The effect of calcitonin on disuse atrophy of bone in the rat

In thirty female Sprague-Dawley rats the left hind leg was immobilized with plaster casts. According to treatment they were divided into the following groups: A) Control, no casts. B) No treatment. C) 50 MRC mU calcitonin (own preparation) in 5% gelatin subcutaneously per day. D) Vehicle alone subcutaneously. E) 50 MRC mU calcitonin (Ciba) in 5% gelatin subcutaneously per day. In addition, untreated rats without casts served as control (group A). After 6 weeks the femora and tibiae were X-rayed, weighed and examined histologically. The bones of the left and right legs did not differ in control group A. In groups B, C, D, and E a disuse osteoporosis had developed in the left legs (rarefication of trabecular bone volume of femur neck) which could not be seen in X-rays. Calcitonin treatment did not prevent the development of the bone atrophy. However, the pressure of the plaster casts had induced a periosteal apposition in some tibiae, and under calcitonin treatment the extent of this new formation in all femora and tibiae was markedly increased. The vehicle alone was ineffective. It can be concluded that whereas calcitonin is without effect on disuse osteoporosis, it probably favours new bone formation which is induced by other mechanisms.Supported by Deutsche Forschungsgemeinschaft, Bad Godesberg (Germany).     

降钙素基因多肽对骨代谢的影响

根据骨质疏松的发病机制不同,可分为原发性骨质疏松和继发性骨质疏松,原发性骨质疏松又可分为绝经性骨质疏松和老年性骨质疏松。骨质疏松是由多种发病因素共同作用的结果,在各型骨质疏松中,降钙素均发挥重要的调节作用。近年研究发现某些神经、血管活性肽,如降钙素基因多肽(Calcitonin gene-related peptide,CGRP）,在结构和功能上与降钙素具有一定的相似性。本文将降钙素基因多肽对骨代谢影响的相关研究进展作以下综述。     

Effect of calcitonin on bone histomorphometry and bone metabolism in rheumatoid arthritis

Summary Twenty-four women (mean age±SD 49±13 years) with classical or definite rheumatoid arthritis (disease duration 15±8 years) were treated with synthetic salmon calcitonin (SCT) nasal spray 200 IU three times a week for 3 months. Bone biopsies from the iliac crest were taken before and after SCT treatment. Histomorphometrical quantification of undecalcified bone sections was made using the manual point-counting method. SCT decreased the resorption surface of trabecular bone (ES/BS) significantly (P< 0.001). There was also a significant increase (P< 0.05) in trabecular bone volume (BV/TV) after 3 months of treatment, whereas no statistically significant changes were found in osteoid parameters. There were no significant changes in biochemical analyses of bone metabolism. We conclude that SCT might be useful in the prevention of bone loss in RA.     

Inhibitory effect of salmon calcitonin on bone resorption: Morphological study of the tibial growth plate in rats

Summary Salmon calcitonin (sCT) at doses of 100 and 50 UI given subcutaneously to growing rats produced in vivo evidence of osteoclastic activity inhibition. Histological assessment was carried out by measuring the perichondrial ring of Lacroix height, and a dose-correlated effect was found. These aspects were coupled with an increase in the osteoclast number and suggested that in studies with bone resorption inhibitors, morphological evaluation based on osteoclasts count is not reliable. The changes of the metaphysis suggested also that sCT affects the activity of hypertrophic chondrocytes of the growth plate. Plasma calcium levels did not differ significantly between treated rats and controls; an increased phosphatemia was observed in sCT-treated animals.     

An effective regimen of intranasal salmon calcitonin in early postmenopausal bone loss

