Association of Cumulative Lead Exposure with Parkinson’s Disease

Background

Research using reconstructed exposure histories has suggested an association between heavy metal exposures, including lead, and Parkinson’s disease (PD), but the only study that used bone lead, a biomarker of cumulative lead exposure, found a nonsignificant increase in risk of PD with increasing bone lead.

Objectives

We sought to assess the association between bone lead and PD.

Methods

Bone lead concentrations were measured using ¹⁰⁹Cd excited K-shell X-ray fluorescence from 330 PD patients (216 men, 114 women) and 308 controls (172 men, 136 women) recruited from four clinics for movement disorders and general-community cohorts. Adjusted odds ratios (ORs) for PD were calculated using logistic regression.

Results

The average age of cases and controls at bone lead measurement was 67 (SD = 10) and 69 (SD = 9) years of age, respectively. In primary analyses of cases and controls recruited from the same groups, compared with the lowest quartile of tibia lead, the OR for PD in the highest quartile was 3.21 [95% confidence interval (CI), 1.17–8.83]. Results were similar but slightly weaker in analyses restricted to cases and controls recruited from the movement disorders clinics only (fourth-quartile OR = 2.57; 95% CI, 1.11–5.93) or when we included controls recruited from sites that did not also contribute cases (fourth-quartile OR = 1.91; 95% CI, 1.01–3.60). We found no association with patella bone lead.

Conclusions

These findings, using an objective biological marker of cumulative lead exposure among typical PD patients seen in our movement disorders clinics, strengthen the evidence that cumulative exposure to lead increases the risk of PD.     

Sex-Specific Effects of Fetal Exposure to the 1959–1961 Chinese Famine on Risk of Adult Hypertension

Previous research is inconsistent about the effects of prenatal famine exposure on risk of adult hypertension. Follow-up of persons exposed to the 1959–1961 Chinese famine, the largest in human history, provides an opportunity to examine the long-term impact of prenatal famine exposure on adult cardiovascular disease (CVD). We investigated the effects of fetal-infant exposure to the famine on risk of hypertension in adulthood. We included 1,415 participants from the 2009 China Health and Nutrition Survey born September 1, 1956–December 31, 1964. Blood pressure (BP) measurements, self-reported previous diagnosis of hypertension and current anti-hypertension drug use were obtained from the survey. Differences in mean BP and risk of adult hypertension by famine exposure status were determined using linear and logistic regression analyses, after adjusting for confounders. Women with fetal-infant exposure to famine had higher mean systolic blood pressure (4.24 mmHg; 95 % confidence interval (CI) 1.50–6.98) than those unexposed. They also had increased odds of a prior diagnosis of hypertension (odds ratio (OR) 2.16; 95 % CI 1.16–4.02), and were more likely to be currently taking anti-hypertensive medications (OR 2.81; 95 % CI 1.32–5.97) than unexposed women after adjusting for covariates. No statistically significant increases in mean BP or hypertension were seen among men. Exposure to famine during the fetal-infant period or early childhood has deleterious effects on adult health, but the effects may be greater for women. Gender-specific intervention strategies for CVD may be warranted for populations exposed to under-nutrition during critical time periods of fetal development.     

Effects of Media Messages on Parent–Child Sexual Communication

Parent–child communication about sex is an important reproductive health outcome. Consistent, positive perceptions of communication by parents and children can promote behavioral outcomes such as delaying sexual debut and increasing contraceptive use. The authors investigated whether exposure to messages from the Parents Speak Up National Campaign (PSUNC), a social marketing campaign to promote increased parent–child sexual communication, led to increased children's self-reports of communication. Also, the authors examined whether PSUNC message exposure increased agreement about communication between parents and their children. In a randomized experimental design, the authors surveyed children of parents exposed and not exposed to PSUNC messages. Parents and children completed online instruments asking matched questions about sexual attitudes, beliefs, and communication. The authors matched 394 parents and children for analysis. They used ordinal logistic regression modeling and kappa statistics. Children of parents exposed to PSUNC messages were more likely to (a) report sexual communication than were those not exposed and (b) agree with their parents about extent and content. Parent–child pairs of the same gender, younger pairs, and non-White pairs were more likely to agree. Overall, PSUNC message exposure appears to have promoted more extensive sexual communication. Future research should examine behavioral mechanisms and message receptivity among subgroups of parents and children.     

Association of Exposure to Phthalates with Endometriosis and Uterine Leiomyomata: Findings from NHANES, 1999–2004

Background

Phthalates are ubiquitous chemicals used in consumer products. Some phthalates are reproductive toxicants in experimental animals, but human data are limited.

Objective

We conducted a cross-sectional study of urinary phthalate metabolite concentrations in relation to self-reported history of endometriosis and uterine leiomyomata among 1,227 women 20–54 years of age from three cycles of the National Health and Nutrition Examination Survey (NHANES), 1999–2004.

