Plasma C-reactive protein concentration is not affected by isocaloric dietary fat reduction

OBJECTIVE: There is a strong correlation between plasma C-reactive protein (CRP) concentration and risk of cardiovascular death. Low-fat diets have been recommended for maintenance of cardiovascular health, and it is known that a low-fat diet associated with weight loss lowers CRP concentration. However, it remains unclear whether dietary fat has an effect independent from weight change on markers of inflammation. METHODS: Sixteen overweight subjects who were 46 +/- 14 y old were placed on a weight-maintaining baseline diet consisting of 35% fat, 45% carbohydrate, and 20% energy as protein. After 2 wk, subjects were switched to an isocaloric low-fat diet consisting of 15% fat, 65% carbohydrate, and 20% protein for another 2 wk. For the final 12 wk of the study, subjects consumed the same 15% fat diet ad libitum. At the end of each diet phase, CRP was measured by a high-sensitivity CRP assay. RESULTS: The weight of subjects remained stable during the first 4 wk of isocaloric diets. Plasma CRP concentrations after 2 wk on the weight-maintaining 35% fat diet and 2 wk on the isocaloric 15% fat diet were not significantly different (median +/- interquartile range 1.42 +/- 3.30 and 1.59 +/- 3.29 mg/L, respectively). Three months of ad libitum low-fat diet consumption resulted in a 4.1 +/- 0.7 kg weight loss associated with a decrease in CRP concentration to 1.17 +/- 2.03 mg/L (P = 0.03). CONCLUSION: Loss of body weight decreases CRP concentration, but a decrease in dietary fat without a concurrent change in body weight does not affect CRP concentration in overweight healthy subjects.     

Plasma homocysteine concentration in a Belgian school-age population

BACKGROUND: Total plasma homocysteine (tHcy) is an independent risk factor for cardiovascular disease in adults. Data for children and adolescents are lacking. OBJECTIVE: The aim of this study was to provide a reference range for tHcy and to explore the relation between tHcy and nutritional indexes in a Belgian pediatric population. DESIGN: tHcy, folate, and vitamin B-12 were measured in 647 healthy children (353 girls and 294 boys) aged 5-19 y. RESULTS: The tHcy distribution was, as in adults, skewed to the right [geometric mean (-1 SD, +1 SD): 7.41 micromol/L (5.51, 9.96)]. Concentrations were lowest in younger children and increased with age. After the tHcy distribution was examined according to age, 3 age ranges were distinguished: 5-9 y [6.21 micromol/L (5.14, 7.50)], 10-14 y [7.09 micromol/L (5.69, 8.84)], and 15-19 y [8.84 micromol/L (6.36, 12.29)]. We observed no significant differences in tHcy values between girls and boys in children aged < 15 y; in postpubertal children, however, concentrations were higher in boys than in girls. In the 3 age groups, folate was inversely correlated with tHcy; the negative relation between tHcy and vitamin B-12 was less strong. Familial cardiovascular disease was more frequent in children who had hyperhomocysteinemia. CONCLUSIONS: These observations suggest that in children, as in adults, genetic, nutritional, and endocrine factors are determinants of the metabolism of homocysteine. The significance of tHcy values in childhood and young adulthood in terms of predicting cardiovascular risk in adulthood should be investigated.     

Plasma lyso-phosphatidylcholine concentration is decreased in cancer patients with weight loss and activated inflammatory status

Background  

It has been observed that ras-transformed cell lines in culture have a higher phosphatidylcholine (PC) biosynthesis rate as well as higher PC-degradation rate (increased PC-turnover) than normal cells. In correspondence to these findings, the concentrations of the PC-degradation product lyso-phosphatidylcholine (LPC) in cancer patients were found to be decreased. Our objective was the systematic investigation of the relationship between LPC and inflammatory and nutritional parameters in cancer patients. Therefore, plasma LPC concentrations were assessed in 59 cancer patients and related to nutritional and inflammatory parameters. To determine LPC in blood plasma we developed and validated a HPTLC method.     