Summary In order to devise a convenient and effective therapeutic regimen of intranasal salmon calcitonin (sCT) for the treatment of early postmenopausal bone loss, we studied the effects of a 1-year course of sCT nasal spray on vertebral mineral content (VMC), assessed by dual photon densitometry, and bone turnover in 21 early postmenopausal osteoporotic women. Subjects enrolled in the study had a value above the normal average of at least one index of bone turnover: whole body retention (WBR) of ^99mTc-methylenedichloro-bisphosphonate (^99mTc-MDP), serum bone gla protein (BGP), urinary hydroxyproline/creatinine excretion (HOP/Cr). After baseline evaluation, patients were randomized for treatment with either sCT (200 IU every other day) or plabebo. Treatment with sCT significantly increased VMC by 2.7±0.9% at 6 months, and 3.3±0.8% at 1 year, whereas a progressive decline was observed in the placebo group (-2.6±0.5%, and -3.5±0.5% after 6 and 12 months, respectively). These changes were associated with a progressive and significant reduction of all parameters of bone turnover in the sCT-treated patients, whereas no changes were detected in the control group during the study period. The differences between the two groups were significant after 1 year for VMC, BGP, and WBR (P<0.05, one-way analysis of variance). Thus, 200 IU intranasal sCT administered on alternate days is adequate to stop the fast bone loss occurring early after the menopause in women with high bone turnover rates. This therapeutical modality represents an important addition to the available pharmacologic spectrum for the prevention and treatment of postmenopausal osteoporosis.     

74例老年骨质疏松患者应用鲑鱼降钙素联合阿仑膦酸钠治疗的疗效观察

目的　评估联合应用鲑鱼降钙素与阿仑膦酸钠治疗缓解老年性骨质疏松症患者骨关节疼痛及血清骨钙素(BGP)、降钙素(CT)及骨密度(BMD)水平的变化。方法 联合应用鲑鱼降钙素和阿仑膦酸钠治疗本院收治的74例老年性骨质疏松症患者,给予鲑鱼降钙素50IU肌肉注射,隔日1次,连续使用15次后改为口服阿仑膦酸钠1粒/周,共经6个月治疗,采用数字模拟评分法(VAS)比较治疗前、后全身骨关节疼痛程度,治疗前、后骨钙素、降钙素及第2～第4腰椎(L2-4 )、股骨颈、Ward区骨密度水平的变化,并进行统计学分析。结果 鲑鱼降钙素联合阿仑膦酸钠治疗老年性骨质疏松症患者6个月后,对缓解骨关节疼痛症状疗效良好,治疗前与治疗后比较差异显著(P<0.01);治疗前后骨密度、血清骨钙素和降钙素水平均有显著差异（P<0.05）。结论 鲑鱼降钙素联合阿仑膦酸钠治疗老年性骨质疏松症使血清降钙素的水平明显升高,骨钙素水平明显降低,能显著减轻患者骨关节疼痛,改善症状,并增加骨密度,对老年性骨质疏松症有明显的疗效。     

Effect of intranasal salmon calcitonin therapy on bone mass and bone turnover in early postmenopausal women: A dose-response study

We examine the dose-related effect of intranasal salmon calcitonin (sCT) on the early postmenopausal bone loss and bone turnover; a 2-year, prospective, randomized, double-blind, placebo-controlled study was carried out with 134 healthy women who had passed a natural menopause within 6 months to 3 years. The women were allocated randomly to 2 years of treatment with either 100, 200, or 400 IU of sCT given intranasally or placebo. All groups received a calcium supplement of 500 mg. Twenty-one women left the study before its end and 91 complied with the study criteria throughout. Bone mineral content/density of the distal forearm and lumbar spine and biochemical parameters of bone turnover were measured. Although the measurements after 24 months revealed no significant difference between groups in bone mineral density of the lumbar spine, the average changes over time revealed prevention of bone loss in the groups treated with 200 and 400 IU of sCT (0.2 to-0.6%) and declines of 0.8-1.7% in the groups treated with 100 IU of sCT and placebo (P<0.05–0.01; within-group testing). There was no dose-related response to sCT but there was a significant difference between the pooled groups treated with 200 plus 400 IU of sCT versus the 100 IU sCT and placebo-treated groups (P=0.030–0.005). The same difference between groups was seen for biochemical parameters of bone turnover (P=0.022–0.003). The biochemical parameters of bone turnover revealed decreases of 10–20% (P<0.001; within group testing) in the groups treated with the two highest sCT doses. It was concluded that nasal sCT in doses of 200 and 400 IU has some effect in women soon after the menopause—preventing the bone loss in the spine throughout the first year of therapy and lowering the bone turnover. It may be used as an alternative to hormone replacement when estrogens are contraindicated. The present data indicate that discontinuous strategies should be preferred.     

