mineral (k(3)/[k(2) + k(3)]), which increased by 23% (p = .0006). In contrast to K(i) , spine SUVs increased by only 3% (p = .84). The discrepancy between changes in K(i) and SUVs was explained by a 20% decrease in (18)F(-) plasma concentration. SUVs increased by 37% at the femoral shaft (p = .0019), 20% at the total hip (p = .032), and 11% at the pelvis (p = .070). Changes in bone turnover markers and BMD were consistent with previous trials. We conclude that the changes in bone formation rate during teriparatide treatment as measured by (18)F(-) PET differ at different skeletal sites, with larger increases in cortical bone than at trabecular sites.

KW - Bone Remodeling

KW - Bone and Bones

KW - Positron-Emission Tomography

KW - Teriparatide

KW - Humans

KW - Aged

KW - Demography

KW - Fluorine Radioisotopes

KW - Bone Density

KW - Middle Aged

KW - Fluorides

KW - Statistics, Nonparametric

KW - Biological Markers

KW - Female

KW - Osteogenesis

U2 - 10.1002/jbmr.305

DO - 10.1002/jbmr.305

M3 - Article

C2 - 21542003

SN - 1523-4681

VL - 26

SP - 1002

EP - 1011

JO - Journal of Bone and Mineral Research

JF - Journal of Bone and Mineral Research

IS - 5

ER -