B-Vitamins and Bone Health–A Review of the Current Evidence

Because of ongoing global ageing, there is a rapid worldwide increase in incidence of osteoporotic fractures and the resultant morbidity and mortality associated with these fractures are expected to create a substantial economic burden. Dietary modification is one effective approach for prevention of osteoporosis in the general population. Recently, B vitamins have been investigated for their possible roles in bone health in human studies. In this review, we provide different lines of evidence and potential mechanisms of individual B vitamin in influencing bone structure, bone quality, bone mass and fracture risk from published peer-reviewed articles. These data support a possible protective role of B vitamins, particularly, B2, B6, folate and B12, in bone health. However, results from the clinical trials have not been promising in supporting the efficacy of B vitamin supplementation in fracture reduction. Future research should continue to investigate the underlying mechanistic pathways and consider interventional studies using dietary regimens with vitamin B enriched foods to avoid potential adverse effects of high-dose vitamin B supplementation. In addition, observational and interventional studies conducted in Asia are limited and thus require more attention due to a steep rise of osteoporosis and hip fracture incidence projected in this part of the world.     

Bisphenol A and Child Vascular Health: A Preview of Future Heart Disease Risk?

Open in a separate window

Exposures to phthalates and bisphenols have well-documented adverse effects on reproductive health and human development.¹ These endocrine-disrupting chemicals (EDCs) are also associated with obesity, hypertension, and blood vessel lesions in cross-sectional studies of adolescents and adults.^2–5 It is conceivable that processes leading to such damage start early in life and may be affected by prenatal chemical exposure.^6,7 A study recently published in Environmental Health Perspectives examined this question in children followed from gestation into childhood.⁸The authors measured phthalates and bisphenols in urine samples from 935 pregnant Generation R participants during their first, second, and third trimesters. The Generation R Study, based in Rotterdam, the Netherlands, comprises a population-based prospective cohort.⁹ At approximately 10 years of age, the women’s children underwent ultrasounds for two measurements of the common carotid artery: distensibility (elasticity) and intima-media thickness (the thickness between the intima and media layers of the vessel wall). Both distensibility and intima-media thickness reflect vascular health in the whole body^10–12; thicker vessel walls and reduced elasticity are considered distinct but overlapping risk factors for cardiovascular disease in adulthood, such as atherosclerosis.¹³Open in a separate windowThe intima layer of the artery (shown in black) is composed of endothelial cells, and the media layer (shown in pink) is made of smooth muscle and elastic fibers. Combined expansion (diastole) and contraction (systole) of the media layer pushes blood through the artery and controls blood pressure. In this transmission electron micrograph, the intima has accordioned due to contraction of the media. Image: © Steve Gschmeissner/Science Source.The authors analyzed the children’s vascular measurements in association with their mothers’ prenatal levels of three bisphenols [bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF)], low-molecular-weight phthalates as a group, high-molecular-weight phthalates, and three individual phthalates. They found no associations between any of the chemicals and distensibility. However, higher maternal urine concentrations of total bisphenols and of BPA alone were associated with thinner vessel walls in the children’s carotid artery. No associations were found for BPS, BPF, or any phthalate.The association of higher total bisphenol and BPA exposure with thinner—rather than thicker—vessel walls surprised the team initially but is biologically plausible, says first author Sophia Blaauwendraad. “Associations between higher BPA levels and atherosclerosis in adulthood [demonstrated in earlier studies¹⁴] could be due to oxidative stress that accelerates the formation of atherosclerotic plaques and thickens the vascular wall,” says Blaauwendraad, a physician and graduate student in epidemiology under senior coauthor Vincent Jaddoe at Rotterdam’s Erasmus University Medical Center. Fetal exposures, on the other hand, may be associated with an underdevelopment of the vasculature in childhood, the authors speculate. However, Blaauwendraad says, as yet no prospective studies have tracked intima-media thickness measures from childhood to adulthood.¹⁵Nikki Posnack, an assistant professor of pharmacology, physiology, and pediatrics at Children’s National Hospital in Washington, DC, says the study’s strengths include its large sample size and measurements of several subtypes of phthalates and bisphenols at three different time points during pregnancy. Posnack, who was not involved in the research, says, “This is a compelling study that opens up new opportunities for mechanistic follow-up studies in model systems.” Such studies could examine whether BPA disrupts development of blood vessels and alters their contractile properties,¹⁶ similar to the chemical’s disruption of hormonal regulation.According to Lars Lind, a professor of medicine at Uppsala University in Sweden, who also was not involved in the project, studying the effect of the chemicals on early vascular changes in animal models would be worthwhile and should be accompanied by replication efforts in other human birth cohorts. “Since the findings were unexpected, replication is critical to increase our faith in them,” says Lind. “But it is possible that these chemicals may have different effects at the fetal stage than later in life.”The association with total bisphenols appears to have been driven mainly by BPA; BPS and BPF were below the limit of detection in more than half the samples, possibly because they were collected in 2002–2006, when these chemicals were used less than today. However, human exposure to these BPA replacement chemicals has been increasing.¹⁷ “With that in mind,” Posnack says, “I think the study fills an important knowledge gap by exploring if exposure to any bisphenols in utero may affect subclinical indicators of vascular disease risk later in life.”     