Acute effects of nasal salmon calcitonin on calcium and bone metabolism

Summary Effects of a single dose of 200 IU of nasal salmon calcitonin (SCT) on calcium metabolism and biochemical markers of bone turnover were investigated in 12 healthy male volunteers in a randomized, placebo-controlled, crossover design. The nasal spray was given in the morning, and subsequently blood and urine samples were collected for 26 hours. There was a significant decrease in serum ionized calcium with a nadir 4 hours after administration of nasal SCT accompanied by a significant increase in serum parathyroid hormone (P = 0.01) and serum calcitriol (P = 0.04). Nasal SCT did not reduce urinary hydroxyproline/creatinine. Urinary deoxypyridinoline/creatinine was lowered significantly 2 hours after administration of nasal SCT and throughout the first 24 hours, but remained unchanged for the last 2 hours. On a 24-hour basis, urinary deoxypyridinoline/creatinine decreased from 14.1 (3.5) nmol/mmol to 11.7 (3.2) nmol/mmol after nasal SCT (P = 0.04). Nasal SCT did not change the serum levels of alkaline phosphatase, osteocalcin, and the carboxyterminal propeptide of type 1 procollagen. The results indicate that nasal SCT given as a single dose provokes a modest decrease in bone resorption lasting several hours, but leaves bone formation unaffected.     

The effects of salmon calcitonin-induced hypocalcemia on bone metabolism in ovariectomized rats

The ovariectomized rat has proved to be a most useful model for preclinical testing of potential therapies for osteoporosis. We describe the immediate effects of a single treatment with salmon calcitonin (sCT) on calcium homeostasis and bone turnover markers in 6-month-old sham and ovariectomized (ovx) rats at 15 days postovariectomy. Rats were fasted for 24 h prior to and following administration of 0.3 µg/kg body weight sCT. Blood specimens were collected at 0 (pretreatment), 2, 4, and 8 h. Urine samples were collected during the intervening periods. sCT treatment produced a decrease in blood ionized calcium at 2 h posttreatment in sham and ovx rats (P < 0.001), which was exaggerated in the ovx rats (P < 0.001). Increased parathyroid hormone (PTH) levels (P < 0.001) accompanied the hypocalcemia in ovx rats. Furthermore, PTH levels were significantly higher in ovx rats compared with sham rats for the same ionized calcium range of 1.275–1.300 mmol/l (P < 0.05). sCT treatment in sham rats increased urine hydroxyproline (UHyp) at 6 h posttreatment (P < 0.01). In conclusion, the calcitonin-induced hypocalcemia and secondary hyperparathyroidism was more pronounced in the ovariectomized rats, consistent with the actions of calcitonin in states of increased bone turnover induced by estrogen deficiency. This study highlights the importance of considering the actions of PTH and estrogen status when interpreting changes in calcium homeostasis and bone turnover following treatment with calcitonin in rodent models and provides further evidence for a potential role of estrogen in parathyroid function.     

降钙素受体基因频率与老年男性骨密度的关系

目的 探讨老年男性骨密度（BMD）与降钙素受体（CTR）基因频率和基因型频率的关系.方法 对深圳地区77例60岁以上男性,用双能X线骨密度仪测定髋部BMD值,分为骨质疏松组和非骨质疏松组,采用聚合酶链反应-限制性长度多态性（PCR-RFLP）技术检测CTR基因型.结果 老年男性CTR基因型频率分布依次为CC、CT、TT（分别占0.831、0.169、0）,C和T等位基因频率分别为0.916、0.084.不同基因比例：非骨质疏松组以CC型为多,骨质疏松组CT型为多（P＜0.01）.结论 男性CT基因型者可能为骨质疏松的易患人群.     

A new biochemical marker of bone resorption for follow-up on treatment with nasal salmon calcitonin

