| OBJECTIVE:To investigate the correlations between serum osteoprotegerin (OPG) levels and bone mineral density (BMD) in postmenopausal women with type 2 diabetes(T2DM).METHODS:Subjects were 49 postmenopausal women with T2DM matched 40 healthy postmenopausal women with age, menopausal duration and body mass index. Serum OPG was measured by enzyme-linked immuno-sorbent assay (ELISA). BMD was measured at the posteroanterior lumbar spine 1-4, left femoral neck, femoral shaft, trochanter and total hip by dual-energy x-ray absorptiometry (DXA).RESULTS:(1) Compared with the control group, serum OPG levels were significantly higher (6.62±2.67 vs 3.44±2.10pmol/l, P<0.001) and BMD at posteroanterior lumbar spine 1-4, left femoral neck, femoral shaft, trochanter and total hip were significantly lower in T2DM group. (2) In T2DM subjects, bivariate correlation analysis showed there were positive correlation between OPG and fasting blood sugar,2 hour postprandial blood sugar, glycosylated hemoglobin A1c (HbA1c), urinary albumin excretion rate and high sensitivity C-reactive protein(hs CRP). Multiple regression analysis revealed that only hs CRP (bj'=0.349, P=0.024) was significant factor associated with OPG (Rc2=0.204, P=0.006). (3) In T2DM group, there was no correlation between serum OPG and any point BMD mentioned above. After being adjusted for age, fasting blood sugar,2 hour postprandial blood sugar, HbA1c, urinary albumin excretion rate and hs CRP, OPG levels in the osteoporosis subgroup were significantly higher than the non-osteoporosis subgroup (6.79±2.21 vs 6.56±2.83pmol/l, P<0.01). (4) In T2DM subjects, the levels of OPG tended to elevate with the increase of quartile HbA1c levels while serum OPG levels in the upper quartile group were significantly higher than that in the lower quartile group(8.07±3.35 vs 5.56±2.27pmol/l, P<0.05). However, the significant difference disappeared after being rectified by hs CRP.Conclusion:Postmenopausal women with T2DM and those suffered from osteoporosis have elevated level of serum OPG, but there may be no relationship between serum OPG level and BMD. Hs CRP, which reflected the state of inflammation, was significant related factor for serum OPG in postmenopausal women with T2DM. The results indicated that the significantly elevated serum OPG levels in postmenopausal women with T2DM was may be compensatory response to osteoporosis and chronic inflammation. |
