亚甲基四氢叶酸还原酶基因C677T多态性与胃癌易感性的关系

目的 研究亚甲基四氢叶酸还原酶（MTHFR）基因C677T多态性及其和烟酒嗜好相互作用与胃癌中易感性的关系。方法 在上消化道癌高发区江苏省淮安市进行病例对照研究（胃癌患者107例，对照人群200名）。调查研究对象的生活习惯，采用PCR－RFLP技术检测研究对象的MTHFR基因型。结果 （1）胃癌组中MTHFR变异基因型拥有者的比例79．4％，显著高于对照组的68．5％（x^2=4.15,P=0.0416)。MTHFR变异基因型拥有者发生胃癌的危险性显著升高（OR＝1.78,95%,CI:0.99-3.22；性别和年龄调整OR＝1．89，95％CI：1．08－3．32）。（3）在MTHFR变异基因型拥有者中，伴有吸烟习惯者发生胃癌的OR为7．72％（95％CI：2．23－26．79），伴有经常饮酒习惯者发生胃癌的OR为3．08％（9T％CI：1．30－7．23）。与不吸烟，不经常饮酒的野生型纯合子MTHFR基因型拥有者相比，伴有吸烟的经常饮酒习惯的MTHFR变异基因型拥有者发生胃癌的OR为13．96％（95％CI：2．76－70．46）。结论 MTHFR C677T变异基因型与胃癌的易感性有关；吸烟和饮酒与MTHFR变异基因型在胃癌发生中有明显的协同作用。     

中国农村人群高血压危险因素的meta分析北大核心CSCD

目的探讨中国农村人群高血压发病的主要危险因素,为今后防治提供依据。方法以高血压、农村、危险因素等为主题词或关键词,检索1998—2013年发表的有关中国农村人群高血压发病危险因素的病例对照研究,按照文献纳入与排除标准选择文献、评价质量,提取数据,采用RevMan5．1软件进行meta分析。结果共17篇文献符合条件纳入研究,meta分析结果表明各危险因素的合并OR值及95％a分别为：年龄（OR=1．07,95％CI：1．06—1．08）、BMI（OR=1．36,95％CI=1,27～1．45）、高血压家族史（OR=1．79,95％CI=1．34—2．39）、吸烟（OR=1．20,95％CI=1．07～1．34）、饮酒（OR=1．20,95％CI=1．14—1．27）、嗜盐（OR：1．28,95％CI=1．17—1．41）、高脂肪摄入（OR=1．17,95％CI=1．05—1．31）、文化程度高（OR：0．78,95％CI=0．71～0．87）、经济收入高（OR=0．90,95％CI=0．86—0．94）、锻炼（OR=0．81．95％CI=0．69～0．94）、腰臀比（OR=1．51,95％CI=1．2—1．89）、性别（OR：1．28,95％Cl=1．15-1．42）。结论高血压家族史、腰臀比、BMI、嗜盐、性别、吸烟、饮酒、高脂肪摄入、年龄为中国农村人群高血压发病的危险因素,文化程度高、锻炼、经济收入高则为保护性因素。     

胃癌发病危险因素的病例对照研究

目的 探讨胃癌发病的危险因素。方法 以本院确诊的70例胃癌病例作为病例组，按性别、年龄、民族、居住地作为配比条件选取70名健康人群进行1：1配对的病例配对研究。并将研究因素进行条件的Logistic回归分析。结果 多因素条件Logistic回归分析显示胃癌发病与保护因素新鲜蔬菜水果(OR=0．232，95％CI=0．067—0．797)、危险因素盐腌食物(OR=7．215，95％CI=1．149—45．307)、慢性胃病史(OR=3．015，95％CI=1．021-8．904)和家族肿瘤史(OR=5．354，95％CI=1．506-19．036)关系密切。结论 多吃新鲜蔬菜水果，少吃盐腌食物，积极治疗慢性胃病可减少胃癌的发病。     