In a double-blind, placebo-controlled, randomized group comparison, new and specific biochemical markers for bone resorption as follow-up parameters on the therapeutic response to nasal salmon calcitonin (sCT) were evaluated. Evaluation took place at an outpatient clinic where osteoporosis was being researched. The subjects included 208 women aged 68–72 treated for 2 years with either 50 IU, 100 IU, or 200 IU of nasal sCT or placebo; all groups received a daily calcium supplementation of 500 mg. Only 164 women fulfilled the study as valid completers. Markers were applied to frozen urine samples of a previously published intervention study of a new fasting urinary (fU) biochemical marker for bone resorption (CrossLaps^TM, ELISA) and the urinary excretion of cross-links (pyridinoline and deoxypyridinoline) was measured, all corrected for creatinine. Bone mineral density of the lumbar spine and rates of vertebral and peripheral fractures were measured after 2 years of treatment. The creatinine corrected urinary pyridinoline, deoxypyridinoline, and CrossLaps showed maximum decreases of 10–43% (95% confidence interval-29.5% to 9.6% and -75.1% to 9.3%;P < 0.01-0.001) after 6–9 months, after which the response leveled off. A significant difference among the four treatment groups was seen in fU CrossLaps(P < 0.01). The changes in spinal bone mass were significantly related to the decreases in fU CrossLaps: women with the highest response in spinal bone mass had decreases in fU CrossLaps of 44% (-83.5% to 7.4%) and women without response of 5% (-57.6% to 99.9%)P 0.001). In women who fractured during the 2-year period, fU CrossLaps remained unchanged, whereas decreases of 30% (-75.1% to 44.7%) were seen in women who did not fracture(P = 0.002). The results suggest that biochemical markers can be used to determine the optimum treatment regimen of nasal sCT. The response of the new marker, fU CrossLaps, significantly reflects the responses in bone mass of the spine and fracture rates.     

鲑鱼降钙素联合海滨疗养因子对老年性骨质疏松症骨密度和骨转换指标影响的研究

目的观察鲑鱼降钙素联合青岛海滨疗养因子综合治疗方案对骨代谢的影响。方法研究组:口服钙尔奇D600 mg每日1次或其他钙片的同时,采用鲑鱼降钙素50IU肌肉注射,每日1次,连用2 w后改为隔日1次,连续使用6个月,同时联合海滨疗养因子,每周3~5次,每次1h以上;对照组:单纯采用口服钙尔奇D600 mg每日1次或其他钙片,连续使用6个月。观察两组及组间用药前后骨密度(BMD)、骨转换指标变化、骨痛和生活能力评价。结果 1骨密度变化:研究组治疗6个月后,腰椎L2-4、股骨颈部的骨密度较治疗前明显升高(P0.05),Ward区骨密度无显著性改变,而对照组各部位骨密度较用药前无明显改变(P0.05)。2血生化中血钙、血磷及碱性磷酸酶指标值:两组生化指标在治疗前后无显著差异(P0.05)。3治疗6个月后血清降钙素的水平明显升高,骨钙素水平明显降低。4疼痛程度改善情况:两组治疗前后疼痛分级比较,研究组疼痛明显改善。5生活质量改善情况(以生活能力提高为指标):研究组生活质量改善有效率为88.5%,而对照组仅为36.2%,两组有效率相比有显著差异(P0.01)。结论鲑鱼降钙素联合海滨疗养因子应用于老年性骨质疏松症患者,不仅能够增加骨密度而且可以减少骨质疏松症引起的疼痛,临床效果确切,患者依从性好,值得临床推广。     

Fluoride,parathyroid hormone and calcitonin: Inter-relationships in bone calcium metabolism

The influence of fluoride, parathyroid hormone and calcitonin on bone calcium metabolism was investigated in a bone culture system using half-calvaria of five-day old mice. Fluoride levels in the ash of half-calvaria of 0.007% (low fluoride group), 0.041% (moderate fluoride group), and 0.107% (high fluoride group) were achieved by varying the maternal and neonatal intake of fluoride. Fluoride inhibited the loss of calcium from bones cultured in control medium and parathyroid hormone-containing media, and promoted the uptake of calcium by bones cultured in medium containing calcitonin. Dead bones of the moderate and high fluoride groups took up more calcium from the culture medium than bones of the low fluoride group. Fluoride appears to exert its effect on bone calcium metabolism predominantly via a reduction in mineral solubility.Supported by Grant No. DE-01850, National Institute of Dental Research, Bethesda, Maryland.     

