Effect of / 生物医学与环境科学（英文）

Objective@#This study aimed to investigate the effects of @*Methods@#In this study, 0.1% DMG was supplemented in 20% casein diets that were either folate-sufficient (20C) or folate-deficient (20CFD). Blood and liver of rats were subjected to assays of Hcy and its metabolites. Hcy and its related metabolite concentrations were determined using a liquid chromatographic system.@*Results@#Folate deprivation significantly increased pHcy concentration in rats fed 20C diet (from 14.19 ± 0.39 μmol/L to 28.49 ± 0.50 μmol/L; @*Conclusion@#DMG supplementation exhibited hypohomocysteinemic effects under folate-sufficient conditions. By contrast, the combination of folate deficiency and DMG supplementation has deleterious effect on pHcy concentration.

Relatively high bone mineral density in Chinese adolescent dancers despite lower energy intake and menstrual disorder / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>The effect of dietary restriction, intense exercise and menstrual dysfunction on bone mineral density remains controversial. The aim of this study was to assess the skeletal health status and relationship between bone mineral density and nutrient intake, menstrual status, estrogen level and other factos in Chinese adolescent dancers.</p><p><b>METHODS</b>Sixty dancers and 77 healthy controls underwent measurements of bone density, body composition, and estrogen level. Nutrient intake, menstrual status and physical activity were assessed with questionnaires. The correlation between these factors were analyzed.</p><p><b>RESULTS</b>The dancers under study had a significantly lean body mass index (18.3 +/- 1.4 kg/m2 vs. 21.7 +/- 3.1 kg/m2), lower percentage of body fat (0.25 +/- 0.05 vs. 0.34 +/- 0.04) and later age at menarche (14.0 +/- 0.9 y vs. 13.0 +/- 1.3 y), and the estrogen level, daily calorie and fat intake in them were also lower than in the controls. All the dancers undertook intensive physical activity every day and up to 69% of them suffered from irregular menarche. Yet they had relatively high BMD and BMC of the total body and legs than the controls after adjusting for BMI and age. Site-specific BMD was positively correlated to BMI, body composition and training hours per week and negatively correlated to the age at menarche and menstrual frequency.</p><p><b>CONCLUSIONS</b>The relatively high BMD and BMC of the dancers at the total body and legs were probably caused by high levels of weight-bearing physical activity. To ameliorate disordered eating, especially low energy intake might be helpful to prevent the Triad and to improve the bone health in adolescent dancers.</p>

Relationship between estrogen receptor gene Px haplotype and the effect of calcium and soy isoflavone supplementation on bone mineral density of Chinese postmenopausal women / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the relationship between estrogen receptor gene Px haplotype and the effect of calcium and soy isoflavone supplementation on bone mineral density (BMD) of Chinese postmenopausal women.</p><p><b>METHODS</b>It was a randomly controlling test for 12 months. The Pvu II and Xba I polymorphisms of ER-alpha gene were detected by using restriction fragment length polymorphisms (RFLP) in 691 Chinese postmenopausal women, aged 45-65 years. In 497 carriers of definitive Pvu II-Xba I haplotype, 93 subjects were chosen randomly. BMD was measured by dual energy X-ray absorptiometry (DXEA). According to BMD T score in any skeleton site of 81 subjects at baseline, 29 subjects with T > or = -1.5 were grouped into observation group, and 52 subjects with T < -1.5 were randomly assigned into two intervention groups and received either a 100 mg soy isoflavone and 440 mg Ca and 100 IU VD supplement/d (n = 26) or 440 mg Ca and 100 IU VD supplement/d (n = 26). BMD of the whole body, lumber (L2-L4), and hip were measured at baseline and after 12 months.</p><p><b>RESULTS</b>After one year fellow-up, the BMD at L2-L4, femur neck site and whole body were significantly decreased as compared with those of baseline (P < 0.05, change percent of BMD as follows: -3.31%, -3.09%, -1.88%) in observation group, and the whole body BMD was significantly lower at 12 month than that at baseline in subjects with Px haplotype (percent change was -2.44%, P < 0.05), but no difference was found in subjects without Px haplotype. Whole body and femur neck BMD were significantly decreased in both Ca group and Ca + soy isoflavone group, but no significant difference of change percent between two groups. There were no significant changes in L2-L4 and trochanter BMD irrespective of treatment. ER-alpha Px haplotype had no effect on the changes in BMD in both Ca group and Ca + soy isoflavone group.</p><p><b>CONCLUSION</b>The rate of bone loss in Chinese postmenopausal women seems to haverelation to ER Px haplotype. Calcium supplementation for 1 year might lower the bone loss rate, but soy isoflavone supplementation for 1 year had notshowu no effects. The effect of supplementation had no relationship with ER Px haplotype.</p>

Study on the association between estrogen receptor-alpha gene polymorphisms and pubertal skeletal developmental status in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the association between estrogen receptor-alpha (ER-alpha) gene polymorphisms, pubertal bone mineral density (BMD) and bone turnover markers, to better understand the frequencies of ER-a genotypes.</p><p><b>METHODS</b>The ER-alpha Pvu II and Xba I genotypes were determined by PCR-RFLP in 158 healthy adolescent girls (12-14 years old) while BMD was measured by dual-energy X-ray absorptiometry (DEXA). The bone turnover markers (BAP, BGP, TRACP) and calcium adjust hormone (25-OH-VitD, E2) were detected by ELISA. The relationship among BMD, bone turnover markers, and polymorphisms of ER-a were examined.</p><p><b>RESULTS</b>(1) Although the bone turnover markers had a trend in ER-alpha Pvu II genotypes as pp>PP>Pp but no significant difference was found (P > 0.05). There were no significant differences found among Xba I genotypes and between Px haplotype and non-Px haplotype. (2) No association was noticed between ER-a genotype and BMD at any site of the forearm and the whole body. Compared with non-Px haplotype, the Px haplotype had lower BMD, but there was no significant difference noticed (P > 0.05).</p><p><b>CONCLUSION</b>ER-alpha gene Pvu II and Xba I polymorphism seemed not potentially influence on BMD and bone turnover markers in the pubertal girls in Beijing, suggesting that it might not be the major genetic factor regarding this population.</p>

Relationship between the absorption of dietary calcium and the Fok I polymorphism of VDR gene in young women / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the relationship between the absorption of dietary calcium and VDR (Vitamin D(3) receptor, VDR) gene RFLPs in Chinese young women with representative diets.</p><p><b>METHODS</b>Forty subjects were selected from three hundred young female students aged 18 - 23 years old. After identifying the VDR gene Fok I RFLPs, the subjects were given the representative diets during the 3-day adaptation period and the 12-day metabolism period. The copy food and drinking for measurement of nutrients and also the complete feces each day were collected. The dietary calcium absorption of each subject was examined and calculated.</p><p><b>RESULTS</b>As expected, the intake of dietary calcium in subjects is close to the results set by the of National Nutrition Investigation in 1992 (from young women at 17 year old) or the daily reference intake (DRI) for adult woman; the difference of the absorption of dietary calcium among VDR gene RFLPs in young women was observed: ff < Ff < FF, (28.7 +/- 10.5)%, (30.4 +/- 15.9)% and (40.6 +/- 11.0)% respectively; only significant difference between FF genotype and Ff genotype, P < 0.05.</p><p><b>CONCLUSION</b>Our results were consistent with those gained from the previous studies on children about the relationship between the absorption of dietary calcium and VDR (Vitamin D(3) receptor, VDR) gene RFLPs, and now it might occur in young women. Further studies need to be taken by using stable isotope and increasing subjects in young women.</p>