陕西省育龄妇女围孕期增补叶酸对新生儿出生体重的影响

目的 探讨陕西省育龄妇女围孕期增补叶酸对新生儿出生体重的影响。方法 采用分层多阶段随机抽样方法,以问卷调查方式收集2010-2013年陕西省怀孕且结局明确的育龄妇女及其子女的相关信息。将新生儿出生体重和母亲围孕期是否增补叶酸分别以因变量和自变量纳入多重线性回归及分位数回归模型,并控制相关混杂因素。结果 多重线性回归结果显示,围孕期增补叶酸者子女的出生体重高于未增补者,平均提高29.56 g（B=29.56,t=4.69,P<0.01）。分位数回归结果显示,当新生儿出生体重处于q=0～0.55、q=0.65、q=0.75～0.80百分位点时,增补过叶酸的母亲所生育子女的出生体重高于未增补者,差异有统计学意义,且体重提高的幅度不一致,随着出生体重百分位点的增高,增补过叶酸的母亲所生育子女的出生体重与未增补者相比提高幅度逐渐减小。结论 围孕期增补叶酸可以提高新生儿出生体重,对体重较轻的新生儿影响更大,体重较重的新生儿影响较小甚至无影响。     

ARIMA乘积季节模型在陕西省手足口病预测中的应用

目的 应用自回归求和移动平均（ARIMA）乘积季节模型预测陕西省手足口病发病人数。方法 利用R软件对2009年1月至2015年6月手足口病数据构建ARIMA乘积季节模型,同时利用2015年7-12月实际发病人数与模型拟合数据比较,评价模型的预测性能,预测2016-2017年的手足口病发病人数。结果 陕西省手足口病发病人数具有明显的季节性,建立了ARIMA（2,1,0）×（1,1,0）₁₂乘积季节模型,预测方程为（1-B）（1-B₁₂）Ln（X_t）=（（1-1.000B）/（（1-0.532B-0.363B²）（1-0.644B₁₂-0.454B₁₂²）））ε_t,与2015年7-12月实际发病人数比较,绝对误差的平均值为531.535,相对误差的平均值为0.114,预测2016-2017年陕西省手足口病发病人数与2015年基本保持一致。结论 ARIMA（2,1,0）×（1,1,0）₁₂乘积季节模型可用于陕西省手足口病的发病人数预测。     

High frequency of maternal vitamin B12 deficiency as an important cause of infantile vitamin B12 deficiency in Sanliurfa province of Turkey

Summary Background Vitamin B₁₂ deficiency in infancy may cause failure to thrive, severe neurological disorders and megaloblastic pancytopenia. It is well known that infants born with deficient vitamin B₁₂ storage have increased the risk of vitamin B₁₂ deficiency. Vitamin B₁₂ deficiency is more prevalent in infancy in Sanliurfa province (at the southeast region of Turkey). Aim of the study The aim of this study was to determine the frequencies of vitamin B₁₂, folic acid and iron deficiencies in pregnants and their babies at birth and to what extend the mothers’ deficiency becomes effective on babies’ deficiencies. Methods The study groups were constituted by 180 pregnant women and their single and term babies. Venous blood samples of pregnants were obtained 1–3 h before delivery and babies’ cord bloods were collected at birth. Vitamin B₁₂ and folic acid levels were measured with electro chemiluminiscence method; serum iron and iron binding capacities were measured by colorimetric method and complete blood counts were performed by automatic blood counter. Results Mean vitamin B₁₂ levels in maternal and cord blood serum were 130 ± 61.7 pg/ml and 207 ± 141 pg/ml; mean folic acid levels were 8.91 ± 6.46 ng/ml and 17.8 ± 11.8 ng/ml; mean serum iron levels were 56.9 ± 37.5 μg/dl and 147 ± 43.2 μg/dl; and mean transferrin saturations were 11.8 ± 8% and 65.6 ± 24%, respectively. There were vitamin B₁₂ deficiency (<160 pg/ml) in 72% of the mothers and 41% of the babies, and severe deficiency (<120 pg/ml) in 48% of the mothers and 23% of the babies. Folic acid deficiency was found in 12% of the mothers, but was not found in the babies. There were iron deficiency in 62% of the mothers and 1% of the babies. There were statistically significant correlation between maternal and cord blood serum vitamin B₁₂ levels (r = 0.395, P < 0.001) and folic acid levels (r = 0.227, P = 0.017), while there were no correlation between maternal and cord blood iron levels and transferrin saturations. Conclusion The study results showed that vitamin B₁₂ deficiency is prevalent in pregnants in this region and that 41% of infants have born with deficient vitamin B₁₂ storages. Therefore, prophylactic use of vitamin B₁₂ by pregnant women in Sanliurfa and other poor communities could have considerable benefits to prevent vitamin B₁₂ deficiency and its complications in infants.     