降钙素对正常成年雄性大鼠骨重建过程的影响

目的 在体研究降钙素对成年雄性大鼠松骨重建过程的影响,并分析其影响机制。方法 １２只大鼠平均分成对照组和降钙素组,后皮内注射鳗鱼降钙素１Ｕ／１００ｇ／日,连续２日。７日后取第４、５腰椎,行不脱钙骨组织切片,骨组织形态计量学分析,方差分析比较两组结果。结果 骨吸收陷窝表面、活性吸收表面、破骨细胞平均细胞核数,降钙素组明显小于对照组。类骨质表面、类骨质相对体积、类骨质厚度,降钙素组明显小于对照组,成     

Estimation of the effect of salmon calcitonin in established osteoporosis by biochemical bone markers

We reviewed data on 42 postmenopausal women with established osteoporosis (forearm fracture or a low bone mass0 who had been randomly treated for 1 year with either rectal salmon calcitonin (sCT), 100 IU daily (n=25) or nasal sCT, 200 IU daily (n=17) applying an estimation algorithm for bone loss rates. Both groups received a daily calcium supplement of 500 mg. A group of 18 age-matched women who received no treatment served as controls. The bone mineral content of the distal forearm (BMCarm) was measured every 3 months by single photon absorptiometry. The individual rates of change during the 1-year period were calculated by linear regression analysis (BMCarm). Bone loss rates were estimated initially and after 1 year of therapy by measurements of serum alkaline phosphatase, plasma bone Gla protein, and fasting urinary hydroxyproline and calcium (both corrected for creatinine excretion) according to the estimation algorithm. Both administration forms revealed significant control group-corrected decreases in serum and urine markers of bone turnover of 15–40% (P<0.05–0.01) and positive outcomes of 2% in BMCarm (P<0.01). The estimated effect on bone mass was expressed as the difference between the bone loss estimated after 1 year and initially (ESTBIO). A significant correlation was seen between BMCarm and ESTBIO (r=0.5, P<0.0001). We conclude that the effect of sCT on bone can be followed up by biochemical markers for bone turnover, i.e., by an annual blood and fasting urine sample, applying an estimation algorithm for the rate of bone loss.     

降钙素治疗骨质疏松症骨质量病变的研究

目的研究降钙素在骨质疏松症治疗中对骨密度bonemineraldensityBMD、骨强度及骨质疏松脆性骨折发生率的作用。方法为期1年的单中心、前瞻性、随机研究135例原发性骨质疏松症女性患者随机分成降钙素 钙剂组和钙剂组,进行开放、对比研究。降钙素 钙剂组66例鲑鱼降钙素50IU,肌内注射,第1周每天1次,第2周隔日1次,以后每周2次;同时口服元素钙600mg每天1次。钙剂组69例元素钙600mg每天1次。治疗前后分别进行血清钙、磷、碱性磷酸酶、骨钙素、尿羟脯氨酸、双能X线BMD和超声骨强度测量以及脊椎胸腰段正、侧位X线片比较。结果治疗1年后,降钙素 钙剂组53例获随访,与治疗前比较,腰椎BMD上升约1%P<0.05,髋部BMD无明显变化,桡骨和胫骨骨强度均明显改善;钙剂组59例获随访,腰椎、髋部BMD和桡骨、胫骨骨强度均较治疗前下降P<0.05。两组治疗前后各项生化检测指标无明显变化,骨质疏松脆性骨折的发生率钙剂组明显高于降钙素 钙剂组。结论降钙素治疗骨质疏松症有良好作用,不仅能有效地缓解骨痛,还能确实提高骨质量,降低骨质疏松脆性骨折的发生率。     

降钙素对卵巢切除大鼠骨转换的影响

尽管降钙素已在临床用于防治骨质疏松症，但其对骨转换的影响并未阐明，为此本实验以骨组织形态计量学为手段，观察了降钙素对卵巢切除大鼠小梁骨体积和骨转换的影响。实验分三组：卵巢切除后用降钙素组、卵巢切除后用生理盐水组和假手术组。取胫骨干骺端作不脱钙骨切片，行骨组织计量学测定。结果表明，与假手术组相比，卵巢切除后用生理盐水组其小梁骨体积明显下降，破骨细胞表面积、成骨细胞表面积、类骨质表面积、矿化表面积、矿化沉积率和骨形成率均明显升高。相反，卵巢切除后用降钙素组其小梁骨体积恢复正常，骨转换指标也接近假手术组。说明降钙素不仅抑制卵巢切除大鼠骨吸收，而且抑制其骨形成，使骨转换降低，从而预防卵巢切除大鼠骨丢失。     

Total and regional bone mineral content and fracture rate in postmenopausal osteoporosis treated with salmon calcitonin: A prospective study