胃癌病例对照研究

目的了解胃癌与其危险因素的关系。方法对洛阳市2003～2004年新发胃癌病人153例，按性别、年龄、民族、居住地为配比条件选取该市健康人153名进行1：1配对的病例对照研究，资料处理采用条件Logistic回归分析。结果吸烟OR 3.85，OR 95％CI2.73～6．98，饮酒OR 2．14，OR 95％CI 1．42～3．21，烟熏食品OR 4．92．OR95％CI 2．63～7．32，父母患瘤OR7.59，OR 95％CI 3．21～26．53。结论经常吸烟、饮酒、食用烟熏食品及其父母患肿瘤可能是胃癌的危险因素。     

吸烟对不同收入人群慢性病患病的影响

目的探讨吸烟对不同经济状况人群的健康影响。方法采用多阶段分层整群随机抽样的方法，在全国共抽取95个县、950个村(居委会)，每个样本村(居委会)随机抽取60户家庭，全国共抽取55200户家庭中15～65岁男性5．93万人。结果研究发现在控制年龄、经济状况、文化程度、就业状况、工作岗位的情况下，不论农村、城镇，与从不吸烟的人相比，有吸烟史的人群慢性病患病率均高(农村OR=1．185，95％CI：1．121～1．253；城镇OR=1．083，95％CI：1．010～1．161)；吸烟对农村男性患慢性病的影响(戒烟OR=2．764，95％CI：2．471～3．092)要大于城镇的相应人群(戒烟OR=2．112，95％CI：1．844～2．419)；另外发现吸烟对低收入人口患慢性病的影响(城镇OR=2．076，95％CI：1．551～2．780；农村OR=2．903，95％CI：2．248～3．749)大于对高收入人口的影响(城镇OR=1．785，95％CI：1．285～2．479；农村OR=2．466，95％CI：1．941～3．134)。结论吸烟对收入低下的人群健康损害更大，应该引起重视。     

胃腺癌危险因素的病例对照研究

目的 探讨与胃癌有关的危险因素。方法 对天津市区1998－1999年的189例新发胃癌病人进行1：1配对病例对照研究,采用条件Logistic回归分析。结果 烟熏食品OR＝2．34,OR95％CI＝1．60－4．98;吸烟量OR＝6．07,OR95％CI＝1．26－7．16;喜食重盐饮食OR＝1．95,OR95％CI＝1．27－3．23;过量摄入动物肉类OR＝1．46,OR95％CI＝1．05－2．02。结论 经常食用烟熏食品、吸烟量大、重盐饮食、过量摄入动物肉类等可能是胃癌的危险因素。     

杭州市城区初中生蔬菜水果摄入情况及影响因素分析

目的 了解杭州市城区初中生蔬菜水果摄入情况及影响因素.方法 在杭州市3个城区初中生中开展横断面自填问卷调查,了解学生每周蔬菜水果的摄入频率、摄入量及相关社会人口学特征,采用logistic多因素回归法分析影响每周吃蔬菜≥21份和水果≥14份的因素.结果 纳入分析的3724名初中生每周每日食蔬菜水果为54.7％,每周进食蔬菜≥21份和水果≥14份(相当于每日食蔬菜≥3份和水果≥2份)为23.6％.女生、母亲文化程度较高、家庭社会经济水平较高的初中生每周蔬菜水果摄入频率和摄入量均较高(P＜0.05).控制了5种社会人口学因素后,每日体力活动≥60 min(OR=1.667,95％CI:1.216 ～ 2.203)、家人每日鼓励多进食蔬菜水果(OR=1.881,95％CI:1.498 ～ 2.363)、每日表扬食蔬菜水果(OR=1.275,95％CI:1.025 ～ 1.586)、每周3 ～6 d(OR=1.691,95％CI:1.310～2.183)和每日(OR=2.944,95％CI:2.348～ 3.690)准备好蔬菜水果、每周3 ～6 d(OR=1.392,95％CI:1.056 ～ 1.835)和每日(OR=2.817,95％CI:2.217～3.580)一起进食蔬菜水果、早餐通常自家做(OR=1.364,95％CI:1.158～1.607)、蔬菜水果健康益处的课程教育(OR=1.238,95％ CI:1.035 ～ 1.480)和认知(OR=3.150,95％CI:1.121 ～ 8.856)与初中生每周食蔬菜≥21份和水果≥14份均有正性关联.结论 杭州市城区初中生蔬菜水果的摄入水平与社会人口学特征、体力活动、家庭饮食环境、蔬菜水果健康益处的教育和认知程度有关.     