Methods

We examined four phthalate metabolites: mono(2-ethylhexyl) phthalate (MEHP), monobutyl phthalate (MBP), monoethyl phthalate (MEP), and monobenzyl phthalate (MBzP). From the last two NHANES cycles, we also examined mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP). We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for potential confounders.

Results

Eighty-seven (7%) and 151 (12%) women reported diagnoses of endometriosis and leiomyomata, respectively. The ORs comparing the highest versus lowest three quartiles of urinary MBP were 1.36 (95% CI, 0.77–2.41) for endometriosis, 1.56 (95% CI, 0.93–2.61) for leiomyomata, and 1.71 (95% CI, 1.07–2.75) for both conditions combined. The corresponding ORs for MEHP were 0.44 (95% CI, 0.19–1.02) for endometriosis, 0.63 (95% CI, 0.35–1.12) for leiomyomata, and 0.59 (95% CI, 0.37–0.95) for both conditions combined. Findings for MEHHP and MEOHP agreed with findings for MEHP with respect to endometriosis only. We observed null associations for MEP and MBzP. Associations were similar when we excluded women diagnosed > 7 years before their NHANES evaluation.

Conclusion

The positive associations for MBP and inverse associations for MEHP in relation to endometriosis and leiomyomata warrant investigation in prospective studies.     

The Effects of Ethno-cultural Origin–Destination Interactions on Immigrants’ Longevity

A large body of research has documented an immigrant mortality advantage. However, we still do not know enough about how interactions between the characteristics of origin and destinations countries shape variabilities in immigrants’ experiences and health. In this paper, we examine the effects of ethno-cultural similarities and differences between the country of origin and the country of destination on immigrants’ longevity. We use meta-regression methods to examine data on 78 origin and 16 destination countries (1092 risk estimates from 69 studies). In contrast to expectations from approaches that focus on immigration/acculturation stress, we found that a shared official linguistic family, moving to a country where one is not likely to be considered a visible minority, and more integrative immigration policies actually reduce or even eliminate the immigrant mortality advantage. We discuss potential explanations for these findings and argue that selection mechanisms provide a better account.

     

Impact of New-Generation Lipid Emulsions on Cellular Mechanisms of Parenteral Nutrition–Associated Liver Disease

Parenteral nutrition (PN) is a life-saving nutritional support for a large population of hospitalized infants, and lipids make a substantial contribution to their energy and essential fatty acid (FA) needs. A challenge in the care of these infants is that their metabolic needs require prolonged PN support that increases the risk of PN-associated liver disease (PNALD). In recent years, the emergence of new parenteral lipid emulsions containing different source lipids and FA profiles has created nutritional alternatives to the first-generation, soybean oil–based lipid emulsion Intralipid. The limited U.S. introduction of the new-generation fish-oil emulsion Omegaven has generated promising results in infants with PNALD and spawned a renewed interest in how PN and lipid emulsions, in particular, contribute to this disease. Studies suggest that the lipid load and constituents, such as specific FAs, ratio of n–3 (ω-3) to n–6 (ω-6) long-chain polyunsaturated FAs, phytosterols, and vitamin E content, may be involved. There is an existing literature describing the molecular mechanisms whereby these specific nutrients affect hepatic metabolism and function via lipid and bile acid sensing nuclear receptors, such as peroxisome proliferator–activated receptor α, liver X receptor, and farnesoid X receptor, yet virtually no information as to how they interact and modulate liver function in the context of PN in pediatric patients or animal models. This article will review the recent development of parenteral lipid emulsions and their influence on PNALD and highlight some of the emerging molecular mechanisms that may explain the effects on liver function and disease.     

The Exposure Effects of Online Model Pictures and Weight-Related Persuasive Messages on Women’s Weight-Loss Planned Behaviors

This study examined how exposure to pictures of women with different body sizes (thin, obese), physical attractiveness levels (attractive, unattractive), along with exposure to weight-related messages (pro-anorexia, anti-anorexia) embedded in a fashion website affected female participants’ planned behavior toward weight loss. Participants exposed to attractive model pictures showed higher intentions, attitudes, and subjective norms to lose weight compared with unattractive models. Additionally, participants exposed to thin and attractive model pictures indicated the highest attitudes and self-efficacy to lose weight, whereas those exposed to thin and unattractive model pictures indicated the lowest. Furthermore, weight-related messages moderated the effect of model appearance (body size and attractiveness) on controllability of weight-loss activities. However, website pictures’ body size differences had no main effects on planned behavior toward weight loss. These effects are discussed in the light of social comparison mechanisms.     