Seventy-two postmenopausal osteoporotic women having more than one nontraumatic vertebral crush fracture were studied. Thirty-six of them, aged 68.8±1.2 years (18±4 YSM-years since menopause), were treated with 100 IU/day of salmon calcitonin i.m. plus 500 mg of elemental calcium for 10 days each month. The remaining 36 patients, aged 69.6±1.4 years (19±3 YSM), were given only 500 mg of elemental calcium for 10 days each month. All patients underwent clinical and analytical evaluation every 3 months. Radiological evaluation, assessment of vertebral deformities, and metacarpal radiogrammetry were done every 6 months. Densitometric measurements of total and regional bone mass were made every 12 months. At 24 months, the calcitonin group showed a 60% reduction in the number of new fractures and the group receiving only calcium had a 45% increase (P<0.001). The incidence of vertebral fractures was 0.07 per patient-year in the group treated with calcitonin and 0.45 per patient-year in the group treated with calcium (P<0.001). At 2 years, the calcitonin group showed a 12% increase in cortical bone mass on metacarpal radiogrammetry, a 16% increase in the axial skeleton on trunk densitometry, a 3.5% increase in total body bone mineral content, a 30.7% increase in pelvic bone mineral content, and a 6.2% increase in arm bone mineral content (all P<0.001). In the group treated with calcium alone there was a loss of bone mass in every region. These findings suggest that salmon calcitonin is effective in the treatment of osteoporosis and show that it acts on cortical and trabecular bone.     

Effect of diphosphonates and calcitonin on the chemistry and quantitative histology of rat bone

Young male rats were treated with one of three diphosphonates, disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP), disodium dichloromethylene-diphosphonate (Cl₂MDP), or disodium methane-1-cyclohexyl-1-hydroxy-1,1-diphosphonate (MCHDP), or with porcine calcitonin. Changes in the length weight, calcium, phosphorus, and ash of the femora and in plasma calcium, phosphate and alkaline phosphatase were measured. Bone formation rate was measured histologically in the tibial diaphysis using tetracycline markers. The lower dose (0.01–1mg P/kg/day s.c.) of the phosphonates, which block immobilization osteoporosis and reduce bone turnover measured by⁴⁵Ca kinetics, did not cause marked changes in the composition of the femora or in plasma values. This suggests that, at these doses in intact animals, the diphosphonates similarly reduce both resorption and mineralization rates. Higher doses of EHDP and MCHDP (10 or 30 mg P/kg/day s.c.) impaired bone growth both in length and width and inhibited mineralization of new cartilage and osteoid. The total calcium content of the bones decreased but the plasma values remained unchanged. Cl₂MDP did not impair mineralization at equivalent doses. EHDP, unlike Cl₂MDP, therefore seems to have two effects on bone. At lower doses it reduces bone turnover rate; but at higher doses it also directly prevents the full mineralization of new matrix. This difference between the effects of EHDP and Cl₂MDP may be important.     

降钙素受体基因多态性与中国绝经后妇女骨密度的Meta分析

目的系统评估降钙素受体(CRT)基因多态性与中国绝经后妇女骨密度的关系。方法计算机检索Pubmed、Embase、Web of science、Cochrane library、中国知网(CNKI)、维普(VIP)、万方数据库及中国生物医药文献数据库(CBD),收集有关CRT基因多态性与中国绝经后妇女骨密度的关系的文献,按照纳入和排除标准筛选文献并提取数据,采用Rev Man5.3、Stata12.0软件进行Meta分析,计算合并加权均数差(WMD)值和95%CI,并采用Begg检验和Egger检验进行发表偏倚评价,逐一排除法进行敏感性分析。结果共纳入7篇文献,累计病例1702例。Meta分析结果显示CRT基因多态性与北方绝经后妇女L2-4、大转子、Ward三角骨密度有关(P0.05),与南方绝经后妇女大转子骨密度有关(P0.05)。北方绝经后妇女CRT CC基因型大转子处骨密度较高(CC vs CT:WMD=0.05,95%CI=0.03~0.08,P0.00001;CC vs CT+TT:WMD=0.04,95%CI=0.01~0.07,P=0.003),南方绝经后妇女CRT CC基因型大转子处骨密度则相反(CC vs CT:WMD=-0.35,95%CI=-0.66~-0.03,P=0.03;CC vs CT+TT:WMD=-0.36,95%CI=-0.67~-0.05,P=0.02)。结论 CRT基因多态性可能与中国绝经后妇女骨密度有关,可作为预测骨质疏松和骨折风险的遗传指标。