胃癌危险因素的病例对照研究

目的 探讨各危险因素与胃癌的关系,方法 对天津市市内区1998年91例新发胃癌病人进行了1：1配对病例对照研究,资料处理采用条件Logistic回归分析,结果 烟熏食品OR＝4．88,OR95％／CI 2．54－9．38,吸烟量OR．6．12,OR95％CI 1．63－22．95,喜食重盐饮食OR．2．87,OR95％CI 1．80－4．58,过量摄入动物肉类OR＝1．71,OR95％CI 1．33－2．19。结论 经常食用烟熏食品,吸烟量大,喜吃重盐饮食,过量摄入动物肉类等可能是胃癌的危险因素。     

亚甲基四氢叶酸还原酶基因1298A→C多态与食管癌易感性关系的病例对照研究

目的 研究亚甲基四氢叶酸还原酶(MTHFR)基因1298A→C多态及其和生活习惯相互作用与食管癌易感性的关系。方法 在食管癌高发区的淮安市楚州区开展了一项病例对照研究(食管癌患者141例,人群对照228名),调查研究对象的生活习惯,采用聚合酶链反应-限制性片段长度多态性技术检测研究对象的MTHFR 1298A→C基因型。结果 ①食管癌组中MTHFR 1298 AA、AC和CC基因型携带者的比例分别为63.8％、34.0％和2.1％,与对照组的71.9％、28.1％和0.0％相比,差异有统计学意义(X_(MH)~2=6.69,P=0.035)。②在MTHFR 1298C等位基因携带者中,伴有吸烟习惯者发生食管癌的调整OR为3.48(95％CI:1.57～7.71),伴有经常饮酒的习惯者发生食管癌的调整OR为2.91(95％CI:1.20～7.08),无饮茶习惯者发生食管癌的调整OR为3.52(95％CI:1.64～7.54)。MTHFR 1298AC和CC基因型与吸烟、饮酒和不饮茶在食管癌发生中的相互作用系数r分别为3.05、3.69和6.30。结论 MTHFR 1298AC和CC基因型对吸烟、饮酒和不饮茶增加食管癌发生风险的作用有明显的放大效应。     

秦皇岛市海港区18岁以上流动人群高血压病流行病学调查

目的了解秦皇岛市海港区18岁以上流动人群中高血压病的流行病学特征,以及吸烟、饮酒、饮食等相关行为危险因素在该人群中的分布情况。方法采取按行业分层、多阶段整群抽样的方法,集中和入户相结合的调查方式获得研究资料,用SPSS 16.0统计软件进行分析。结果此次调查海港区18岁及以上流动人口300人;高血压病患病人数为81人,患病比为27.00%(81/300),吸烟比62.33%(187/300),饮酒比66.33%(199/300),水果摄入不足比81.00%(243/300),蔬菜摄入不足比42.33%(127/300),肉类过量摄入比83.67%(251/300),食用油过量摄入比83.00%(249/300),食盐过量摄入比87.67%(263/300),身体活动低水平比53.00%(159/300),肥胖比33.67%(101/300),超重比36.67%(110/300)。不同年龄组高血压病患病率差异则有统计学意义(χ2=21.28,P0.05),表现为随着年龄增加高血压病患病率呈逐渐上升的趋势。饮酒、吸烟、是否食用新鲜蔬菜、是否过量摄入食用油、是否过量摄入食盐、身体活动状况及超重肥胖均与高血压病相关;年龄(OR=1.166)、饮酒(OR=2.134)、蔬菜摄入相对不足(OR=1.426)、摄入过量盐(OR=1.600)以及超重/肥胖(OR=1.457)等是引起高血压病的行为危险因素。结论经过流行病学调查分析发现该人群中高血压病的患病率较高,相关工作部门应加强健康教育干预措施,加大宣传力度,改变高血压病相关危险行为,逐步降低高血压病发病率。     

