1、孕妇钙营养及钙需要的系列研究,研究背景,孕期钙营养需要的特殊性 成熟新生儿体内含钙约30g，孕末期需储钙约300mg/d； WHO/FAO制订孕期钙推荐供给量的依据包括是以非孕妇女为基础加上胎儿发育所需钙量；考虑钙的吸收率； 1988年中国营养学会制订钙RDA为1500mg/d;,研究背景,钙的供给现状 1992年全国营养调查显示，城乡人均钙摄入量为405.2mg/d，为RDA49.2%; 广东城乡居民人均钙摄入量为387.5mg/d，为RDA46.5%; 各地孕妇钙实际摄入量398721mg/d，为RDA 的1/31/2。,问题的提出,我国孕妇缺钙？ 我国孕妇对传统低钙膳食适应？ 传统低钙膳
2、食对孕妇、胎儿或新生儿有什么影响？,研究的实验设计,一、动物实验 以非孕雌性大鼠为对照； 用含钙1.0、0.25、0.05三种饲料干预妊娠大鼠至产后，观察不同钙供给时，妊娠大鼠钙代谢的差异； 钙代谢试验； 45Ca小肠吸收试验；,研究的实验设计,二、人体追踪研究 对象 36名孕18周妇女; 分组 I（传统膳食组） 钙摄入478.5 139.7 mg/d； II(膳食钙干预组) 传统膳食+45g奶粉，钙摄入823.982.0mg/d； III(膳食加钙剂联合干预组) 传统膳食+45g奶粉+600mg钙，钙摄入量1274.6147.8 mg/d;,研究的实验设计,二、人体追踪研究内容膳食钙干预，从
3、孕中至产后45天； 母体：钙代谢试验；相关生化指标；激素水平测定；产后骨密度； 子代：胎儿发育，新生儿体格；,一、妊娠机体对低钙供给的代谢改变,（一）动物试验 Table 1 Indices of calcium metabolism in pregnant rats（xs）n 1.0%Ca 0.25%Ca 0.05%CaDiet consumption(g/d) 30 14.73 1.57 16.28 2.68a 18.65 1.86a b Calcium intake(mg/d) 30 147.9218.33 39.246.76a 9.240.94a b Ca of feces(mg/d)
4、 21 115.8521.79 19.276.69a 13.101.69a b Ca of urine(mg/d) 21 0.520.06 0.380.07a - AA of Ca(% ） 21 21.490.48 49.546.14a - Retention of Ca(mg/d) 21 31.5614.70 19.597.62a -4.121.88Note: a: compared with 1.0%Ca, p 0.05; b: compared with 0.25%Ca, p 0.05;,一、妊娠机体对低钙供给的代谢改变,Table 2 Indices of calcium metabo
5、lism of rats in 24hoursGroup Diet intake Ca intake AA of Ca Retention of Ca(g) (mg) （%） (mg)No-preg- 1.0%Ca 12.091.31 121.0014.85 17.457.01 20.596.54 0.25%Ca 13.021.21 32.773.43 35.4011.42a 11.393.18a Pregnancy 1.0%Ca 14.731.57 147.9218.33 21.490.48 31.5614.70 0.25%Ca 16.282.68a 39.246.76a 49.546.14
6、a b 19.597.62a b Note：a: compared with1.0%Ca, p0.01; b: compared with No-pregnancy，p0.01;,一、妊娠机体对低钙供给的代谢改变,Table3 45CaCl2 uptake in duodenum, jejunum and ileum in pregnant rats (cpm/mg)1.0%Ca 0.25%Ca 0.05%CaDuodenum 95.9218.52 136.7523.93a 169.1935.41a b Jejunum 88.4318.32 124.8729.70a 155.2410.19a
7、b Ileum 92.7527.56 111.1228.25 152.5434.65abNote: n=10 ; a: compared with 1.0%Ca, p 0.05;b: compared with 0.25%Ca, p 0.05;,Fig.1 45CaCl2 uptake in duodenum, jejunum and ileum in pregnant rats,Note: n=10 ; a: compared with 1.0%Ca, p 0.05; b: compared with 0.25%Ca, p 0.05.,a,a,ab,a,ab,ab,一、妊娠机体对低钙供给的代
8、谢改变,妊娠、三种钙水平对肠道45Ca摄取力23析因分析 钙在十二指肠摄取力增高是妊娠和低钙供给共同作用的结果； 空肠和回肠摄取力增高主要是低钙供给的结果； 妊娠和低钙的共同作用增加了钙在肠道的吸收，包括肠道上段的主动吸收和下段的被动扩散； 低钙供给时主要增加肠道下段的被动扩散。,一、妊娠机体对低钙供给的代谢改变,(二)人体研究 Table 4 Calcium metabolism of the 3rd trimestrial pregnant womenGroup 1(12) Group II(12) Group III(11)Intake of Ca( mg/d) 565129 90971