极低出生体重早产儿血清磷、骨碱性磷酸酶、25-羟基维生素D水平动态变化分析

目的 调查分析极低出生体重早产儿血清磷(P)、骨碱性磷酸酶(BALP)、25-羟基维生素D[25-(OH)D₃]水平动态变化,为临床早产儿代谢性骨病的早期预防提供指导。方法 选择入住烟台山医院新生儿科病房且符合入选标准的110例新生儿为研究对象,其中极低出生体重早产儿60例(病例组),足月产儿50例(对照组),分别于出生后1、4、12周空腹采取静脉血2 ml,测定血清P、BALP、25-(OH)D₃水平,分析骨代谢指标的变化情况。结果 病例组25-(OH)D₃水平增长速度低于对照组;两组血清P水平无明显变化。与对照组比较,病例组出生后1、4、12周血清BALP水平均显著性偏高;出生后第12周25-(OH)D₃水平的差异有统计学意义,其中病例组异常率达26.7%,对照组异常率为0。结论 极低出生体重早产儿(病例组)出生后追赶性生长过程中血清BALP、25-(OH)D₃水平与足月儿(对照组)有明显差异,提示该两项指标检测有助于极低出生体重儿代谢性骨病的早期发现及干预,其中以血清BALP指标敏感性较好。     

叶酸、维生素B12和B6联合使用对心脑血管病发生风险影响随机对照试验的Meta分析

目的 评价联合补充叶酸、维生素B12和B6对心脑血管疾病发生风险的影响。方法 检索1980-2014年有关补充叶酸、维生素B12和B6与心脑血管疾病发生关系的随机对照试验文献,筛选符合条件的研究。研究指标包括心脑血管疾病事件、心肌梗死及中风,效应指标为反映发生风险的相对危险度（RR）及其95%CI。运用Meta分析方法进行效应综合,并做亚组分析和敏感性分析。采用Jadad评分对文献质量进行评价。结果 共纳入11项随机对照试验研究,包含26 395名研究对象。有8项研究综合显示3种B族维生素联合使用对心脑血管疾病事件的发生无显著影响（RR=1.00,95%CI：0.94～1.07）;9项研究综合显示3种B族维生素联合使用对心肌梗死的发生无显著影响（RR=1.03,95%CI：0.94～1.13）。9项研究综合显示3种B族维生素联合使用可使中风的发生风险降低14%（RR=0.86,95%CI：0.78～0.95）。维生素B合剂组与对照组同型半胱氨酸水平比较,联合服用叶酸、维生素B12和B6能使同型半胱氨酸水平降低2.53 μmol/L（95%CI：-3.93～-1.12）;亚组分析显示,随访时间、维生素剂量、疾病史均对心脑血管疾病事件的研究结论无显著影响;而中风的亚组分析显示,随着随访时间延长,补充B族维生素能降低中风的发生风险,叶酸和维生素B12在小剂量下预防中风的作用更为显著,而维生素B6随着剂量的增加效果显著,有心脑血管病史者联合补充B族维生素降低中风风险的效果较好。结论 联合补充叶酸、维生素B12和B6对心脑血管疾病事件、心肌梗死的发生无显著影响,但可以降低中风发生的风险和同型半胱氨酸的水平。     