Plasma total homocysteine, pregnancy complications, and adverse pregnancy outcomes: the Hordaland Homocysteine study

BACKGROUND: Total homocysteine (tHcy) measured in serum or plasma is a marker of folate status and a risk factor for cardiovascular disease. OBJECTIVE: Our objective was to investigate associations between tHcy and complications and adverse outcomes of pregnancy. DESIGN: Plasma tHcy values measured in 1992-1993 in 5883 women aged 40-42 y were compared with outcomes and complications of 14492 pregnancies in the same women that were reported to the Medical Birth Registry of Norway from 1967 to 1996. RESULTS: When we compared the upper with the lower quartile of plasma tHcy, the adjusted risk for preeclampsia was 32% higher [odds ratio (OR): 1. 32; 95% CI: 0.98, 1.77; P for trend = 0.02], that for prematurity was 38% higher (OR: 1.38; 95% CI: 1.09, 1.75; P for trend = 0.005), and that for very low birth weight was 101% higher (OR: 2.01; 95% CI: 1.23, 3.27; P for trend = 0.003). These associations were stronger during the years closest to the tHcy determination (1980-1996), when there was also a significant relation between tHcy concentration and stillbirth (OR: 2.03; 95% CI: 0.98, 4.21; P for trend = 0.02). Neural tube defects and clubfoot had significant associations with plasma tHcy. Placental abruption had no relation with tHcy quartile, but the adjusted OR when tHcy concentrations >15 micromol/L were compared with lower values was 3.13 (95% CI: 1.63, 6. 03; P = 0.001). CONCLUSION: Elevated tHcy concentration is associated with common pregnancy complications and adverse pregnancy outcomes.     

Dietary predictors of plasma total homocysteine in the Hordaland Homocysteine Study

Established dietary predictors of plasma total homocysteine (tHcy) include folate, riboflavin, and vitamins B6 and B12, while information is scarce regarding other dietary components. The aim of this study was to examine the relation between a variety of food groups, food items and nutrients, and plasma tHcy in a large population-based study. The study population included 5812 men and women aged 47-49 and 71-74 years who completed a 169-item FFQ. tHcy was examined across quartiles of dietary components by multiple linear regression analyses adjusting for age, sex, energy intake, various risk factors for elevated tHcy, as well as for dietary and plasma B-vitamins. Among 4578 non-users of vitamin supplements, intake of vegetables, fruits, cereals, eggs, fish and milk, as well as chicken and non-processed meats were inversely associated with tHcy level. The estimated mean difference in tHcy per increasing quartile of intake ranged from - 0.11 (95 % CI - 0.21, - 0.01) micromol/l for milk to - 0.32 (95 % CI - 0.42, - 0.22) micromol/l for vegetables. Positive associations were found for sweets and cakes. Whole-grain bread was significantly inversely related to tHcy only after additional adjustment for dietary and plasma B-vitamins. The nutrients folate, vitamin B6, B12, and riboflavin were inversely related to tHcy. Complex carbohydrates were inversely, and fat positively associated with tHcy, also after adjustment for dietary and plasma B-vitamins. In conclusion, food items rich in B-vitamins and with a low content of fat and sugar were related to lower tHcy levels. Eggs, chicken, non-processed meat, fish and milk were inversely associated with tHcy.     

Vitamin C and the risk of preeclampsia--results from dietary questionnaire and plasma assay