New Ventilation Systems at Select Schools in Sweden—Effects on Asthma and Exposure

The air-exchange rate is often low in schools. The authors studied the possible impact of improving school ventilation on health and exposure of pupils. Questionnaire data on allergies, asthma, and asthmatic symptoms were obtained in 1993 and 1995 for 1,476 primary- and secondary-school pupils in 39 randomly selected schools. Various exposure factors were measured in 1993 and 1995 in approximately 100 classrooms. In 12% of the classrooms, new ventilation systems were installed between 1993 and 1995; the subsequent air-exchange rate increased and the relative humidity and concentration of several airborne pollutants were reduced compared with classrooms in nonimproved buildings. The reporting of at least one asthmatic symptom and the reporting of more asthmatic symptoms in 1995 than in 1993 were less common among the 143 pupils who attended schools with new ventilation systems.     

Parent–Adolescent Relationship Quality and Nondisclosure as Mediators of the Association Between Exposure to Community Violence and Psychological Distress

Background

African American youth residing in urban poverty have been shown to be at increased risk for exposure to violence and for psychological symptoms, but there has been little investigation of mediating processes that might explain this association.

Objectives

This study tested the quality of parent–adolescent relationships and adolescent nondisclosure to adults as mediating mechanisms through which exposure to community violence may lead to psychological symptoms.

Methods

The current study surveyed a sample of 152 low-income urban African American early adolescents (aged 12–14). Participants completed self-report questionnaires assessing exposure to community violence, nondisclosure, parent–adolescent relationship, and psychological symptoms (i.e., internalizing and externalizing symptoms).

Results

Path analyses revealed that parent–adolescent relationship quality and nondisclosure both functioned as mediators of the relation between exposure to community violence and both internalizing and externalizing symptoms, though significant direct effects for violence exposure on externalizing symptoms remained. Decomposition of effects revealed that nondisclosure was a stronger mediator than parent–adolescent relationship quality. Results also indicated that exposure to violence can lead to externalizing (but not internalizing) symptoms first by way of parent–adolescent relationship quality and then nondisclosure.

Conclusions

Combined, these findings suggest that the development of preventive interventions designed to assist adults and parents improve communication and strengthen relationships with adolescents might reduce the negative effects of exposure to community violence on adolescent mental health.

     

Effects of Oro-Sensory Exposure on Satiation and Underlying Neurophysiological Mechanisms—What Do We Know So Far?

The mouth is the first part of the gastrointestinal tract. During mastication sensory signals from the mouth, so-called oro-sensory exposure, elicit physiological signals that affect satiation and food intake. It has been established that a longer duration of oro-sensory exposure leads to earlier satiation. In addition, foods with more intense sweet or salty taste induce earlier satiation compared to foods that are equally palatable, but with lower taste intensity. Oro-sensory exposure to food affects satiation by direct signaling via the brainstem to higher cortical regions involved in taste and reward, including the nucleus accumbens and the insula. There is little evidence that oro-sensory exposure affects satiation indirectly through either hormone responses or gastric signals. Critical brain areas for satiation, such as the brainstem, should be studied more intensively to better understand the neurophysiological mechanisms underlying the process of satiation. Furthermore, it is essential to increase the understanding of how of highly automated eating behaviors, such as oral processing and eating rate, are formed during early childhood. A better understanding of the aforementioned mechanisms provides fundamental insight in relation to strategies to prevent overconsumption and the development of obesity in future generations.     

Effects of Sublethal Chronic Copper Exposure on the Growth and Reproductive Success of the Florida Apple Snail (Pomacea paludosa)

Florida apple snails (Pomacea paludosa) were exposed to three concentrations of copper (Cu), in water (8 μg/L, 16 μg/L, 24 μg/L), for one generation to examine uptake and the effects on survival, growth, and reproduction of the F₀ generation and survival, growth, and whole body Cu of the F₁ generation. During a 9-month Cu exposure, apple snails exposed to 8–16 μg/L Cu had high Cu accumulation (whole body, foot, viscera, and shell) and significantly reduced clutch production (8–16 μg/L) and egg hatching (16 μg/L). Apple snails exposed to the 24 μg/L Cu had low survival and the treatment was therefore terminated. Concentrations of minerals (Na⁺, K⁺, Mg²⁺, Ca²⁺) in tissues were maintained regardless of Cu exposure, but the distribution of Cu in the body of snails differed, depending on exposure concentrations. Higher exposure concentrations resulted in a greater percentage of Cu accumulated in the viscera of the snail. Copper exposure to the F₀ generation did not affect the survival, growth, or whole body Cu concentrations in the F₁ generation. These finding are significant, given the importance of the Florida apple snail in the Everglades food chain. Changes in the abundance of apple snail populations, as a result of Cu exposure, could ultimately affect foraging success of predators.     