柳州市1998－2012年新发现HIV基因亚型变化及HIV感染者首次CD4+T淋巴细胞计数比较

目的 分析柳州市1998－2012年新发现HIV基因亚型变化,比较HIV感染者首次CD₄⁺T淋巴细胞计数（CD₄）,为艾滋病防治提供参考依据。方法 选取我国艾滋病综合防治信息系统中1998－2012年柳州市新发现HIV感染者,对其血浆进行RNA提取、扩增、测序和分型。采用Coharan-Armitage趋势检验法分析HIV基因亚型变化的趋势,采用Wilcoxon秩和检验法分析比较HIV感染者的首次CD₄。结果 研究对象共有1 877例HIV感染者。1998－2012年,CRF01_AE、CRF01_AE（Cluster 1）和CRF07_BC亚型构成比分别从78.4%（76/97）上升至91.5%（1 441/1 574）、63.9%（62/97）上升至74.0%（1 164/1 574）和17.5%（17/97）下降至4.6%（72/1 574）,趋势性检验差异均有统计学意义（Z=4.632,P<0.001;Z=2.455,P=0.014;Z=-5.943,P<0.001）。CRF01_AE（Cluster 1）、CRF01_AE（Cluster 2）、CRF07_BC和CRF08_BC亚型HIV感染者首次CD₄的中位数及四分位数间距分别是230（83～375）、215（48～351）、365（254～503）和334（206～479）个/μl。CRF01_AE（Cluster 1）和CRF01_AE（Cluster 2）亚型HIV感染者的首次CD₄均Z=-4.795,P<0.001;Z=-4.238,P<0.001）。结论 1998－2012年柳州市新发现HIV感染者以CRF01_AE亚型为主并呈上升趋势,其首次CD₄较低,且新发现CRF01_AE亚簇的种类在增加,其亚簇构成比存在变化趋势。     

宁波市大气PM2.5污染对城区居民慢性阻塞性肺疾病门诊量影响研究

目的 探讨宁波市大气PM_2.5污染对城区居民COPD门诊量短期影响。方法 基于宁波市全民健康信息平台,收集宁波市4家综合性医院2014－2016年城区居民COPD逐日就诊资料、同期气象及大气污染数据,采用泊松回归广义相加模型,分析宁波市大气PM_2.5污染与居民COPD门诊量的关系及滞后效应。结果 宁波市大气PM_2.5每升高10 μg/m³在全年、冷季（11月至次年4月）和暖季（5－10月）条件下分别可造成COPD门诊就诊人次升高1.87%（95% CI：0.98%～2.76%）、2.09%（95% CI：1.11%～3.08%）和2.56%（95% CI：0.56%～4.59%）,冷季滞后第4天效应最强,暖季当天效应值最大,未见滞后效应。大气PM_2.5污染对不同人群就诊量影响均有统计学意义（P<0.05）,且滞后第4天效应最强,其中≥65岁和女性人群中效应更明显。引入PM₁₀、SO₂和NO₂后,PM_2.5浓度对当天的COPD门诊就诊量效应ER值均无统计学意义（P>0.05）,对滞后第4天COPD门诊量效应强度略有变化,差异均有统计学意义（P<0.05）。结论 宁波市大气PM_2.5浓度升高与居民COPD门诊就诊量增加相关,应采取有效预防措施加强对脆弱人群的保护,降低COPD发病风险。     