9、 137125 Ca of feces (mg/d) 14667 30732 65193 Ca of urine (mg/d) 14863 28440 32484 Ca of retention(mg/d) 27174 31868 39639 AA of Ca(%) 74.686.3 66.034.3 52.57.0Note: compared with Group 1, p 0.05, p 0.01; compared with Group II, p 0.05, p 0.01; in ( ).n;,Fig.2 Calcium metabolism of the 3rd trimestria
10、l pregnant women Note: compared with Group 1, p 0.05, p 0.01; compared with Group II, p 0.05, p 0.01., , ,Fig.3 Calcium absorption of the 3rd trimestrial pregnant women Note: compared with Group 1, p 0.05, p 0.01., ,一、妊娠机体对低钙供给的代谢改变,小结 1. 低钙供给时, 孕及非孕大鼠饲料消耗增加，钙排出减少,肠道钙吸收率显著增加，这种改变孕鼠较非孕鼠更明显; 2.妊娠状态、低钙
11、供给，通过增加摄食量、调节肠道和肾脏的功能，使机体在有限的钙供给时储留更多的钙; 3.妊娠和低钙共同作用使钙在十二指肠摄取力增高,低钙供给主要使空肠和回肠摄取力增高; 4.妊娠和低钙的共同作用增加了钙在肠道上段的主动吸收，低钙供给时主要增加肠道下段的被动扩散。,二、孕期低钙摄入对骨健康的影响,(一)动物实验 Table 5 Contents of ash and calcium in femur of the pregnant rats1.0%Ca 0.25%Ca 0.05%CaWeight of femur(g) 0.440.04 0.400.06 0.380.04 Contents of
12、ash(mg) 0.260.02 0.240.04 0.220.02 Contents of Ca(mg) 96.437.5 75.182.2 66.8450.5Note: compared with 1.0%, p 0.05; compared with 0.25%, p 0.05;,二、孕期低钙摄入对骨健康的影响,(一)动物实验 Table 6 Contents of ash and calcium in femur(xs)No-pregnancy pregnancyGroup 1.0%Ca(7) * 0.25%Ca(7) 1.0%Ca(7) 0.25%(7)Weight of femur
13、(g) 0.450.02 0.420.02 0.440.04 0.400.06 Contents of ash(mg) 0.260.01 0.260.01 0.260.02 0.240.04 Contents of Ca(mg) 95.882.5 8.247.3 96.437.4 75.182.2 Note: compared with 1.0%Ca, p 0.05; compared with No-preg, p 0.01; in( )*： n;,二、孕期低钙摄入对骨健康的影响,(一)动物实验 1.相关分析 骨钙量与大鼠钙摄入量、机体钙贮留量均显著正相关（r=0.7527和0.7021,
14、p0.001）; 钙存留量与钙摄入量显著正相关（r=0.7519， p0.01）。 2.股骨病理改变当钙水平为0.25%时，可维持机体的正钙平衡，但出现明显的股骨钙动员的病理学体征。0.05%钙组，形态学上骨动员体征更为明显。,二、孕期低钙摄入对骨健康的影响,（二）人体研究 Table 7 Lumber bone mineral density in different groups (g/cm2)Position Group 1(12) Group II(12) Group III(11)Right spinea 0.8940.054 0.9550.054 1.0540.043 Latera
15、l middle spinea 0.6090.059 0.6680.046 0.7490.043 Lateral spinea 0.6400.039 0.6850.030 0.7580.033 Note: a, Average of L2L4; in ( ) n ; , compared with group 1,p0.05,p 0.01; b: compared with group II p0.05 ,p 0.01;,Right spine Lateral middle spine Lateral spine Fig.4 Lumber bone mineral density in dif
16、ferent groups Note: , compared with group 1,p0.05,p 0.01; b: compared with group II p0.05 ,p 0.01.,二、孕期低钙摄入对骨健康的影响,（二）人体研究 Table 8 BMD percentage of non-pregnancy of the same age Position Group 1(12) Group II(12) Group III(11)Right spinea 86.675.41 92.585.48 102.454.37 Lateral spinea 82.835.02 88.58