Plasma S-adenosylhomocysteine is a better biomarker of atherosclerosis than homocysteine in apolipoprotein E-deficient mice fed high dietary methionine

Homocysteine (Hcy) and S-adenosylhomocysteine (AdoHcy) are critical intermediates of methionine metabolism. To investigate which, if either, of these compounds is more closely related to atherosclerosis, we fed 5 groups of apolipoprotein E (apoE)-deficient mice different diets for 8 wk to induce changes in their plasma Hcy and AdoHcy concentrations. These included an AIN-93G control diet (C), this C diet supplemented with methionine (M), the M diet deficient in folates, vitamin B-6, and vitamin B-12 (M-V), this M diet supplemented with these B vitamins (M+V), and a C diet deficient in B vitamins (C-V). Compared with controls, mice fed the C-V diet had a moderate elevation in their plasma total Hcy (tHcy) levels; however, their plasma AdoHcy concentration and atherosclerotic lesion areas were not different. In contrast, the mice fed the M+V diet had larger atherosclerotic lesion areas and elevated plasma AdoHcy concentrations but their plasma tHcy concentration did not differ from that of the group C mice. The plasma AdoHcy concentration and aortic sinus lesion areas were positively correlated (r = 0.866; P < 0.001). We observed a negative correlation between the plasma AdoHcy concentration and both the DNA methyltransferase activity (r = -0.792; P < 0.001) and global DNA methylation status (r = -0.824; P < 0.001) in the aortic tissue. Hence, our study suggests that plasma AdoHcy is a better biomarker of atherosclerosis than Hcy and may accelerate the development of atherosclerotic lesions in apoE-deficient mice that have been fed a high methionine diet. The mechanisms underlying this effect may be related to the AdoHcy-mediated inhibition of DNA methylation in the aortic tissue.     

小麦面筋蛋白降低血浆同型半胱氨酸水平的研究

目的探讨不同水平下的酪蛋白和小麦面筋蛋白对血浆同型半胱氨酸(Hcy)水平的影响。方法健康Wistar大鼠48只随机分为6组,分别为12.5%、25%、50%酪蛋白组和14.5%、29%、58%小麦面筋蛋白组。大鼠自由进食、饮水,每天称重并记录大鼠进食量。喂养实验饲料14天后处死,采集血液,取肝脏组织,用于测定血浆和肝脏中Hcy、半胱氨酸(Cys)等氨基酸指标以及同型半胱氨酸甜菜碱甲基转移酶(BHMT)和胱硫醚β-合成酶(CBS)等酶学指标。结果小麦面筋蛋白组的大鼠体重增长显著低于酪蛋白组,而在小麦面筋蛋白组随着蛋白含量的提高,大鼠的饲料摄入量明显逐渐减少。小麦面筋蛋白的摄入使血浆Hcy浓度显著低于酪蛋白组,相反血浆Cys的浓度,小麦蛋白组明显高于酪蛋白组。结论小麦面筋蛋白对血浆Hcy水平的影响主要取决于高Cys与低蛋氨酸含量,但是其赖氨酸和苏氨酸含量较低也是不能忽视的影响因素之一。其主要的作用机制是Cys的升高促进了Hcy代谢的酶活性,增加了Hcy的代谢消耗。     

The carbonyl content of specific plasma proteins is decreased by dietary copper deficiency in rats

Copper (Cu) deficiency is associated with increased susceptibility of tissue homogenates or lipoproteins to oxidation in vitro. Plasma is easily sampled and contains both lipid and protein components that may be susceptible to oxidation, making it appropriate to investigate plasma oxidation variables as biomarkers of in vivo oxidative stress. Oxidation of plasma proteins may be discernible as an increased content of carbonyl (aldehyde or ketone) groups on the proteins. Weanling male Long-Evans rats were fed sucrose-based modified AIN-93G diets with (+Cu, 6.2 mg Cu/kg diet) or without (-Cu, 0.4 mg/kg) added Cu for 4 wk before killing. Plasma and RBC Cu,Zn-superoxide dismutase activities and liver Cu concentration were significantly decreased and relative heart weight was significantly increased, confirming the Cu-deficient status of the -Cu rats. Dinitrophenylhydrazine (DNP) derivatization followed by SDS-PAGE and Western blotting using commercial anti-DNP antibody demonstrated that several plasma proteins in +Cu control rats showed evidence of carbonyl groups. The carbonyl content of these bands was lower in -Cu rats, not greater as would have been expected with oxidative damage to these proteins. Although dietary Cu deficiency may increase susceptibility to oxidative stress, it does not lead to accumulation of oxidized plasma proteins in this animal model.     

