scholarly journals B vitamins attenuate the epigenetic effects of ambient fine particles in a pilot human intervention trial

2017 ◽  
Vol 114 (13) ◽  
pp. 3503-3508 ◽  
Author(s):  
Jia Zhong ◽  
Oskar Karlsson ◽  
Guan Wang ◽  
Jun Li ◽  
Yichen Guo ◽  
...  

Acute exposure to fine particle (PM2.5) induces DNA methylation changes implicated in inflammation and oxidative stress. We conducted a crossover trial to determine whether B-vitamin supplementation averts such changes. Ten healthy adults blindly received a 2-h, controlled-exposure experiment to sham under placebo, PM2.5 (250 μg/m3) under placebo, and PM2.5 (250 μg/m3) under B-vitamin supplementation (2.5 mg/d folic acid, 50 mg/d vitamin B6, and 1 mg/d vitamin B12), respectively. We profiled epigenome-wide methylation before and after each experiment using the Infinium HumanMethylation450 BeadChip in peripheral CD4+ T-helper cells. PM2.5 induced methylation changes in genes involved in mitochondrial oxidative energy metabolism. B-vitamin supplementation prevented these changes. Likewise, PM2.5 depleted 11.1% [95% confidence interval (CI), 0.4%, 21.7%; P = 0.04] of mitochondrial DNA content compared with sham, and B-vitamin supplementation attenuated the PM2.5 effect by 102% (Pinteraction = 0.01). Our study indicates that individual-level prevention may be used to complement regulations and control potential mechanistic pathways underlying the adverse PM2.5 effects, with possible significant public health benefit in areas with frequent PM2.5 peaks.

1962 ◽  
Vol 42 (2) ◽  
pp. 183-190 ◽  
Author(s):  
B. D. Owen ◽  
A. Reddon ◽  
F. Whiting

Ninety-two sows and two hundred and sixteen pigs were employed in four gestation-lactation and three growing-finishing experiments to determine the adequacy of barley grown on the Grey Wooded soils of the Peace River region in northwestern Canada, as a source of riboflavin, pantothenic and nicotinic acid in swine rations. Vitamin B12 was assessed as a dietary essential in the all-plant rations. In the gestation-lactation experiments sow gains during gestation were greater in the B-vitamin supplemented lot and a trend toward heavier weaning weights of pigs was evident. Vitamin supplementation increased the level of vitamin B12 in sow’s milk collected 1 week post-partum and of both riboflavin and pantothenic acid collected 1 week and 6 weeks post-partum. Nicotinic acid content of sows’ milk was unaffected by supplementation. There was a highly significant decrease in riboflavin level in both control and supplemented lots between 1 and 6 weeks following parturition. The decrease was greatest in the unsupplemented lot.B-vitamin supplementation did not affect growing period gains or pig carcass quality in the growing-finishing experiments. However, certain significant growth responses were noted in the finishing period.The data indicate that the basal rations employed contained adequate riboflavin, pantothenic and nicotinic acid to support normal gestation, lactation and growth in Yorkshire swine.


2004 ◽  
Vol 24 (2) ◽  
pp. 301-307 ◽  
Author(s):  
Pål I. Holm ◽  
Øyvind Bleie ◽  
Per M. Ueland ◽  
Ernst A. Lien ◽  
Helga Refsum ◽  
...  

2008 ◽  
Vol 67 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Robert Clarke

Elevated plasma homocysteine (Hcy) concentrations have been implicated with risk of cognitive impairment and dementia, but it is unclear whether low vitamin B12 or folate status is responsible for cognitive decline. Most studies reporting associations between cognitive function and Hcy or B-vitamins have used a cross-sectional or case–control design and have been unable to exclude the possibility that such associations are a result of the disease rather than being causal. The Hcy hypothesis of dementia has attracted considerable interest, as Hcy can be easily lowered by folic acid and vitamin B12, raising the prospect that B-vitamin supplementation could lower the risk of dementia. While some trials assessing effects on cognitive function have used folic acid alone, vitamin B12 alone or a combination, few trials have included a sufficient number of participants to provide reliable evidence. An individual-patient-data meta-analysis of all randomised trials of the effects on cognitive function and vascular risk of lowering Hcy with B-vitamins will maximise the power to assess the epidemiologically-predicted differences in risk. Among the twelve large randomised Hcy-lowering trials for prevention of vascular disease, data should be available on about 30 000 participants with cognitive function. The principal investigators of such trials have agreed to combine individual-participant data from their trials after their separate publication.