17、3.94 97.734.29 Average 85.146.61 90.746.53 100.445.19Note: a, Average of L2L4; in ( ) n ; , compared with group 1,p0.01; : compared with group II, p 0.01;,Right spine Lateral spine Average Fig.5 BMD percentage of non-pregnancy of the same ageNote: , compared with group 1,p0.01; : compared with group
18、 II, p 0.01.,二、孕期低钙摄入对骨健康的影响,（二）人体研究Table3 Weight and length of the newbornGroup n length(cm) weight (g) score of the riskI 12 51.33.5 3437293 82.53.4 II 12 53.32.7 3584365 86.74.4 III 11 53.82.4 3431287 87.33.4Note: Compared with group I, , p0.01;,二、孕期低钙摄入对骨健康的影响,小结 1.传统膳食(低钙摄入)，不影响胎儿及新生儿体格发育; 2.低钙
19、供给时，尽管母体钙代谢有一系列适应性改变，但钙存留量降低，股骨钙含量也减少; 3.传统膳食(低钙摄入), 腰椎各部位骨密度显著低于膳食钙干预组及膳食加钙剂联合干预组; 4.传统膳食(低钙摄入), 腰椎各部位骨密度下降至同龄非孕妇女85.14%; 膳食加钙剂联合干预(钙摄入1274.6147.8 mg/d) 可维持骨密度至同龄非孕妇女同等水平;,三、孕期钙代谢调节的相关因素,(一)骨钙素 Table9 Serum BGP contents in the pregnancy phases (xs ,g/L) Group 1(12) Group II(12) Group III(11)Middle
20、pregnancy 3.360.53 3.550.46 3.440.57 Later pregnancy 3.920.52 4.760.87 4.741.46 After parturition 4.740.61 6.360.93 a 6.201.01 aNote: in ( ) n ; , compared with Middle pregnancy, p0.05;,Middle pregnancy Later pregnancy After parturition Fig.6 Serum BGP contents in the pregnancy phases (xs ,g/L) Note
21、: , compared with Middle pregnancy, p0.05., a, a,三、孕期钙代谢调节的相关因素,二、雌激素 Table 10 Serum estradiol contents in the pregnancy phases (xs , pg/ml)Group 1(12) Group II(12) Group III(11)Middle pregnancy 730.9267.2 720.1279.1 742.1665.9 Later pregnancy 1731.5490.5 1502.6458.6 998.7226.2ba After parturition 4
22、26.2296.3 166.7179.4a 91.625.2 ANote: in ( ) n ; compared with Middle pregnancy, p0.01; compared with Later pregnancy, p0.01; compared with group1, a p 0.05, A p0.01; compared with group II, b p0.01;,Middle pregnancy Later pregnancy After parturition Fig.7 Serum estradiol contents in the pregnancy p
23、hases (xs , pg/ml) Note: compared with Middle pregnancy, p0.01; compared with Later pregnancy, p0.01; compared with group1, a p 0.05, A p0.01; compared with group II, b p0.01.ba,ba,a, A,三、孕期钙代谢调节的相关因素,相关分析 1.骨钙素与钙摄入量显著正相关（r=0.53, p0.001); 2.骨钙素与多部位骨密度正相关（r=0.55, p0.01）; 3.雌激素与钙摄入量显著负相关（r= -0.59, p0.01）; 4. 钙表观吸收率与雌激素显著正相关（r=0.52, p0.05） 5. 雌激素水平与侧位、侧位中心骨密度显著负相关(r分别为-0.60，-0.70, p0.01）;,三、孕期钙代谢调节的相关因素,小结 1.孕末期充足钙供给，雌激素分泌相对减少，骨钙素分泌增加, 腰椎骨密度增加; 2.孕末期低钙供给，虽雌激素分泌增加，钙的吸收增加，但骨钙素分泌下降，腰椎骨钙密度下降; 3.与孕末期相比，产后期各组雌激素水平显著下降，骨钙素水平显著升高, 雌激素水平下降、骨钙素水平升高与钙摄入量密切相关, 推测产后母体骨质的恢复依赖充足钙供给;,