Secretion of alpha-tocopherol in VLDL is decreased by dietary protein insufficiency in young growing rats

The concentrations of alpha-tocopherol in plasma and most peripheral tissues were shown previously to be low in young growing rats fed a low protein diet. To examine the secretion rates of VLDL alpha-tocopherol and triglycerides, and lipoprotein lipase activity, weanling rats were fed a low protein (LP, 8 g/100 g lactalbumin) or a normal protein (NP, 20 g/100 g lactalbumin) diet for 6 wk. The absolute secretion rate of VLDL triglyceride (micromol/h) of the LP group was not significantly different from that of the NP group (P: > 0.05), but was significantly higher (P: < 0.05) when expressed relative to body weight [micromol/(h. kg)]. The secretion rates of VLDL alpha-tocopherol were significantly lower (P: < 0.05) in the LP group than in the NP group. The activities of hepatic lipase, lipoprotein lipase and total heparin-releasable lipase in plasma of the LP group were only 50-60% those of the NP group (P: < 0.05). The results demonstrated that the secretion rate of VLDL alpha-tocopherol and activities of lipases in postheparin plasma were significantly lower in rats fed a low protein diet. Thus, the redistribution of alpha-tocopherol from liver to peripheral tissues appears to have been impaired by dietary protein insufficiency.     

Fluctuations in dietary methionine intake do not alter plasma homocysteine concentration in healthy men

A moderate elevation in plasma total homocysteine (tHcy) has been established as an independent risk factor for vascular disease. An important exogenous source of homocysteine is methionine found in foods rich in animal protein. We investigated the response of tHcy to fluctuations in methionine intake in a cross-over intervention trial (two arms). Healthy men (n = 52; 19-29 y) were screened for habitual methionine intake using a food-frequency questionnaire. Subjects in the top quartile for methionine intake (n = 13), with a baseline fasting tHcy of 7.01 +/- 1.84 micromol/L (mean +/- SD), were randomly assigned to receive either a low-methionine intervention diet for 1 wk followed by a control diet for 1 wk or vice-versa. Simultaneously, those in the bottom quartile for methionine intake (n = 11), with a fasting plasma tHcy of 9.79 +/- 7. 20 micromol/L (mean +/- SD), received either a high methionine intervention diet for 1 wk followed by a control diet or vice-versa. All subjects had serum folate, red-cell folate, serum vitamin B-12 and plasma pyridoxal phosphate (PLP) concentrations within normal ranges. During the intervention, subjects in the top quartile for methionine intake reduced their daily methionine intake 79%, from 1969 +/- 639 to 407 +/- 83 mg/d (P: 相似文献   

Plasma total homocysteine is influenced by prandial status in humans: the Hordaland Hhomocysteine Sstudy

Plasma total homocysteine (tHcy) is a risk factor for cardiovascular disease, adverse pregnancy outcomes and impaired cognitive function. No population-based studies on the possible influence of prandial status on tHcy have been published. The aim of this study was to investigate the variation in plasma tHcy levels in relation to time since last meal. A cross-sectional, population-based study including 18,044 individuals in Western Norway was conducted. Most subjects were in the age groups 40-42 and 65-67 y. Participants who had not eaten during the past 6 h before the blood sampling had significantly higher mean tHcy levels compared with those who had eaten; 11.7 [95% confidence interval (CI): 11.4-12.1] vs. 11.2 (95% CI: 11.1-11.3) micromol/L among men (P = 0.03) and 10.2 (95% CI: 9.9-10.6) vs. 9.7 (95% CI: 9.6-9.7) micromol/L among women (P = 0.003). In all groups except older women, tHcy concentrations were generally higher with increasing time after a meal (P-trend <0.01 in all 3 groups). These findings suggest that fasting status and time since last meal may influence levels of tHcy and should be considered in studies of tHcy as a risk factor for cardiovascular and other diseases, and when comparing tHcy values among studies.     

