TY - JOUR
T1 - Impact of Conventional Medical Therapy on Bone Mineral Density and Bone Turnover in Adult Patients with X-Linked Hypophosphatemia
T2 - A 6-Year Prospective Cohort Study
AU - Shanbhogue, Vikram Vinod
AU - Hansen, Stinus
AU - Jørgensen, Niklas Rye
AU - Beck-Nielsen, Signe Sparre
PY - 2018/3/1
Y1 - 2018/3/1
N2 - X-linked hypophosphatemia (XLH) is a rare, inheritable disorder manifesting as rickets in children and osteomalacia in adults. While conventional medical treatment with oral phosphate and alfacalcidol is recommended in childhood, it is undecided whether adults should continue therapy. The aim of this 6-year prospective study was to determine the impact of conventional medical treatment on areal bone mineral density (aBMD), bone turnover markers (BTMs) and measures of calcium homeostasis in 27 adult patients with XLH, 11 of whom received medical treatment. Lumbar spine and total hip aBMD, as assessed by DXA, and biochemical measures of calcium, phosphate, PTH, 1,25 dihydroxyvitamin D2+3 (1,25(OH)2D), fibroblast growth factor 23 (FGF23), P1NP and CTX were measured at baseline and at follow-up. The renal tubular reabsorption of PO4 (TmPO4/GFR) was calculated at both time points. Multilevel mixed-effects linear regression models were used for analyses. During the study period, spine and hip aBMD did not change significantly between treated and non-treated XLH patients. There was a trend towards a decrease in calcium, phosphate and TmPO4/GFR in the treatment group (p = 0.057, p = 0.080 and p = 0.063, respectively), whereas PTH, FGF23, 1,25(OH)2D and P1NP did not change significantly in either groups. However, CTX increased significantly in the treated compared to non-treated group (p = 0.044). Continuing conventional medical therapy in adulthood, although associated with increased bone resorption, does not promote or prevent loss of bone mass as evidenced from the stable aBMD of the hip and spine in XLH patients.
AB - X-linked hypophosphatemia (XLH) is a rare, inheritable disorder manifesting as rickets in children and osteomalacia in adults. While conventional medical treatment with oral phosphate and alfacalcidol is recommended in childhood, it is undecided whether adults should continue therapy. The aim of this 6-year prospective study was to determine the impact of conventional medical treatment on areal bone mineral density (aBMD), bone turnover markers (BTMs) and measures of calcium homeostasis in 27 adult patients with XLH, 11 of whom received medical treatment. Lumbar spine and total hip aBMD, as assessed by DXA, and biochemical measures of calcium, phosphate, PTH, 1,25 dihydroxyvitamin D2+3 (1,25(OH)2D), fibroblast growth factor 23 (FGF23), P1NP and CTX were measured at baseline and at follow-up. The renal tubular reabsorption of PO4 (TmPO4/GFR) was calculated at both time points. Multilevel mixed-effects linear regression models were used for analyses. During the study period, spine and hip aBMD did not change significantly between treated and non-treated XLH patients. There was a trend towards a decrease in calcium, phosphate and TmPO4/GFR in the treatment group (p = 0.057, p = 0.080 and p = 0.063, respectively), whereas PTH, FGF23, 1,25(OH)2D and P1NP did not change significantly in either groups. However, CTX increased significantly in the treated compared to non-treated group (p = 0.044). Continuing conventional medical therapy in adulthood, although associated with increased bone resorption, does not promote or prevent loss of bone mass as evidenced from the stable aBMD of the hip and spine in XLH patients.
KW - Adolescent
KW - Adult
KW - Aged
KW - Bone Density/drug effects
KW - Bone Density Conservation Agents/therapeutic use
KW - Bone Remodeling/drug effects
KW - Familial Hypophosphatemic Rickets/drug therapy
KW - Female
KW - Fibroblast Growth Factors/metabolism
KW - Humans
KW - Lumbar Vertebrae/drug effects
KW - Male
KW - Middle Aged
KW - Prospective Studies
KW - Young Adult
U2 - 10.1007/s00223-017-0363-3
DO - 10.1007/s00223-017-0363-3
M3 - Journal article
C2 - 29143140
SN - 0171-967X
VL - 102
SP - 321
EP - 328
JO - Calcified Tissue International
JF - Calcified Tissue International
IS - 3
ER -