Grigorie D, Neacşu Elena, Marinescu Mirela, Popa Oana
Carol Davila University of Medicine and Pharmacy, Bucharest, Romania.
Rom J Intern Med. 2003;41(4):409-15.
Osteoprotegerin (OPG) is a recently identified citokine with an important role in bone remodeling, that acts as a decoy receptor for RANKL; OPG was shown to be an important inhibitor of osteoclast differentiation and activation. Leptin influences bone metabolism by acting on differentiated osteoblasts, having an anabolic effect on bone. The relationship between circulating OPG levels and osteoporosis in postmenopausal women is controversial. Thus, one of the aims of our study was to investigate the relationships between OPG levels and biochemical markers of bone turnover and bone density in women with and without osteoporosis. We have investigated 135 postmenopausal women, including a group with osteoporosis (n=76, mean age 59+/-8 years) and a group with severe osteoporosis (n=31, mean age 64+/-8 years), using healthy postmenopausal women (n=28, mean age 48+/-9 years) as controls. The serum concentrations of OPG were determinated by ELISA. Serum estradiol was measured by Enzyme Immunoassay (EIA). The markers of bone formation and resorption were measured by standard methods. Leptin was measured by ELISA. Bone mineral density at lumbar spine and femoral neck was measured by dual energy x-ray absorptiometry (DEXA). There was a significant positive association between serum OPG levels and age (r=0.27; p<0.001), both in the postmenopausal women as a whole and in the cohort with osteoporosis. Circulating OPG levels were significantly higher in both osteoporotic groups (p<0.005 and p<0.01, respectively) than in the control group. There were no significant associations between serum OPG levels and bone density, bone markers and serum estradiol. Serum leptin levels were significantly associated with age (r=0.18, p<0.03), estradiol (r=0.2, p<0.05) and BMD (r=0.25, p<0.008); there was no significant relationship between leptin and bone turnover markers. We conclude that serum OPG levels increase with age, both in healthy and osteoporotic postmenopausal women. This could represent a possible protective mechanism against bone loss. Serum leptin levels also increase with age and are positively associated with estradiol and BMD and not significantly associated with bone turnover markers.
骨保护素（OPG）是最近发现的一种细胞因子，在骨重塑中起重要作用，它作为核因子κB受体活化因子配体（RANKL）的诱饵受体；OPG被证明是破骨细胞分化和激活的重要抑制剂。瘦素通过作用于分化的成骨细胞影响骨代谢，对骨具有合成代谢作用。绝经后女性循环中OPG水平与骨质疏松症之间的关系存在争议。因此，我们研究的目的之一是调查有或无骨质疏松症的女性中OPG水平与骨转换生化标志物及骨密度之间的关系。我们调查了135名绝经后女性，包括一组骨质疏松症患者（n = 76，平均年龄59±8岁）和一组严重骨质疏松症患者（n = 31，平均年龄64±8岁），以健康绝经后女性（n = 28，平均年龄48±9岁）作为对照。采用酶联免疫吸附测定法（ELISA）测定血清OPG浓度。采用酶免疫测定法（EIA）测定血清雌二醇。采用标准方法测量骨形成和骨吸收标志物。采用ELISA法测定瘦素。采用双能X线吸收法（DEXA）测量腰椎和股骨颈的骨密度。在整个绝经后女性以及骨质疏松症队列中，血清OPG水平与年龄之间均存在显著正相关（r = 0.27；p < 0.001）。两个骨质疏松症组的循环OPG水平均显著高于对照组（分别为p < 0.005和p < 0.01）。血清OPG水平与骨密度、骨标志物及血清雌二醇之间均无显著相关性。血清瘦素水平与年龄（r = 0.18，p < 0.03）、雌二醇（r = 0.2，p < 0.05）和骨密度（r = 0.25，p < 0.008）显著相关；瘦素与骨转换标志物之间无显著关系。我们得出结论，在健康和患有骨质疏松症的绝经后女性中血清OPG水平均随年龄增加。这可能代表一种预防骨质流失的潜在保护机制。血清瘦素水平也随年龄增加，并且与雌二醇和骨密度呈正相关，与骨转换标志物无显著相关性。