HIV infection is associated with decreased dietary diversity in South African children

Little is known about dietary diversity of children residing in areas of high HIV prevalence. This study examined dietary diversity in 381 children ages 6-24 mo in rural South Africa. Twenty-eight (7.3%) children and 170 mothers (44.6%) were HIV infected. Home visits were conducted weekly and a detailed history of dietary intake obtained. A dietary diversity score was computed based on the weekly consumption of 8 food classes. Low dietary diversity was defined as falling within the lowest quartile of the diversity scale. There were 22,772 child weeks of observation: 1369 for HIV-infected children, 8876 for HIV-uninfected children born to HIV-infected mothers, and 12,527 for HIV-uninfected children born to HIV-uninfected mothers. Low dietary diversity was more common in HIV-infected children [crude odds ratio (OR), 2.59; 95% CI, 1.52 to 4.41) compared with children born to HIV-uninfected mothers. In a multiple logistic regression analysis adjusting for socioeconomic and health status, HIV-infected children had lower dietary diversity (conditional OR, 1.76; 95% CI, 1.06 to 2.94) than HIV-uninfected children. HIV-infected children consumed less in 6 of 8 food classes compared with HIV-uninfected children, with the 2 exceptions being breast milk and formula milk. In rural South Africa, HIV-infected children's diets are significantly less diverse than those of HIV-uninfected children. This may be a factor contributing to increased morbidity and poorer survival in these children.     

Plasma homocysteine concentration in healthy middle-aged men and its presumed association with cardiovascular mortality]

It has recently become clear that hyperhomocysteinemia is an independent risk factor for vascular diseases. The plasma homocysteine concentrations of 71 healthy men (aged 40-49) living in Hungary were compared with those of randomly selected healthy age-matched men (n = 260) living in 11 different countries. The association between the mean plasma homocysteine concentration and reported cardiovascular mortality was analyzed in the respective countries. In Hungary the mean (+/- SD) plasma homocysteine concentration was 10.6 +/- 4.3 mumol/l. In the 11 other countries the mean (+/- SD) plasma homocysteine concentration ranged from 7.1 +/- 1.4 mumol/l (Schleiz, Germany, n = 20) to 10.7 +/- 2.1 mumol/l (Kuopio, Finland, n = 20). There was a significant correlation (r = 0.71, p < 0.005) between the plasma homocysteine concentration and male cardiovascular mortality in there countries. The strength of the correlation between the male plasma homocysteine concentration and cardiovascular mortality suggests that homocysteine may be an important factor in the variation of cardiovascular mortality between populations. The mean plasma homocysteine concentrations were the highest in the Hungarian (Budapest and Pest county) and the Finnish (Kuopio) groups but cardiovascular mortality is higher in Hungary than in Finland, referring to the pivotal role of other cardiovascular risk factors for the Hungarian population.     

VLDL metabolism in rats is affected by the concentration and source of dietary protein

The present study was designed to determine if changes in dietary protein level and source are related to changes in VLDL lipid concentrations and VLDL binding by hepatic membranes and isolated hepatocytes. Male Wistar rats were fed cholesterol-free diets containing 10, 20 or 30 g/100 g casein or highly purified soybean protein for 4 wk. Hepatic, plasma and VLDL lipids, VLDL apo B-100 and VLDL uptake by isolated hepatocytes and VLDL binding to hepatic membrane were determined. Increasing casein or soybean protein level (from 10 to 30 g/100 g) in the diet increased VLDL apo B-100, indicating an increase in the number of VLDL particles. VLDL uptake by isolated hepatocytes and VLDL binding to hepatic membrane increased when the protein level increased from 10 to 20 g/100 g in the diet and decreased with 30 g/100 g protein, regardless of protein type. The dietary protein source did not affect plasma total cholesterol concentrations at any protein level. Feeding 20 g/100 g soybean protein compared with casein lowered plasma triglyceride concentrations and VLDL number as measured by decreased VLDL-protein, -phospholipid, -triglyceride, -cholesterol and -apo B-100. VLDL uptake by isolated hepatocytes and VLDL binding to hepatic membrane were higher in rats fed soybean protein than those fed casein. The higher VLDL uptake could be responsible for the hypotriglyceridemia in rats fed soybean protein.     

