Urinary hydroxyproline

Urine hydroxyproline can reflect both bone resorption and bone formation. Its excretion is affected by many hormones, such as thyroid hormones, growth hormones, adrenocortical hormones, sex hormones, and so on. Increased urinary hydroxyproline excretion can be seen in children's growing season, bone destructive diseases (such as hyperthyroidism, bone metastatic cancer), poor bone mineralization diseases (such as cartilage disease, rickets, high conversion osteoporosis, Deformity osteitis) and so on. Urinary hydroxyproline has a tendency to decrease with age, but the ratio of urinary hydroxyproline to creatinine increases with age. Hydroxyproline is the main component of collagen in human connective tissue, accounting for about 10% to 13% of collagen. 50% of hydroxyproline in urine comes from bone tissue. Therefore, urinary hydroxyproline excretion can basically reflect changes in bone metabolism, especially with a significant relationship with bone resorption rate.