Oral Health Need and Access to Dental Services: Evidence from the National Survey of Children’s Health, 2007

This study examines associations between parents’ report of their children’s oral health and receipt of a dental visit for preventive care. We conducted a cross-sectional analysis of oral health status and receipt of a preventive dental visit among US children and youth, ages 1–17 years, using data from the 2007 National Survey of Children’s Health (n = 86,764). Survey-weighted logistic regression was used to estimate associations between perceived oral health status and receipt of a preventive dental health visit in the prior 12 months. Overall, 78 % of children and youth received at least one preventive dental health visit in the prior year. Among the youngest children, lower oral health status was associated with higher odds of receiving a preventive dental visit; among older children, lower oral health status was associated with lower odds of receiving a dental visit for preventive care. Use of preventive dental health care is below national target goals. Younger children in worse oral health are more likely, and older youth less likely, to receive preventive dental care. Public health efforts to educate parents to seek early and ongoing preventive oral health care, rather than services in response to problems, may yield oral health benefits later in childhood and over the life course.     

A Case–Control Study of Home Foreclosure,Health Conditions,and Health Care Utilization

Though rates of foreclosure are at a historic high, relatively little is known about the link between foreclosure and health. We performed a case–control study to examine health conditions and health care utilization in the time period prior to foreclosure. Homeowners who received a home foreclosure notice from 2005 to 2008 were matched (by name and address) to a university hospital system in Philadelphia and compared with controls who received care from the hospital system and who lived in the same zip code as cases. Outcome measures included prevalent health conditions and visit history in the 2 years prior to foreclosure. We found that people undergoing foreclosure were similar to controls with regard to age, gender, and insurance status but significantly more likely to be African American. Rates of hypertension and renal disease were significantly higher among cases after adjustment for sociodemographic characteristics. In the 2 years prior to foreclosure, cases were more likely to visit the emergency department, have an outpatient visit, and have a no-show appointment. Cases were less likely to have a primary care physicians (PCP) visit in the 6 months immediately prior to the receipt of a foreclosure notice. The results suggest changes in health care utilization in the time period prior to foreclosure. Policies designed to decrease the incidence of home foreclosure and support people during the process should consider its association with poor health and changes in health care utilization.     

A Review of Research on Buddhism and Health: 1980–2003

Electronic searches of social science and biomedical literature identified 44 empirical studies that specifically investigate Buddhism, meditation, and health. The number of studies increased over time, especially in medical and other health-related fields. The studies were found to differ by geographical region with regard to the emphasis on spiritual, psychological, or physical outcomes. Results from this study are explored with respect to historical trends as well as current variations in scholarship and religious practice between the regions.     

Migration and Persistence of Human Influenza A Viruses,Vietnam, 2001–2008

Understanding global influenza migration and persistence is crucial for vaccine strain selection. Using 240 new human influenza A virus whole genomes collected in Vietnam during 2001–2008, we looked for persistence patterns and migratory connections between Vietnam and other countries. We found that viruses in Vietnam migrate to and from China, Hong Kong, Taiwan, Cambodia, Japan, South Korea, and the United States. We attempted to reduce geographic bias by generating phylogenies subsampled at the year and country levels. However, migration events in these phylogenies were still driven by the presence or absence of sequence data, indicating that an epidemiologic study design that controls for prevalence is required for robust migration analysis. With whole-genome data, most migration events are not detectable from the phylogeny of the hemagglutinin segment alone, although general migratory relationships between Vietnam and other countries are visible in the hemagglutinin phylogeny. It is possible that virus lineages in Vietnam persisted for >1 year.     