Improvements in circulating cholesterol, antioxidants, and homocysteine after dietary intervention in an Australian Aboriginal community

BACKGROUND: Poor nutrition contributes to high rates of coronary heart disease among Australian Aboriginal populations. Since late 1993, the Aboriginal community described here has operated a healthy lifestyle program aimed at reducing the risk of chronic disease. OBJECTIVE: We evaluated the effectiveness of a community-directed intervention program to reduce coronary heart disease risk through dietary modification. DESIGN: Intervention processes included store management policy changes, health promotion activities, and nutrition education aimed at high-risk individuals. Dietary advice was focused on decreasing saturated fat and sugar intake and increasing fruit and vegetable intake. Evaluation of the program included conducting sequential, cross-sectional risk factor surveys at 2-y intervals; measuring fasting cholesterol, lipid-soluble antioxidants, and homocysteine concentrations; and assessing smoking status. Nutrient intakes were estimated from analysis of food turnover in the single community store. RESULTS: There was a significant reduction in the prevalence of hypercholesterolemia (age-adjusted prevalences were 31%, 21%, and 15% at baseline, 2 y, and 4 y, respectively; P < 0.001). There were significant increases in plasma concentrations of alpha-tocopherol, lutein and zeaxanthin, cryptoxanthin, and beta-carotene across the population. Retinol and lycopene concentrations did not change significantly. Mean plasma homocysteine concentrations decreased by 3 micromol/L. There was no significant change in smoking prevalence between the 2 follow-up surveys. There was an increase in the density of fresh fruit and vegetables and carotenoids in the food supply at the community store. CONCLUSION: This community-directed dietary intervention program reduced the prevalence of coronary heart disease risk factors related to diet.     

Plasma homocysteine levels in hyperinsulinemic patients

In order to evaluate the clinical characteristics of metabolic syndrome, a screening procedure was performed and in a cohort of middle-aged (40-60 years) hyperinsulinaemic (fasting plasma insulin > 15 microU/ml) and/or postprandial [120 min after 75 g glucose load] insulin > 45 microU/ml) subjects (n = 91; men/women: 38/53; age mean +/- SD 47.6 +/- 4.3 years; body mass index: 34.6 +/- 4.9 kg/m2; waist-hip ratio: 0.92 +/- 0.07; actual blood pressure 146 +/- 16/87 +/- 9 mmHg; fasting insulin: 24.2 +/- 11.3 microU/ml; postprandial insulin 125.5 +/- 103.8 microU/ml; serum LDL-cholesterol: 3.73 +/- 1.09 mmol/l; HDL-cholesterol: 1.12 +/- 0.30 mmol/l; triglycerides: 2.97 +/- 2.38 mmol/l; uric acid 279 +/- 79 mumol/l) plasma fasting homocysteine, vitamin B12 and folic acid levels were simultaneously determined. The values were separately evaluated according to the stages of glucose tolerance (normal glucose tolerance [n = 47]; impaired glucose tolerance [n = 24] and diabetes mellitus [n = 20]). Laboratory normal values were determined in 47 healthy subjects (control group, age: 45.0 +/- 7.8 years, men/women: 19/28). There was no significant difference between hyperinsulinaemic and control subjects regarding plasma homocysteine (9.28 +/- 3.81 mumol/l vs. 9.63 +/- 2.70 mumol/l), folic acid (8.5 +/- 5.9 ng/ml vs. 7.5 +/- 2.1 ng/ml) and vitamin B12 levels (423 +/- 141 pg/ml vs. 356 +/- 121 pg/ml). Plasma homocysteine levels were significantly (p < 0.001) higher in hyperinsulinaemic men than women (11.34 +/- 4.72 mumol/l [n = 38] vs. 7.86 +/- 2.13 mumol/l [n = 53]). There was no significant difference between subgroups classified according to the stages of glucose tolerance in hyperinsulinaemic groups. Plasma homocysteine values exceeding the upper limit of normal range (> 12.45 mumol/l) were detected at a similar prevalence rate in control (4/47 = 8.5%) and in hyperinsulinaemic subjects (10/91 = 10.9%). A weak but statistically significant correlation was found between plasma homocysteine values and age of subjects (r = 0.222; p < 0.05) whereas a stronger correlation was documented between plasma homocysteine and serum creatinine values (r = 0.658; p < 0.001) in hyperinsulinaemic groups (n = 91). Plasma homocysteine values independently from the stages of glucose tolerance are not elevated in hyperinsulinaemic subjects. Hyperhomocysteinaemia is not a characteristic feature of hyperinsulinism suggesting that plasma homocysteine levels are of no considerable importance in the complex pathomechanism of atherosclerosis at early stages of metabolic syndrome.     