湖南省HIV-1低病毒血症患者的生存质量及影响因素调查

目的 了解湖南省艾滋病低病毒血症(low-level viremia,LLV)患者生存质量的影响因素,为艾滋病防治策略的制定提供依据。 方法 应用方便抽样的方式,采用自编的一般情况调查表和世界卫生组织生存质量测量简表(WHOQOL-HIV BREF)对44例LLV患者进行横断面调查,采用t检验、F检验、多元线性回归分析生存质量的影响因素。 结果 44例LLV人群中,男性29例(65.91%),45~59岁年龄组16例(36.36%),37例(84.09%)服药依从性较好,7例(15.91%)服药依从性差,存在漏服药物的情况。LLV患者生存质量总均分为(68.58±6.04)分,生理领域均分为(10.77±1.49)分。单因素分析显示,不同生活居住地、职业、月收入水平、是否出现药物不良反应患者的生理领域得分比较,差异均有统计学意义(均P < 0.05);多元线性回归分析显示不同文化程度(B_心理=0.449,P_心理=0.048;B_环境=0.851,P_环境=0.028)、月收入水平(B_独立性=1.072,P_独立性=0.006;B_环境=0.989,P_环境=0.026)、是否出现药物不良反应(B_生理=-1.665,P_生理=0.002)等是影响患者生存质量各领域的重要因素。 结论 LLV患者的生存质量得分较低,应更加重视文化程度低、收入水平低、出现药物不良反应的患者,改善其生活质量。     

河南省HIV感染长期不进展者及病毒控制者病例特征分析

目的 调查河南省HIV感染者中长期不进展者(LTNP)和病毒控制者(HC)存在情况及其病例特征。方法 利用我国艾滋病综合防治数据信息管理系统和河南省艾滋病检测实验室数据应用平台中的病例信息,及实验室检测结果判定HC和LTNP,并进行调查核实、样本采集和相关检测。结果 148例LTNP和HC中共随访到71例,其中LTNP有58例,HC有22例,同时是LTNP和HC有12例,仅是LTNP有46例,仅是HC有10例;男性50例(70.4%);≥40岁有55例(77.5%);均为汉族;职业为农民61例(85.9%);感染途径为既往有偿供血52例(73.2%);抗-HCV阳性56例(78.9%);CD₄⁺T淋巴细胞计数均值(四分位数)538(445~654) cell/μl,病毒载量的对数均值(四分位数)为3.14(2.03~3.82) log10 copies/ml。HC的病毒载量对数均值低于LTNP(P=0.001)。结论 河南省HIV感染者中LTNP和HC的病例特征显著,更精确的分类有助于下一步研究。     

柯萨奇B组病毒的血清学监测

本文报道应用微量中和试验检测163例健康人群的柯萨奇病毒B组3、4、5型的中和抗体水平。中和抗体阳性率以B₄为最高(92.02%),B₃次高(62.57%), B₅最低(29.45%). B₃中和抗体几何平均滴度为14.19, B₄为102.8, B₅为3.96。B₃中和抗体滴度以1~3岁组最高,以后随年龄增长而降低。B₄中和抗体滴度除19~45岁组略高外,其余各组抗体滴度很低。     

Prevalence of nutrient deficiencies in bariatric patients

ObjectiveThe aims of this study were to determine the prevalence of nutrient deficiencies in patients who present for bariatric surgery, assess nutritional status after surgery, and compare these with preoperative levels.MethodsA retrospective study was conducted to identify preoperative and 1-year postoperative nutrition deficiencies in patients undergoing bariatric surgery. The screening included serum ferritin, vitamin D, vitamin B₁₂, homocysteine, folate, red blood cell folate, and hemoglobin. Results were available for 232 patients preoperatively and 149 patients postoperatively. Two-tailed χ² tests and paired-sample t tests were used.ResultsPreoperatively, vitamin D deficiency was noted at 57%. The prevalence of abnormalities 1 year after roux-en-Y gastric bypass was higher compared with preoperative levels (P < .05). After surgery, anemia was detected in 17%, elevated homocysteine levels (women only) in 29%, low ferritin in 15%, low vitamin B₁₂ in 11%, and low RBC folate in 12%. Mean hemoglobin, ferritin, and RBC folate levels deteriorated significantly but remained well within normal ranges. The prevalence of vitamin D deficiencies decreased, but not significantly. In sleeve gastrectomy patients, mean ferritin levels decreased (P < .05), without any patient developing a deficiency.ConclusionVitamin D deficiency is common among morbidly obese patients seeking bariatric surgery. Because the prevalence of micronutrient deficiencies persists or worsens postoperatively, routine nutrition screening, recommendation of appropriate supplements, and monitoring adherence are imperative in this population.     

