PTH and endocrine system disorder: No statistically significant differences were observed between the two groups upon comparison of the biochemical parameters (ALB, ALT, AST, ALP, CREA, UREA, UA, FPG, Ca, P, K, Na, TG, TC, LDL, and PTH) in Table 3, indicating that secondary osteoporosis caused by common reasons, such as endocrine diseases and nutritional factors, could be excluded.