Effects of the 1997–1998 El Ni?o Episode on Community Rates of Diarrhea

Objectives. To improve our understanding of climate variability and diarrheal disease at the community level and inform predictions for future climate change scenarios, we examined whether the El Niño climate pattern is associated with increased rates of diarrhea among Peruvian children.Methods. We analyzed daily surveillance data for 367 children aged 0 to 12 years from 2 cohorts in a peri-urban shantytown in Lima, Peru, 1995 through 1998. We stratified diarrheal incidence by 6-month age categories, season, and El Niño, and modeled between-subject heterogeneity with random effects Poisson models.Results. Spring diarrheal incidence increased by 55% during El Niño compared with before El Niño. This increase was most acute among children older than 60 months, for whom the risk of a diarrheal episode during the El Niño spring was nearly 100% greater (relative risk = 1.96; 95% confidence interval = 1.24, 3.09).Conclusions. El Niño–associated climate variability affects community rates of diarrhea, particularly during the cooler seasons and among older children. Public health officials should develop preventive strategies for future El Niño episodes to mitigate the increased risk of diarrheal disease in vulnerable communities.The effect of weather on disease transmission is well recognized for many infectious diseases that exhibit seasonal patterns,1 including diarrhea,2,3 respiratory infections,4 malaria,5 and dengue.6 There is growing concern that severe weather changes resulting from El Niño episodes and global climate change directly affect human health.7 Diarrheal illnesses are among the highest disease burdens in children younger than 5 years of age worldwide8 and are predicted to increase with climate change. However, specific estimates for the magnitude of this increase in the community setting remain uncertain, in part because epidemiological data on the relationship between community rates of diarrhea and extreme weather variability are scarce.9 Although the relationship between specific weather variables and infectious disease has been examined extensively with retrospective, hospital-based data,10–14 data from prospective population-based cohort studies are limited. Determining the effects of El Niño on rates of diarrhea with a cohort study would greatly improve our understanding of climate variability and diarrheal disease at the community level and inform predictions for other extreme weather episodes or future climate change scenarios.15The El Niño southern oscillation (ENSO) is a main driver of global interannual weather variation. Occurring every 3 to 7 years, the ENSO phenomenon leads to extreme worldwide weather events, such as heavy flooding and drought.16 The ENSO provides health researchers with an opportunity to model effects of local climate anomalies on infectious disease dynamics,17 and it has been linked to changes in rates of cholera,18–21 diarrhea,11,22,23 malaria,10 dengue,24 hantavirus,25 viral pneumonia,26 and Rift Valley fever.27The 1997–1998 El Niño episode altered weather conditions around the world—particularly severely along the Peruvian coastline. This El Niño episode has been described as the strongest yet recorded.28 Previously, we found that the number of pediatric hospital admissions for diarrheal diseases in Lima, Peru, increased substantially during this episode, especially during the winter months.11 A separate study found similar results for adults.22 In this study, we sought to examine the effects of the 1997–1998 El Niño episode on rates of childhood diarrhea and several parasitic agents in a peri-urban Peruvian community with cohort studies conducted between June 1995 and August 1998.     

Effects of curcuminoid supplement on cardiac autonomic status in high-fat–induced obese rats

ObjectiveSudden cardiac death in obesity is frequently associated with sympathetic activation due to an elevated plasma free-fatty acid (FFA) level. Curcuminoids, the phenolic yellowish pigments of turmeric, display antioxidative and lipid-lowering activities. We hypothesized that curcuminoids ameliorate cardiac sympathovagal disturbance in high-fat–induced obese rats.MethodsMale Wistar rats were divided into five groups. A normal-diet control (NDC) group received a normal-fat diet (12% calories as fat) and a high-fat–diet control (HDC) group received a high-fat diet (60% calories as fat) for 12 wk. Three other groups received high-fat diets with curcuminoid supplement at concentrations of 30 mg (HD₃₀), 60 mg (HD₆₀), and 90 mg (HD₉₀) per kilogram of body weight every day for 12 wk. Heart rate variability was determined to assess cardiac autonomic status at weeks 0 and 12.ResultsBody weight, visceral fat mass, plasma FFA, and glucose levels increased significantly in the HDC group compared with the NDC group. Low frequency power in normalized units (LFnu) and the ratio of LF to high-frequency power (HF) in the HDC group were significantly higher, whereas HFnu in the HDC group was significantly lower than in the NDC group. Plasma FFA levels correlated significantly with LFnu and LF/HF ratio. Compared with the HDC group, plasma FFA, glucose levels, LFnu, and LF/HF ratio were significantly decreased in the HF₃₀, HF₆₀, and HF₉₀ groups.ConclusionElevated plasma FFA in high-fat–induced obese rats is associated with an increased LF/HF ratio, an expression of sympathovagal disturbance. Curcuminoid supplementation ameliorates cardiac autonomic imbalance in high-fat–fed rats, probably due to its lipid-lowering effect.