BACKGROUND: Oxidative stress plays an important role in the pathophysiology of preeclampsia. METHODS: In a case-control study of 109 women with preeclampsia and 259 controls, maternal dietary and plasma vitamin C in relation to preeclampsia risk were assessed. Dietary intake during the periconceptional period and pregnancy was ascertained using a semiquantitative food frequency questionnaire. Logistic regression procedures were used to derive odds ratios (OR) and 95% confidence intervals (CI). Plasma ascorbic acid was determined using automated enzymatic procedures. RESULTS: After adjusting for maternal age, parity, prepregnancy body mass index, and energy intake, women who consumed <85 mg of vitamin C daily (below the recommended dietary allowance), as compared with others, experienced a doubling in preeclampsia risk (OR = 2.1; 95% CI = 1.1-3.9). The OR for extreme quartiles of plasma ascorbic acid (<42.5 vs > or = 63.3 micromol/liter) was 2.3 (95% CI = 1.1-4.6). Compared with women in the highest quartile, those with plasma ascorbic acid <34.6 micromol/liter (lowest decile) experienced a 3.8-fold increased risk of preeclampsia (95% CI = 1.7-8.8). CONCLUSIONS: Our results, if confirmed, would suggest that current public health efforts to increase intake of fruits and vegetables rich in vitamin C and other antioxidants may reduce the risk of preeclampsia.     

Raw and cooked vegetables, fruits, selected micronutrients, and breast cancer risk: a case-control study in Germany

In 1998-2000, a case-control study of breast cancer was conducted in Heidelberg, Germany. Three hundred ten consecutively recruited cases with primary breast cancer were matched according to 10-yr age groups to 353 controls with conditions unrelated to diet or endocrine disorders. Intake of raw vegetables, total vegetables, and whole-grain products was inversely associated with breast cancer risk (highest vs. lowest quartile adjusted odds ratio [OR] 0.51, 95% confidence interval [CI] 0.31-0.84; OR = 0.62, 95% CI = 0.38-1.02; and OR = 0.57; 95% CI = 0.34-0.95, respectively). Also, high intake of some selected vitamins and minerals possessing putative DNA-stabilizing properties displayed significant inverse risk associations. Adjusted ORs were as follows: vitamin C (OR = 0.49, 95% CI = 0.2-0.88), folate equivalents (OR = 0.47, 95% CI = 0.25-0.88), b-carotene (OR = 0.46, 95% CI = 0.27-0.80), zinc (OR = 0.35, 95% CI = 0.15-0.78), and copper (OR = 0.51, 95% CI = 0.31-1.03). In contrast, no significant association with risk was seen for an increased intake of fruits, cooked vegetables, fiber, calcium, manganese, or iron. In this population of German women, components of raw vegetables and some micronutrients appear to decrease breast cancer risk.     

Effect of increased vegetable and fruit consumption on plasma folate and homocysteine concentrations

OBJECTIVE: We assessed the effects of an intervention aimed at increasing the consumption of fruits and vegetables on plasma folate and homocysteine concentrations. METHODS: Seventy-one healthy non-smoking women (mean +/- SD 41 +/- 4 y of age) were randomized to an intervention or a control group. Participants in the intervention group (n = 36) received weekly packets containing fruits and vegetables free of charge and were asked to consume a daily amount of >or=200 g of vegetables and two pieces of fruit (the Dutch recommended intake level) over a period of 1 mo. Control subjects did not receive any intervention. RESULTS: Compared with the control group, reported fruit and vegetable intakes in the intervention group increased by 133 g/d (95% confidence interval [CI] 87-179, P < 0.001) for fruits and juice and 64 g/d (95% CI 37-91, P < 0.001) for vegetables and estimated folate intake from fruits and vegetables increased by 40 microg/d (95% CI 22-58, P < 0.001). However, no effect was observed on plasma folate concentrations (intervention effect 0.3 nmol/L, 95% CI -1.8 to 2.8, P = 0.77) or homocysteine concentrations (intervention effect 0.26 micromol/L, 95% CI -0.34 to 0.87, P = 0.39). CONCLUSION: The results suggest that 4 wk of increased fruit and vegetable consumption to the recommended amounts may be insufficient to change plasma folate and homocysteine concentrations.     

