Postmenopausal Iron Overload Exacerbated Bone Loss by Promoting the Degradation of Type I Collagen

117 postmenopausal women were divided into Normal, Bone loss (BL), and Osteoporosis group. Compared with Normal group (120.96 ± 43.18 μg/L), the serum ferritin (Fer) in BL (223.37 ± 130.27 μg/L) and Osteoporosis group (307.50 ± 161.48 μg/L) was significantly increased (p < 0.05). Fer level was negatively correlated with BMD (p < 0.01). TRACP levels in Osteoporosis group (4.37 ± 1.69 U/L) were significantly higher than Normal group (4.10 ± 1.60 U/L, p < 0.05). ALP levels in Osteoporosis group (112.06 ± 62.05 U/L) were significantly upregulated compared with Normal group (80.22 ± 14.94 U/L, p < 0.05). β-CTX and PINP were the degradation products of type I collagen. β-CTX levels in Osteoporosis group (667.90 ± 316.55 ng/L) were significantly increased compared with Normal group (406.06 ± 112.12 ng/L, p < 0.05). PINP levels in Osteoporosis group (78.03 ± 37.31 μg/L) were significantly higher than Normal group (37.60 ± 13.17 μg/L, p < 0.01). More importantly, there was a positive correlation between serum Fer and PINP (p < 0.01). Serum Fer showed a positive correlation of serum β-CTX (p < 0.01). The overloaded iron improved the degradation of type I collagen.