The association of serum osteoprotegerin and osteoporosis in postmenopausal hemodialysis patients: a pilot study.
OBJECTIVE
Osteoprotegerin (OPG) is a potent inhibitor of osteoclasts and plays an important role in bone metabolism. Relatively high serum levels of OPG have been observed in postmenopausal women with osteoporosis compared with age-matched controls. No data, however, are available on the relationship between low bone density and serum OPG levels in postmenopausal hemodialysis (HD) patients.


METHODS
The enrolled subjects included 28 postmenopausal HD patients and 28 age-matched postmenopausal women with normal renal function as controls. Bone mineral density (BMD) was measured by dual energy x-ray absorptiometry (DEXA) in both hips. Low BMD was defined as femoral neck T-score <-2.5. Serum OPG levels were measured using a commercial enzyme-linked immunosorbent assay (ELISA) kit.


RESULTS
Eight of the age-matched postmenopausal controls (28.6%) and 12 of the postmenopausal HD patients (42.9%) had low BMD. There was no statistically significant difference in low BMD between postmenopausal HD patients and age-matched postmenopausal patients (p = 0.263). The serum OPG level was significantly higher in the postmenopausal HD group (p < 0.001). Increased serum OPG (p = 0.017) and decreased serum albumin (p = 0.021) were significantly correlated with low BMD in postmenopausal HD patients. Univariate linear regression analysis showed that serum albumin (r = -0.455, p = 0.015) was negatively correlated, whereas age (r = 0.423, p = 0.025) and the length of time since menopause (r = 0.397, p = 0.036) were positively correlated with the serum OPG level in postmenopausal HD patients. Multivariate forward stepwise linear regression analysis showed that serum OPG (adjusted R(2) = 0.262, p = 0.003) was an independent predictor of low BMD in postmenopausal HD patients and explained 26.2% of the variance.


CONCLUSIONS
Serum OPG is associated with low BMD in postmenopausal HD patients.
Wu
Wen-Tien
WT
Institute of Medicine Science, Tzu Chi University, Hualien, Taiwan.
Lee
Ru-Ping
RP
Wang
Chih-Hsien
CH
Fang
Te-Chao
TC
Lin
Nien-Tsung
NT
Chen
Ing-Ho
IH
Hsu
Bang-Gee
BG
D000368:Aged; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000097:blood*; D053244:Osteoprotegerin / Q000097:blood*; D010865:Pilot Projects; D012044:Regression Analysis; D006435:Renal Dialysis; D012709:Serum Albumin / Q000032:analysis
D015415:Biomarkers; D053244:Osteoprotegerin; D012709:Serum Albumin