Established and Suspected Biomarkers of Cardiovascular Disease (CVD) Risk in Pre-Menopausal Lebanese Women

Cardiovascular disease (CVD) is known to be caused by both environmental and non-environmental factors and the contribution of these factors seems to vary among different populations. Major nutritional biomarkers of CVD in 290 Lebanese pre-menopausal women were assessed. Diabetes, folate, and vitamin B₁₂ deficiencies were rare (below 0.5%) among the subjects. Abnormalities in lipid profile were more common, in which 16.7% of subjects had low HDL-cholesterol. Vitamin B₆ deficiency was also present at 14.5%. Low levels of HDL (established biomarker) and vitamin B₆ (suspected biomarker) seem to be the major nutritional abnormalities in Lebanese females of childbearing age.     

Plasma cobalamin and folate and their metabolic markers methylmalonic acid and total homocysteine among Egyptian children before and after nutritional supplementation with the probiotic bacteria Lactobacillus acidophilus in yoghurt matrix

Objective To evaluate the biopotency of the viable probiotic Lactobacillus acidophilus (La1) in yoghurt matrix consumed by Egyptian children on their plasma vitamin B₁₂ and folate levels, and their metabolic markers methylmalonic acid (MMA) and total homocysteine (t-Hcy).

Methods A randomized nutritional supplementation trial (42 days duration) was performed in free-living children of both sexes (11 years old). The La1 in yoghurt matrix was administered to provide 10¹² colony-forming units/subject/day. Blood sampling for the analysis of plasma vitamin B₁₂, folate and t-Hcy was performed by standardized methods. Five-hour urine collection was used for the analysis of MMA and t-Hcy.

Results Initially 33.3% of the children presented with biochemical vitamin B₁₂ deficiency (<208 pg/ml), while one-fifth (21%) were biochemically deficient in folate (<3 ng/ml folate/ml plasma or 0.68 nmol/l). Fifty percent of the children presented with high plasma t-Hcy (>15.0 µmol/l). The daily consumption of the probiotic La1 yoghurt for 42 days significantly improved the mean levels of plasma vitamin B₁₂ (P<0.05) and folate (P<0.01) among the studied children compared with the respective baseline data. On the other hand, the average levels of plasma t-Hcy and urinary MMA decreased significantly (P<0.05) at the termination of the 42-day nutritional supplementation, compared with the respective initial mean levels. The consumption of the probiotic yoghurt was also associated with a significant (χ²=8.0; P<0.01) reduction in the percentage prevalence of anemia (hemoglobin <120 g/l).

Conclusion The long-term ingestion of viable probiotic La1 potentially promoted the overall nutritional status of the studied children.     

Biological Variability and Impact of Oral Contraceptives on Vitamins B6, B12 and Folate Status in Women of Reproductive Age

Vitamins B₆, B₁₂ and folate play crucial metabolic roles especially during the reproductive years for women. There is limited reporting of within-subject variability of these vitamins. This study aimed to determine the within and between subject variability in serum vitamins B₆, B₁₂, folate and erythrocyte folate concentrations in young women; identify factors that contribute to variability; and determine dietary intakes and sources of these vitamins. Data were obtained from the control group of a trial aimed at investigating the effect of iron on the nutritional status of young women (age 25.2 ± 4.2 year; BMI 21.9 ± 2.2 kg/m²). The coefficients of variability within-subject (CV_I) and between-subject (CV_G) for serum vitamins B₆, B₁₂ and folate, and erythrocyte folate were calculated. Food frequency questionnaires provided dietary data. CV_I and CV_G were in the range 16.1%–25.7% and 31.7%–62.2%, respectively. Oral contraceptive pill (OCP) use was associated (P = 0.042) with lower serum vitamin B₁₂ concentrations. Initial values were 172 ± 16 pmol/L and 318 ± 51 pmol/L for OCP and non-OCP users, respectively; with differences maintained at four time points over 12 weeks. BMI, age, physical activity, alcohol intake and haematological variables did not affect serum or erythrocyte vitamin concentrations. Vitamin B₁₂ intakes were derived from traditional and unexpected sources including commercial energy drinks. Young women using OCP had significantly lower serum vitamin B₁₂ concentrations. This should be considered in clinical decision making and requires further investigation.     

