Effect of Antiresorptive Therapy on Urinary Hydroxyproline in Postmenopausal Osteoporosis

Abstract

Osteoporosis becomes a serious health threat for older postmenopausal women by predisposing them to an increased risk of fracture. Osteoporosis and associated fractures are an important cause of morbidity and mortality. Special attention is being paid to early detection, management, and treatment of postmenopausal osteoporosis in women. Biochemical markers can enable dynamic and rapid measurement of total body skeletal metabolism and will be clinically useful in the management of postmenopausal osteoporosis women (PMO) and also for assessing the effects of antiresorptive therapy. With this view, we planned to assess osteoclastic activity by determining urinary hydroxyproline in osteoporotic women. The aim of this study is to measure urinary hydroxyproline (expressed as mg of hydroxyproline/g of creatinine) and serum ascorbic acid in postmenopausal women with osteoporosis and without osteoporosis. These biochemical parameters were determined 3 months post antiresorptive therapy (alendronate ? calcium ? vitamin D) in postmenopausal osteoporosis patients. 60 postmenopausal women with osteoporosis in the age group 45-60 years and 60 healthy postmenopausal women (normal bone mineral density) in the same age group were included in the study. Urinary hydroxyproline levels were significantly increased (P \ 0.001) in PMO at baseline level as compared to control group. These levels were decreased significantly (P \ 0.001) post therapy in PMO patients. Serum vitamin C levels were significantly decreased (P \ 0.001) in PMO patients at baseline level as compared to controls. No significant change occurred of serum vitamin C level post therapy. Raised excretion of hydroxyproline at the baseline level might be due to increased degradation of collagen type I from the bone matrix in osteoporosis. Breakdown of collagen seems to be lowered as reflected by lowering of hydroxyproline excretion post antiresorptive therapy. Alteration in the concentration of this marker can be very well utilized to monitor the effectiveness of therapy. Thus simple, direct urinary assay to measure bone resorption is very useful in monitoring the therapy in PMO and may become an integral part of the management of osteoporosis.

Biochemical markers of bone collagen type I metabolism

“…Approximately 10% of released HyP circulates in blood in the protein-bound form. These proteins are filtered and excreted into the urine without metabolic alterations [32,33]. It is considered that collagen is one source of HyP in the body.…”

Diagnostic and prognostic serum marker of cholangiocarcinoma (Review)

“…HYP is an unique amino acid for maintaining cell structure and function, and is a major component of collagen ( 62 ). Excessive acids, MMPs and cathepsin K, could degrade collagen I into HYP ( 63 ). Prakobwong et al ( 35 ) found that the plasma levels of HYP and collagen I were significantly higher in opisthorchiasis patients compared with healthy individuals.…”

Role of Vitamin D<sub>3</sub> on Alkaline Phosphatase, Collagen, and Bone Mineralization: Impact of Biofield Energy Healing Treatment

“…Most of postmenopausal women are high risk for developing this disease. After menopause there was a massive reduction of bone mass that leads to an imbalance of bone resorption and formation [53]. There are numerous factors for the etiology of postmenopausal osteoporosis such as aging, genetic, environmental, hormonal, nutritional, and life style factors [54].…”