Human papillomavirus vaccination coverage among females and males,National Health and Nutrition Examination Survey,United States, 2007–2016

BackgroundHuman papillomavirus (HPV) vaccination has been routinely recommended at age 11–12 years in the United States for females since 2006 and males since 2011. Coverage can be estimated using self/parent-reported HPV vaccination collected in the National Health and Nutrition Examination Survey (NHANES) for a wider age range than other national surveys. We assessed vaccination coverage in 2015–2016, temporal trends by age, and the validity of self/parent-reported vaccination status.MethodsParticipants aged 9–59 years completed an interview collecting demographic and vaccination information. Weighted coverage was estimated for two-year NHANES cycles by age group for 2007–2008 to 2015–2016 for females (N = 14318) and 2011–2012 to 2015–2016 for males (N = 7847). Temporal trends in coverage were assessed from 2007–2008 to 2011–2012 for females and from 2011–2012 to 2015–2016 for both sexes. Sensitivity and specificity of self/parent-reported vaccination were assessed using provider-verified vaccination records from a pilot study in 14–29 year-olds.ResultsIn 2015–2016, ≥1 dose coverage among females was highest in 14–19 (54.7%) and 20–24 (56.0%) year-olds and lower in successively older age groups. Among males, ≥1 dose coverage was highest in 14–19 year-olds (39.5%) and lower at older ages. Coverage was similar in 9–13 year-old females and males. Between 2007–2008 and 2011–2012, there were increases among females younger than 30 years. Between 2011–2012 and 2015–2016, there were increases among female age groups including 20–39 year-olds; male coverage increased among ages 9–13, 14–19, and 20–24 years. Self/parent-reported receipt of ≥1 dose had a sensitivity and specificity of 87.0% and 83.3%. Performance was lower for 3 doses.ConclusionsWhile overall HPV vaccination coverage remains low, it is higher in females than males, except in 9–13 year-olds. There have been increases in coverage among many age groups, but coverage has stalled in younger females. Adequate validity was demonstrated for self/parent-reported vaccination of ≥1 dose, but not 3 doses, in a pilot study.     

A Unified Probabilistic Framework for Dose–Response Assessment of Human Health Effects

Background

When chemical health hazards have been identified, probabilistic dose–response assessment (“hazard characterization”) quantifies uncertainty and/or variability in toxicity as a function of human exposure. Existing probabilistic approaches differ for different types of endpoints or modes-of-action, lacking a unifying framework.

Objectives

We developed a unified framework for probabilistic dose–response assessment.

Methods

We established a framework based on four principles: a) individual and population dose responses are distinct; b) dose–response relationships for all (including quantal) endpoints can be recast as relating to an underlying continuous measure of response at the individual level; c) for effects relevant to humans, “effect metrics” can be specified to define “toxicologically equivalent” sizes for this underlying individual response; and d) dose–response assessment requires making adjustments and accounting for uncertainty and variability. We then derived a step-by-step probabilistic approach for dose–response assessment of animal toxicology data similar to how nonprobabilistic reference doses are derived, illustrating the approach with example non-cancer and cancer datasets.

Results

Probabilistically derived exposure limits are based on estimating a “target human dose” (HD_M^I), which requires risk management–informed choices for the magnitude (M) of individual effect being protected against, the remaining incidence (I) of individuals with effects ≥ M in the population, and the percent confidence. In the example datasets, probabilistically derived 90% confidence intervals for HD_M^I values span a 40- to 60-fold range, where I = 1% of the population experiences ≥ M = 1%–10% effect sizes.

Conclusions

Although some implementation challenges remain, this unified probabilistic framework can provide substantially more complete and transparent characterization of chemical hazards and support better-informed risk management decisions.

Citation

Chiu WA, Slob W. 2015. A unified probabilistic framework for dose–response assessment of human health effects. Environ Health Perspect 123:1241–1254; http://dx.doi.org/10.1289/ehp.1409385     

Perioperative Cardiovascular Medicine: An Update of the Literature 2013–2014

Abstract

Perioperative medicine is an important and rapidly expanding area of interest across multiple specialties, including internal medicine, anesthesiology, surgery, cardiology, and hospital medicine. A multispecialty team approach that ensures the best possible patient outcomes has fostered collaborative strategies across the continuum of patient care. Staying current in this multidisciplinary field is difficult, because physicians interested in perioperative medicine would need to review multiple specialty journals on a regular basis. To facilitate this process, the authors performed a focused review of this literature published in 2013 and early 2014. In this update, key articles are reviewed that potentially impact clinical practice in perioperative cardiovascular risk prediction and risk management.     

Are Environmental Levels of Bisphenol A Associated with Reproductive Function in Fertile Men?

Background

Rodent and in vitro studies have demonstrated the estrogenicity of bisphenol A (BPA). However, few studies have examined the relationship between human exposure to BPA and male reproductive function.

Objectives

We investigated the relationships between environmental BPA exposure and reproductive parameters, including semen quality and male reproductive hormones, in prospectively recruited fertile men.