Plasma S-adenosylhomocysteine is a more sensitive indicator of cardiovascular disease than plasma homocysteine.

BACKGROUND: Although plasma total homocysteine has been identified as an independent risk factor for vascular disease in a multitude of studies, there is a considerable overlap in values between patients at risk and control subjects. The difference in values can be used to distinguish statistically between the 2 groups, provided each group is large enough; however, discriminating between individual patients at risk and control subjects is difficult. OBJECTIVE: We investigated whether the precursor of homocysteine, S-adenosylhomocysteine, is a more sensitive indicator of risk. DESIGN: We measured plasma total homocysteine, S-adenosylhomocysteine, S-adenosylmethionine, creatinine, folate, and vitamin B-12 in 30 patients with proven cardiovascular disease and 29 age- and sex-matched control subjects. RESULTS: The homocysteine values (+/-SD) were 12.8 +/- 4.9 (95% CI: 11.0, 14.7) micromol/L for patients and 11.0 +/- 3.2 (9.8, 12.2) micromol/L for control subjects. The S-adenosylhomocysteine values were 40.0 +/- 20.6 (32.3, 47.7) nmol/L for patients and 27.0 +/- 6.7 (24.5, 30.0) nmol/L for control subjects (P = 0.0021). The S-adenosylmethionine values were 121.8 +/- 42.9 (105.8, 137.8) nmol/L for patients and 103.9 +/- 21.8 (95.6, 112.2) nmol/L for control subjects (P = 0.0493). The creatinine values were 110 +/- 27 (97, 120) micromol/L for patients and 97 +/- 9 (80, 100) micromol/L for control subjects (P = 0.0025). Values for folate and vitamin B-12 did not differ significantly between groups. CONCLUSIONS: Plasma S-adenosylhomocysteine appears to be a much more sensitive indicator of the difference between patients with cardiovascular disease and control subjects than is homocysteine. Both plasma total homocysteine and S-adenosylhomocysteine are significantly correlated with plasma creatinine in patients.     

Bioavailable dietary iron is associated with hemoglobin concentration in Mexican preschool children

The objective of this study was to estimate the amount of bioavailable iron (FeBIO) in the diet of Mexican children aged 12-59 mo through the application of algorithms that use dietary variables and analyze the association between estimated FeBIO and hemoglobin (Hb) concentration. Data were analyzed for 919 children aged 12-59 mo old who participated in a national probabilistic survey on nutrition, in which a 24-h dietary recall was applied and Hb concentration was determined through the use of portable photometers. Dietary intakes were determined for total iron, heme and nonheme iron, vitamin C, phytates, and meat (red meat, poultry, and fish). Using these dietary variables and distinct scenarios on body iron reserves, we used algorithms to estimate the amount of FeBIO in the diet. Linear regression models were adjusted to evaluate the association between FeBIO and Hb. The mean iron intake was 6.2 +/- 4.4 mg/d and the mean estimated FeBIO ranged between 0.14 and 0.37 mg/d depending on different assumptions about iron reserves, representing 2.7-6.1% of total iron intake. The Hb concentration, adjusted for altitude and presence of diarrhea, was positively associated with FeBIO in children 12-23 mo old (P < 0.05) but not in children 24-59 mo old. The estimated FeBIO is low in relation to physiological requirements and is compatible with existing high iron deficiency prevalence rates in Mexico. Although Hb is not a specific indicator of iron status, it was significantly associated with FeBIO.     

