Diagnostic and screening utility of biochemical markers for osteoporosis and osteopenia in Saudi women

ABSTRACT

Postmenopausal osteoporosis is a major health problem worldwide and in Saudi Arabia as it leads to bone fragility and increased liability for fragile fractures, particularly in neck of femur and vertebrae. The present study was designed to determine the value of different screening tests to find out the most sensitive serum and urinary markers of osteoporosis among Saudi women and to clarify the relationship between E[2] deficiency and these markers in peri-menopause, early or postmenopausal women without hormonal replacement therapy. This study included 37 Saudi women aged 40 to 60 years. They were categorized into 3 groups according to their bone mineral density [BMD] Group I 15 Normal control [T-score up to -1.5], Group II 12 Osteopenic women [T-score between -1.5 to 2.5]and Group III10 Osteoporotic women [T-score below 2.5]. For all subjects, dual energy X-ray absorptiometry [DEXA] was performed. Osteocalcin [OC], alkaline phosphatase [ALP], free galactosyl hydroxylysine [Gal-Hyl], calcium [Ca], inorganic phosphorus [P] and estradiol [E[2]] were measured in serum, whereas, deoxypyridinoline [Dpd] and creatinine levels were measured in urine. Simultaneously both osteopenic and osteoporotic groups showed significant decreases in BMD when compared to the controls. Osteocalcin, ALP and Gal-Hyl showed significant increase [p<0.0001] among the osteopenic and osteoporotic groups versus the control group. Significant decrease in E[2] levels were obvious among the osteopenic [p<0.0001] and osteoporotic [p<0.0001] women when judged against the controls. Urinary Dpd was significantly increased in the osteopenic and osteoporotic groups [p<0.001]. In osteoporotic group, significant negative correlations were observed between OC and BMD. Positive correlations were detected among the osteoporotic group between OC and ALP and between OC and Gal-Hyl. High significant negative correlations were confirmed between E[2] and OC among both the osteopenic and the osteoporotic groups. Also, a significant negative correlation was established between E[2] and Dpd in the osteoporotic group. In comparing between osteopenic and osteoporotic groups, significant decrease was recognized in BMD and significant increase was predicted regarding ALP, [p<0.05], Gal-Hyl [p<0.0001] and Dpd [p< 0.001]. Urinary Dpd may be a simple indicator for osteoporosis in postmenopausal women; however, screening should include the measurement of serum estradiol, galactosyl hydroxylysine, alkaline phosphatase and Osteocalcin to increase the sensitivity and specificity of primary screening to identify the groups at higher risk of osteoporosis which is the keystone in prevention of disabling fragility fractures