Iron, folate, and vitamin B 12 nutrition in pregnancy: a study of 1000 women from southern India

As part of a WHO collaborative programme the prevalence of anaemia was studied and the serum concentrations of iron, folate, and vitamin B₁₂ were measured in 1 000 pregnant women from southern India. The results of the study show a high prevalence of anaemia, resulting from iron and folate deficiency with iron deficiency predominating. Interrelationships between these nutrients and their effect on pregnancy and the fetus were investigated. The results indicate that, in comparison with populations in developed countries, there was a high prevalence of iron and vitamin B₁₂ deficiency in the community, but the state of folate nutrition was similar to that found elsewhere.     

The effects of exercise training and acute exercise duration on plasma folate and vitamin B12

BACKGROUND/OBJECTIVES

Energy production and the rebuilding and repair of muscle tissue by physical activity require folate and vitamin B₁₂ as a cofactor. Thus, this study investigated the effects of regular moderate exercise training and durations of acute aerobic exercise on plasma folate and vitamin B₁₂ concentrations in moderate exercise trained rats.

MATERIALS/METHODS

Fifty rats underwent non-exercise training (NT, n = 25) and regular exercise training (ET, n = 25) for 5 weeks. The ET group performed moderate exercise on a treadmill for 30 min/day, 5 days/week. At the end of week 5, each group was subdivided into 4 groups: non-exercise and 3 exercise groups. The non-exercise group (E0) was sacrificed without exercising and the 3 exercise groups were sacrificed immediately after exercising on a treadmill for 0.5 h (E0.5), 1 h (E1), and 2 h (E2). Blood samples were collected and plasma folate and vitamin B₁₂ were analyzed.

RESULTS

After exercise training, plasma folate level was significantly lower and vitamin B₁₂ concentration was significantly higher in the ET group compared with the NT group (P < 0.05). No significant associations were observed between plasma folate and vitamin B₁₂ concentrations. In both the NT and ET groups, plasma folate and vitamin B₁₂ were not significantly changed by increasing duration of aerobic exercise. Plasma folate concentration of E0.5 was significantly lower in the ET group compared with that in the NT group. Significantly higher vitamin B₁₂ concentrations were observed in the E0 and E0.5 groups of the ET group compared to those of the NT group.

CONCLUSION

Regular moderate exercise training decreased plasma folate and increased plasma vitamin B₁₂ levels. However, no significant changes in plasma folate and vitamin B₁₂ concentrations were observed by increasing duration of acute aerobic exercise.     

Vitamin B12 and Folic Acid Imbalance Modifies NK Cytotoxicity,Lymphocytes B and Lymphoprolipheration in Aged Rats

Different vitamin B₁₂ and folic acid concentrations could exacerbate the immune response. The aim was to evaluate different dietary folic acid and vitamin B₁₂ levels on the immune response in aged rats. Male Sprague Dawley aged rats were assigned to three folic acid groups (deficient, control, supplemented) each in absence of vitamin B₁₂ for 30 days. Several parameters of innate and acquired immune responses were measured. Serum and hepatic folate levels increased according to folic acid dietary level, while vitamin B₁₂ levels decreased. There was a significant decrease in natural killer cell-mediated cytotoxicity in the spleen for the vitamin B₁₂ deficient diet and folic acid control diet groups. Significant changes in CD45 lymphocyte subsets were also observed according to dietary imbalance. Lymphoproliferative response to concanavalin A and phytohemagglutinin did not differ significantly between groups. The spleen response to lipopolysaccharide increased significantly, but was unmodified for the other organs. An imbalance between dietary vitamin B₁₂ and folic acid concentrations alters some immunological parameters in aged rats. Therefore, the ratio between folate and vitamin B₁₂ could be as important as their absolute dietary concentrations.     

B vitamin supplementation improves cognitive function in the middle aged and elderly with hyperhomocysteinemia

Objective: An intervention study was performed to determine if supplement containing folic acid, vitamin B₆, and vitamin B₁₂ could improve cognitive function and lower homocysteine in middle-aged and elderly patients with hyperhomocysteinemia.