Methods

Participants (n = 375) were partners of pregnant women who participated in the Study for Future Families in four U.S. cities, and all of the men provided blood, semen, and urine samples. BPA was measured in urine. Serum samples were analyzed for reproductive hormones, including follicle-stimulating hormone, luteinizing hormone (LH), testosterone, inhibin B, estradiol, and sex hormone–binding globulin (SHBG), as well as the free androgen index (FAI). Semen analyses were performed according to World Health Organization criteria. Pearson correlations were used for unadjusted analyses, and multiple linear regression analyses were used to examine associations controlling for age, body mass index, smoking, ethnicity, urinary creatinine concentration, time of sample collection, and duration of abstinence.

Results

After multivariate adjustment, we observed no significant associations between any semen parameter and urinary BPA concentration. However, a significant inverse association was found between urinary BPA concentration and FAI levels and the FAI/LH ratio, as well as a significant positive association between BPA and SHBG.

Conclusions

Our results suggest that, in fertile men, exposure to low environmental levels of BPA may be associated with a modest reduction in markers of free testosterone, but any effects on reproductive function are likely to be small, and of uncertain clinical significance.     

Increasing the Number of Trained Health and Safety Professionals in Agricultural Medicine: Evaluation of the “Building Capacity” Program, 2007–2013

ABSTRACT

The University of Iowa began training health care professionals to care for farmers’ occupational health needs since 1974. In order to geographically expand this training to practicing health and safety professionals, the “Building Capacity: A National Resource of Agricultural Medicine Professionals” program was developed and launched in 2006. The model began in 1987 as a program of Iowa’s Center for Agricultural Safety and Health. In 2006, with funding from the National Institute for Occupational Safety and Health (NIOSH), Great Plains Center for Agricultural Health (GPCAH), the program was expanded beyond the Iowa borders. The principal component of the program, the 40-hour course, Agricultural Medicine: Occupational and Environmental Health for Rural Health Professionals—the Core Course (AMCC) is now being offered to health and safety professionals in nine states in the United States, in Australia, and a modified version presented in Turkey. An initial paper evaluated the first phase of the program, years 2007–2010. This paper compares the first phase (2007–2010) with the second phase (2011–2013), which has involved over 500 health and safety professionals. This paper also describes evaluation of the course and changes resulting from the evaluation. Finally, this paper describes best practices for operating this program and makes recommendations for future courses, as well as other trainings within the field.     

Maternal Sociodemographic Characteristics,Experiences and Health Behaviors Associated with Postpartum Care Utilization: Evidence from Maryland PRAMS Dataset, 2012–2013

Objectives Postpartum visits are increasingly recognized as a window of opportunity for health care providers to counsel new mothers and promote healthy behaviors, including increasing contraceptive use and screening for postpartum depression. In Maryland, there is a lack of research on postpartum visit (PPV) attendance and the specific risk factors associated with not receiving postpartum care. In this study, we estimated the proportion of mothers in Maryland who attended a PPV and assessed maternal sociodemographic characteristics and health behaviors associated with PPV non-attendance. Methods Data were analyzed from the 2012 and 2013 Maryland Pregnancy Risk Assessment Monitoring System (n?=?2204). Bivariate and multivariable logistic regression were performed to examine the association between covariates and PPV non-attendance. Results Overall, 89.6% of women reported PPV attendance. Bivariate analyses between maternal sociodemographic and health behavior characteristics and PPV non-attendance indicated that being unmarried (OR 3.03, 95% CI 2.12–4.31), experiencing infant loss (OR 7.17, 95% CI 2.57–19.97), working during pregnancy (OR 0.44, 95% CI 0.31–0.63) and not receiving dental care (OR 2.03, 95% CI 1.43–2.88) as significant risk factors for PPV non-attendance. After controlling for known and theoretical confounders, experiencing an infant loss (aOR 5.18, 95% CI 1.54–17.4), not receiving dental care (aOR 1.54, 95% CI 1.06–2.26) and working during pregnancy (aOR 0.61, 95% CI 0.41–0.93) emerged as strong predictors of PPV non-attendance. Conclusions for Practice Mothers who recently experienced an infant death were at greatest risk for not attending a PPV, suggesting the need to establish comprehensive support networks, including grief counseling and additional service reminders for mothers who experienced an infant death.     

Sexual and Reproductive Health Services and Related Health Information on Pregnancy Resource Center Websites: A Statewide Content Analysis

Background

Pregnancy resource centers (PRCs) are nonprofit organizations with a primary mission of promoting childbirth among pregnant women. Given a new state grant program to publicly fund PRCs, we analyzed Georgia PRC websites to describe advertised services and related health information.