| Objective To study the effect of a high-fat diet on bone health of mice at different age periods. Methods C57BL/6J male mice were randomly divided into 4 groups: 6-month-old normal diet group, 6-month-old high-fat diet group, 12-month-old normal diet group, and 12-month-old high-fat diet group. After 16 weeks of feeding, the mice were sacrificed. Serum of mice was collected to detect the levels of serum lipids (TC, TG, HDL-C, LDL-C), oxidative stress and inflammation markers (SOD, MDA, IL-6, TNF-α), and bone metabolism marker (PINP, CTX-1). The femurs of mice were collected to analyze the microstructure of the cancellous bone. The bone morphology was studied using micro-CT and HE staining. Results Compared to those in the normal diet group, the body weight and body fat rate of mice increased in high-fat diet group at different months (P<0.05), the levels of TC, TG, and LDL-C in serum also increased (P<0.05), and the highest level was found in 12-month-old high-fat diet group. Compared to those in normal diet group, micro-CT showed that BV/TV and BS/TV were lower in high-fat diet group (P<0.05), and bone microstructure damage was obvious. HE staining showed that bone trabecula decreased in high-fat diet group. The bone mass and bone trabecular number of mice at 12-months-old group were significantly lower than those in 6-months-old group, and the changes were more obviously in 12-month-old high-fat diet group. The levels of IL-6, TNF-α, and MDA increased in high-fat diet group compared to those in normal diet group at different months (P<0.05). The level of CTX-1 in serum increased at 6-month-old high-fat diet group compared to that in normal diet group (P<0.05). Conclusion The high-fat diet and advanced age aggravate oxidative stress and inflammation, and damage the bone health of mice. The adverse effect was more obvious when both acted together. |