Methods: One hundred and four participants with hyperhomocysteinemia were recruited in Tianjin, China, aged 55–94 years old. Fifty-seven individuals with hyperhomocysteinemia were included in the intervention group (vitamin B group, which received 800 µg/day of folate, with 10 mg of vitamin B₆ and 25 µg of vitamin B₁₂) and 47 patients in the placebo group. The endpoint was the improvement in cognitive function as evaluated by Basic Cognitive Aptitude Tests (BCATs). All parameters were measured before and after the treatment period of 14 weeks.

Results: The BCAT total score and four sub-tests scores (digit copy, Chinese character rotation, digital working memory, and recognition of meaningless figure) of BCAT at 14 weeks significantly increased only for the vitamin B group. Serum total homocysteine (tHcy) levels significantly decreased in the intervention group, while serum concentrations of folate, vitamin B₆, and vitamin B₁₂ significantly increased in the intervention group.

Conclusion: The results demonstrated that supplement containing folate, vitamin B₆, and vitamin B₁₂ in middle-aged and elderly patients with hyperhomocysteinemia could improve their cognitive function partly and reduce serum tHcy levels.     

Plasma Vitamin B12 and Folate Alter the Association of Blood Lead and Cadmium and Total Urinary Arsenic Levels with Chronic Kidney Disease in a Taiwanese Population

Heavy metals causing chronic nephrotoxicity may play a key role in the pathogenesis of chronic kidney disease (CKD). This study hypothesized that plasma folate and vitamin B₁₂ would modify the association of CKD with total urinary arsenic and blood lead and cadmium levels. We recruited 220 patients with CKD who had an estimated glomerular filtration rate of <60 mL/min/1.73 m² for ≥3 consecutive months and 438 sex- and age-matched controls. We performed inductively coupled plasma mass spectrometry to measure blood cadmium and lead levels. The urinary arsenic level was determined using a high-performance liquid chromatography–hydride generator–atomic absorption spectrometry. Plasma vitamin B₁₂ and folate levels were measured through the SimulTRAC-SNB radioassay. Compared with patients with plasma vitamin B₁₂ ≤ 6.27 pg/mL, the odds ratio (OR) and 95% confidence interval of CKD for patients with plasma vitamin B₁₂ > 9.54 pg/mL was 2.02 (1.15–3.55). However, no association was observed between plasma folate concentration and CKD. A high level of plasma vitamin B₁₂ combined with high levels of blood lead and cadmium level and total urinary arsenic tended to increase the OR of CKD in a dose-response manner, but the interactions were nonsignificant. This is the first study to demonstrate that patients with high plasma vitamin B₁₂ level exhibit increased OR of CKD related to high levels of blood cadmium and lead and total urinary arsenic.     

Effects of dietary supplementation of high-dose folic acid on biomarkers of methylating reaction in vitamin B12-deficient rats

Folate is generally considered as a safe water-soluble vitamin for supplementation. However, we do not have enough information to confirm the potential effects and safety of folate supplementation and the interaction with vitamin B₁₂ deficiency. It has been hypothesized that a greater methyl group supply could lead to compensation for vitamin B₁₂ deficiency. On this basis, the present study was conducted to examine the effects of high-dose folic acid (FA) supplementation on biomarkers involved in the methionine cycle in vitamin B₁₂-deficient rats. Sprague-Dawley rats were fed diets containing either 0 or 100 µg (daily dietary requirement) vitamin B₁₂/kg diet with either 2 mg (daily dietary requirement) or 100 mg FA/kg diet for six weeks. Vitamin B₁₂-deficiency resulted in increased plasma homocysteine (p<0.01), which was normalized by dietary supplementation of high-dose FA (p<0.01). However, FA supplementation and vitamin B₁₂ deficiency did not alter hepatic and brain S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) concentrations and hepatic DNA methylation. These results indicated that supplementation of high-dose FA improved homocysteinemia in vitamin B₁₂-deficiency but did not change SAM and SAH, the main biomarkers of methylating reaction.