2010 ◽  
Vol 103 (11) ◽  
pp. 1629-1634 ◽  
Author(s):  
Timothy J. Green ◽  
C. Murray Skeaff ◽  
Jennifer A. McMahon ◽  
Bernard J. Venn ◽  
Sheila M. Williams ◽  
...  

Elevated plasma total homocysteine (tHcy) is a risk factor for vascular disease but lowering tHcy with B-vitamins, including folate, has generally not reduced vascular events in secondary prevention trials. Elevated plasmaS-adenosylhomocysteine (AdoHcy) concentration may be a more sensitive indicator of vascular disease than plasma tHcy. However, unlike tHcy, plasma AdoHcy did not correlate with folate concentration in one study indicating that folate supplementation may not lower AdoHcy. Our aim was to determine whether providing B-vitamin supplements to healthy older people with elevated tHcy (>13 μmol/l) affects plasma AdoHcy andS-adenosylmethionine (AdoMet) concentrations. Healthy older participants (n276; ≥ 65 years) were randomised to receive a daily supplement containing folate (1 mg), vitamin B12(500 μg) and vitamin B6(10 mg), or placebo, for 2 years. Of these participants, we selected the first fifty participants in each treatment group and measured plasma AdoHcy and AdoMet. Plasma tHcy was 4·4 (95 % CI 3·2, 5·6;P < 0·001) μmol/l lower at 2 years in the vitamins group compared with the placebo group. At 2 years, there were no significant differences in plasma AdoMet (+4 % (95 % CI − 2, 11);P = 0·19), AdoHcy ( − 1 % (95 % CI − 10, 8);P = 0·61) or the AdoMet:AdoHcy ratio (0·22 (95 % CI − 0·04, 0·49);P = 0·10) between the two groups. In conclusion, B-vitamin supplementation of older people lowered plasma tHcy but had no effect on plasma AdoMet or AdoHcy concentration. If elevated plasma AdoHcy is detrimental, this may explain why B-vitamins have generally failed to reduce vascular events in clinical trials.


2004 ◽  
Vol 92 (11) ◽  
pp. 1086-1091 ◽  
Author(s):  
Anita Peeters ◽  
Els van der Molen ◽  
Henk Blom ◽  
Martin den Heijer

SummaryHyperhomocysteinemia is a risk factor for arterial vascular disease and venous thrombosis. The pathophysiology of this relation is unclear, but several studies suggest that hyperhomocysteinemia impairs endothelial function. We examined the effect of homocysteine lowering by B-vitamin supplementation on tissue plasminogen activator (tPA), plasminogen activator inhibitor type 1 (PAI) and von Willebrand factor (vWf) markers of endothelial dysfunction in hyperhomocysteinemic and normohomocysteinemic volunteers. A total of 123 healthy volunteers were randomized to placebo or B-vitamins (5 mg folic acid, 0.4 mg hydroxycobalamin and 50 mg pyridoxine) daily for 8 weeks. Before and after the intervention period, blood samples were taken for measurements of homocysteine, tPA, PAI and vWf.There was no evident association between homocysteine concentration and concentrations of markers of endothelial dysfunction at baseline.The mean reduction of homocysteine concentration was 31% (95%CI 22.7 to 39.1) in the B-vitamin group compared to 3% reduction in the placebo group. Concentrations of tPA, PAI and vWf did not change after supplementation of B-vitamins. In conclusion, the results of our study show that homocysteine reduction by B-vitamin supplementation has no effect on markers of endothelial dysfunction in healthy volunteers.


