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Metabolic Disruption in Osteoporotic Sheep: Evaluating Vitamin D Deficiency and Cortisone Effects via Biochemical
Gero Knapp1,2, Judith Langenstein3, Natali Bauer3
1Experimental Trauma Surgery, Faculty of Medicine, Justus-Liebig-University of Giessen, Aulweg 128, 35392 Giessen, Germany.
Background/Objectives:
We evaluated serum and urinary biomarkers of bone and energy metabolism in an ovine osteoporosis model (Control, OVX, OVXD, OVXDS) at 0/3/8 months (M).
Methods:
Morning sampling; DXA (ROI 'abdominal width') and linear mixed models for repeated measures.
Results:
Only OVXDS showed severe DXA loss (Z-scores -3.29 at 3 M; -4.86 at 8 M), with ≈20% and ≈30% BMD reductions at 3 M and 8 M versus controls. OVX and OVXD remained within age-expected Z-score ranges at 8 M. At 3 M, OVXDS had hypocalcemia, markedly elevated UFEP, near-zero 25-OH-vitamin-D, and suppressed osteocalcin/NTX (depressed turnover). By 8 M, osteocalcin rose in OVXDS while NTX stayed low, consistent with altered coupling under chronic glucocorticoids and vitamin D deficiency. OVXD showed milder, later changes. Fructosamine and insulin were transiently higher in OVXDS at 3 M; IGF-1 was stable across groups/time.
Conclusions:
Combined ovariectomy, calcium/vitamin-D-deficient diet, and glucocorticoids produce the clearest biomarker signature and DXA loss. Assay cross-reactivity limited PTH/DKK-1/cathepsin-K measurement in sheep; we summarize DXA outcomes and expand assay limitations and future validation plans.
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