Plasma C-reactive protein and homocysteine concentrations are related to frequent fruit and vegetable intake in Hispanic and non-Hispanic white elders

Elevated C-reactive protein (CRP) and plasma total homocysteine (Hcy) were recently identified as risk factors for cardiovascular disease. However, few studies have related fruit and vegetable consumption to these markers of inflammation and B vitamin deficiency, particularly in the Hispanic population. We examined the relation of fruit and vegetable intake with plasma CRP and Hcy concentrations in a cross-sectional study. Subjects were 445 Hispanic elders and 154 neighborhood-based non-Hispanic white elders living in Massachusetts. Diet was assessed with a FFQ designed for this population. There were significant inverse dose-response associations between fruit and vegetable intake and plasma CRP (P for trend = 0.010) and Hcy (P for trend = 0.033) concentrations, after adjustment for potential confounders. The prevalence of high plasma CRP (> 10 mg/L), and high Hcy (>10.4 micromol/L for women and >11.4 micromol/L for men), was significantly greater among subjects in the lowest quartile of fruit and vegetable consumption relative to those in the highest quartile, 17.9 vs. 9.1% and 58.7 vs. 44.4%, respectively. With each additional serving of fruit and vegetable intake, adjusted odd ratios for high plasma CRP and Hcy were 0.79 (95% CI: 0.65 to 0.97) and 0.83 (95% CI: 0.72 to 0.96), respectively. Greater frequency of fruit and vegetable intake was associated with significantly lower plasma CRP and Hcy concentrations. Because both of these metabolites are known risk factors for CVD, these findings contribute to the evidence that a higher intake of fruit and vegetables may reduce the risk of CVD.     

Distribution and correlates of elevated total homocyst(e)ine: the Stroke Prevention in Young Women Study

PURPOSE: To determine the distribution and correlates of elevated total homocyst(e)ine (tHcy) concentration in a population of premenopausal black and white women. METHODS: Data from the Stroke Prevention in Young Women Study (N = 304), a population-based study of risk factors for stroke in women aged 15-44 years of age, were used to determine the distribution and correlates of elevated tHcy in black (N = 103) and white women (N = 201). RESULTS: The mean tHcy level for the population was 6.58 micromol/L (range 2.89-26.5 micromol/L). Mean tHcy levels increased with age, cholesterol level, alcohol intake, and number of cigarettes smoked (all: p < 0.05). There were no race differences (mean tHcy 6.72 micromol/L among blacks and 6.51 micromol/L among whites; p = 0.4346). Regular use of multivitamins and increasing education was associated with significant reductions in tHcy concentration. Approximately 13% of the sample had elevated tHcy levels, defined as a tHcy concentration > or = 10.0 micromol/L. Multivariate-adjusted correlates of elevated tHcy included education > 12 vs. < or = 12 (odds ratio [OR] = 0.4, 95% confidence interval [CI] = 0.2-0.8); smoking > or = 20 cigarettes/day vs. nonsmokers (OR = 2.8, 95% CI = 1.1-7.3); and the regular use of multivitamins (OR = 0.4, 95% CI = 0.2-0.9). CONCLUSIONS: These results suggest that a substantial proportion of healthy young premenopausal women have tHcy levels that increase their risk for vascular disease. A number of potentially modifiable behavioral and environmental factors appear to be significantly related to elevated tHcy levels in young women.     

Folate intake, serum homocysteine and methylenetetrahydrofolate reductase (MTHFR) C677T genotype are not associated with oral cancer risk in Puerto Rico

We examined the relationships between folate and methionine intake, serum homocysteine levels (as a biomarker for folate metabolism), and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism genotype and risk of oral cancer in a population-based, case-control study in Puerto Rico. Structured questionnaires were used to collect information on demographic factors, usual adult diet, and tobacco and alcohol use. Oral epithelial cells and blood samples were collected from a subset of subjects. Analyses were conducted by logistic regression, adjusting for age, sex, lifetime smoking and lifetime alcohol intake, with the following numbers of cases/controls, respectively: dietary data (341/521); MTHFR genotype (148/149); and homocysteine (60/90). Although increased folate intake was associated with decreased oral cancer risk [adjusted odds ratio (OR) in highest vs. lowest quartile = 0.6, 95% confidence interval (CI): 0.4, 1.0, P(trend) = 0.05)], this finding was due almost entirely to folate intake from fruit (adjusted OR = 0.4, 95% CI: 0.2, 0.6; P(trend) = 0.0001), whereas other dietary folate sources showed no clear association. Methionine intake and serum homocysteine levels were not associated with oral cancer risk. Subjects with the MTHFR C677T homozygous variant (TT) genotype had a nonsignificantly lower risk, and risk patterns tended to differ by level of folate, methionine, alcohol intake and smoking, although the power to detect significant associations in subgroups of these variables was low. Risks for oral cancer are not folate specific; preventive recommendations for this disease should emphasize the importance of a healthy diet, including substantial intake of fruits.     