2008 ◽  
Vol 78 (2) ◽  
pp. 64-69 ◽  
Author(s):  
Choi ◽  
Cho

This study investigated the effect of vitamin B6 deficiency on the utilization and recuperation of stored fuel in physically trained rats. 48 rats were given either vitamin B6-deficient (B6–) diet or control (B6+) diet for 4 weeks and were trained on treadmill for 30 minutes daily. All animals were then subdivided into 3 groups: before-exercise (BE); during-exercise (DE); after-exercise (AE). The DE group was exercised on treadmill for 1 hour just before being sacrificed. Animals in the AE group were allowed to take a rest for 2 hours after being exercised like the DE group. Glucose and free fatty acids were compared in plasma. Glycogen and triglyceride were compared in liver and skeletal muscle. Protein levels were compared in plasma, liver, and skeletal muscle. Compared with the B6+ group, plasma glucose levels of the B6– group were significantly lower before and after exercise. Muscle glycogen levels of the B6– group were significantly lower than those of the B6+ group regardless of exercise. The liver glycogen level of the B6– group was also significantly lower than that of B6+ group during and after exercise. Before exercise, plasma free fatty acid levels were not significantly different between the B6+ and B6– groups, and plasma free fatty acid levels of the B6– group were significantly lower during and after exercise. The muscle triglyceride level of the B6– group was significantly lower than that of the B6+ group before exercise, and there were no differences between B6+ and B6– groups during and after exercise. Liver triglyceride levels were not significantly different between B6+ and B6– groups. Plasma protein levels of the B6– group were lower than those of B6+ before and after exercise. Muscle protein levels of the B6– group were not significantly different from those of the B6+ group. Liver protein levels of the B6– group were significantly lower than that of the B6+ group after exercise. Liver protein levels of both B6+ and B6– groups were not significantly changed, regardless of exercise. Thus, it is suggested that vitamin B6 deficiency may reduce fuel storage and utilization with exercise in physically trained rats.


2021 ◽  
Vol 13 (1) ◽  
pp. 368
Author(s):  
Dillon T. Fitch ◽  
Hossain Mohiuddin ◽  
Susan L. Handy

One way cities are looking to promote bicycling is by providing publicly or privately operated bike-share services, which enable individuals to rent bicycles for one-way trips. Although many studies have examined the use of bike-share services, little is known about how these services influence individual-level travel behavior more generally. In this study, we examine the behavior of users and non-users of a dockless, electric-assisted bike-share service in the Sacramento region of California. This service, operated by Jump until suspended due to the coronavirus pandemic, was one of the largest of its kind in the U.S., and spanned three California cities: Sacramento, West Sacramento, and Davis. We combine data from a repeat cross-sectional before-and-after survey of residents and a longitudinal panel survey of bike-share users with the goal of examining how the service influenced individual-level bicycling and driving. Results from multilevel regression models suggest that the effect of bike-share on average bicycling and driving at the population level is likely small. However, our results indicate that people who have used-bike share are likely to have increased their bicycling because of bike-share.


2021 ◽  
pp. 003329412110268
Author(s):  
Jaime Ballard ◽  
Adeya Richmond ◽  
Suzanne van den Hoogenhof ◽  
Lynne Borden ◽  
Daniel Francis Perkins

Background Multilevel data can be missing at the individual level or at a nested level, such as family, classroom, or program site. Increased knowledge of higher-level missing data is necessary to develop evaluation design and statistical methods to address it. Methods Participants included 9,514 individuals participating in 47 youth and family programs nationwide who completed multiple self-report measures before and after program participation. Data were marked as missing or not missing at the item, scale, and wave levels for both individuals and program sites. Results Site-level missing data represented a substantial portion of missing data, ranging from 0–46% of missing data at pre-test and 35–71% of missing data at post-test. Youth were the most likely to be missing data, although site-level data did not differ by the age of participants served. In this dataset youth had the most surveys to complete, so their missing data could be due to survey fatigue. Conclusions Much of the missing data for individuals can be explained by the site not administering those questions or scales. These results suggest a need for statistical methods that account for site-level missing data, and for research design methods to reduce the prevalence of site-level missing data or reduce its impact. Researchers can generate buy-in with sites during the community collaboration stage, assessing problematic items for revision or removal and need for ongoing site support, particularly at post-test. We recommend that researchers conducting multilevel data report the amount and mechanism of missing data at each level.


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