Dietary antioxidant capacity is associated with improved serum antioxidant status and decreased serum C-reactive protein and plasma homocysteine concentrations

Purpose

To investigate the associations of dietary TAC from diet and supplements with serum antioxidant concentrations and serum C-reactive protein (CRP) and plasma total homocysteine (tHcy) in US adults.

Methods

This was a cross-sectional study. Food consumption data, serum antioxidant levels, and serum CRP and Plasma tHcy concentrations of 4,391 US adults aged ≥19 years in the National Health and Nutrition Examination Survey 2001–2002 were analyzed. The USDA flavonoid and proanthocyanidin databases and dietary supplement data as well as antioxidant capacities of 43 antioxidants were also utilized.

Result

Serum CRP and plasma tHcy concentrations were higher in older adults, smokers, and those with lower non-leisure time physical activity levels (P < 0.05). Energy-adjusted daily total antioxidant capacity (TAC) from diet and supplements was positively associated with serum vitamin E and carotenoid concentrations (P < 0.05). Adjusted odds ratio (OR) for plasma tHcy >13 μmol/L significantly decreased across quartiles of TAC from diet and supplements (Q1 = 2.18 (1.56–2.77); Q2 = 1.30 (1.00–2.07); Q3 = 1.34 (0.84–2.28); Q4 = 1.00; P for linear trend <0.001). A negative trend across quartiles of TAC from diet and supplements was also observed in OR for serum CRP ≥3 mg/L (Q1 = 1.26 (0.97–1.70); Q2 = 1.21 (0.91–1.66); Q3 = 0.97 (0.80–1.24); Q4 = 1.00; P for linear trend <0.05).

Conclusions

These findings indicated that dietary TAC provided an integrated conceptual tool in assessing serum antioxidants and investigating the associations between antioxidant intake and CVD risk. The implicated applicability of dietary TAC needs further validation in prospective cohort studies.     

Plasma homocysteine is associated with the risk of mild cognitive impairment in an elderly Korean population

Elderly individuals with mild cognitive impairment (MCI) are at high risk for developing dementia, including Alzheimer's disease. Previous studies have proposed that elevated plasma homocysteine might be a risk factor for dementia. However, the impact of plasma homocysteine on MCI remains controversial. We investigated the relation between hyperhomocysteinemia and the risk of MCI in an elderly Korean population. A total of 1215 elderly subjects (aged 60-85 y) were selected from the Ansan Geriatric study to participate in this study. MCI was diagnosed on the basis of the Mayo Clinic criteria. Mean plasma homocysteine concentrations were higher in elderly subjects with MCI than in normal elderly subjects (17.6 +/- 7.4 vs. 15.7 +/- 4.8 micromol/L; P < 0.001). Subjects with hyperhomocysteinemia (>15 micromol/L) also had a higher prevalence of MCI. The unadjusted OR for MCI was greater in subjects with hyperhomocysteinemia than in normal subjects and it increased according to the degree of hyperhomocysteinemia (OR = 1.39; 95% CI = 1.09-1.79 vs. OR = 2.61; 95% CI = 1.22-5.61). These trends did not differ after adjustment for age, sex, and other putative risk factors for cognitive dysfunction (OR = 1.40; 95% CI = 1.07-1.83 vs. OR = 2.40; 95% CI = 1.08-5.31). In conclusion, hyperhomocysteinemia may be an independent risk factor for MCI in elderly Koreans. A causal relationship between plasma homocysteine levels and cognitive impairment should be evaluated in a follow-up study of elderly Korean subjects.