Choline supplemented as phosphatidylcholine decreases fasting and postmethionine-loading plasma homocysteine concentrations in healthy men

BACKGROUND: A high homocysteine concentration is a potential risk factor for cardiovascular disease that can be reduced through betaine supplementation. Choline is the precursor for betaine, but the effects of choline supplementation on plasma total homocysteine (tHcy) concentrations in healthy humans are unknown. OBJECTIVE: The objective was to investigate whether supplementation with phosphatidylcholine, the form in which choline occurs in foods, reduces fasting and postmethionine-loading concentrations of plasma tHcy in healthy men with mildly elevated plasma tHcy concentrations. DESIGN: In a crossover study, 26 men ingested approximately 2.6 g choline/d (as phosphatidylcholine) or a placebo oil mixture for 2 wk in random order. Fatty acid composition and fat content were similar for both treatments. A methionine-loading test was performed on the first and last days of each supplementation period. RESULTS: Phosphatidylcholine supplementation for 2 wk decreased mean fasting plasma tHcy by 18% (-3.0 micromol/L; 95% CI: -3.9, -2.1 micromol/L). On the first day of supplementation, a single dose of phosphatidylcholine containing 1.5 g choline reduced the postmethionine-loading increase in tHcy by 15% (-4.8 micromol/L; 95% CI: -6.8, -2.8 micromol/L). Phosphatidylcholine supplementation for 2 wk reduced the postmethionine-loading increase in tHcy by 29% (-9.2 micromol/L; 95% CI: -11.3, -7.2 micromol/L). All changes were relative to placebo. CONCLUSIONS: A high daily dose of choline, supplemented as phosphatidylcholine, lowers fasting as well as postmethionine-loading plasma tHcy concentrations in healthy men with mildly elevated tHcy concentrations. If high homocysteine concentrations indeed cause cardiovascular disease, choline intake may reduce cardiovascular disease risk in humans.     

High prevalence of hyperhomocysteinemia in Chinese adults is associated with low folate, vitamin B-12, and vitamin B-6 status

Elevated plasma total homocysteine (tHcy) concentrations are associated with lower folate, vitamin B-12, and vitamin B-6 status and are considered an independent risk factor for cardiovascular disease in developed countries, but data in developing countries are limited. We conducted a cross-sectional study to explore tHcy status and its association with plasma B vitamin status in 2471 Chinese men and women aged 35 to 64 y, living in the urban and rural areas of the northern and the southern regions of China. Blood samples were also collected in 2 seasons (spring and fall). The geometric mean plasma tHcy concentration was significantly higher in the north (adjusted geometric mean, 95% CI; 13.0 micromol/L, 12.6-13.3) than in the south (9.1, 8.9-9.4) after controlling for gender, area (urban and rural), age, and season (spring and fall). Twenty-eight percent of northerners and 7% of southerners had plasma tHcy concentrations>or=16.0 micromol/L, a level used to define hyperhomocysteinemia. Within each region, men had higher plasma tHcy concentrations than women (16.1 vs. 10.6 micromol/L in the north, and 10.7 vs. 7.9 micromol/L in the south) and 40% of the northern men had hyperhomocysteinemia. Generally, individuals living in the urban areas had 30% (95% CI, 1.0-1.6) greater odds of having high tHcy levels (>or=16 micromol/L) than those living in the rural areas. Low plasma concentrations of folate, vitamins B-12 and B-6, older age, being male, and living in urban areas were all independently associated with elevated tHcy, with low folate as the strongest determinant.