Transition to a market economy and chronic psychosocial stress in northern Laos: An exploratory study of urinary free cortisol in rural residents.

OBJECTIVES: The indigenous population in northern Laos has experienced a transition from self-sufficiency to a market-oriented economy, which may have brought about unprecedented chronic psychosocial stress. This study examined the association between the transition to a market economy and urinary free cortisol (UFC) concentration as a stress biomarker among rural residents of three villages with different degrees of integration into the market economy. METHODS: An interview survey and urine sample collection were conducted in August 2018 and March 2019. We measured the UFC concentration in spot urine samples collected in the morning from participants aged 20-60 years (n = 168) using an enzyme-linked immunosorbent assay. Multiple linear regression analysis was performed to examine differences in UFC concentrations among villages by sex, with time of arrival for the survey, age, and body mass index included as covariates. RESULTS: The UFC concentration was higher in men living in the village with the highest degree of integration into the market economy than in those in the two villages with a lower dependence on cash, possibly linking increased stress levels with a change in employment type. This trend was not observed in women. CONCLUSION: Socioeconomic changes incidental to a transition to a market economy may increase the stress levels of men in northern Laos.

The search for aliens within us: a review of evidence and theory regarding the foetal microbiome.

The microbiome is believed to be established during the birthing process through exposure to the maternal microbiome and immediate external environment. The absence of a microbiome prior to birth is based on the sterile womb hypothesis, which was formulated at the beginning of the 20th century and is supported primarily by the culture-based approach in microbiological studies.Findings of bacterial presence in products of fertilization such as the placenta, amniotic fluid, foetal membranes, and umbilical cord blood in studies using next-generation DNA sequencing technologies began to challenge the sterile nature of the intrauterine environment during gestation. These studies have been mainly criticized by their approach to contamination and inconclusive evidence of viability. The implications of bacterial presence in utero are far reaching in medicine and basic sciences. If commensal bacteria exist in the foetus, antibiotic therapies in pregnancy particularly for asymptomatic cases will need to be re-evaluated. Experimental studies utilizing gnotobiology may also be impacted by a realignment of theory.This review of existing literature aims to provide insight into the existence of bacteria in utero, specifically the foetal microbiome through analysis of experimental evidence and theoretical concepts, and to suggest approaches that may further provide clarity into this inquiry.

Food store accessibility affects nutritional intake through shopping frequency and food intake in middle-aged to older adults in rural Nagasaki, Japan.

OBJECTIVES: The food environment is an important determinant of dietary and nutritional intake, but studies thus far have reported mixed results. We examined associations between food store accessibility and nutritional intake among middle-aged to older adults in rural Japan using data from a questionnaire survey of national health insurance enrollees. METHODS: The survey was conducted in Nagasaki, Japan, for individuals aged 40-74 years. Direct distances from home and food store density were estimated using a geographic information system (GIS). We focused on protein, vitamin D, and calcium intake for their preventive effects on frailty and sarcopenia. To examine the effects of food store accessibility on nutritional intake, we hypothesized a model with a chain of associations of food store accessibility, shopping frequency, food intake frequency, and nutritional intake. We performed a path analyses to explore the food items to be included in the models, associations between the variables, and fitness of the models. RESULTS: We obtained final models with satisfactory fit indices. The resultant models included significant associations between: 1) accessibility indicators and shopping frequency, 2) shopping frequency and intake frequency for two or four categories of food, and 3) intake frequency and nutritional intake. CONCLUSIONS: The results demonstrated that accessibility to food stores, assessed in terms of direct distance from home and food store density, can affect the intake of protein, vitamin D, and calcium through the effect on shopping frequency and intake frequency of some categories of food items, among middle-aged to older adults in Nagasaki, Japan.

Impact of modernization on urinary concentrations of arsenic, cadmium, lead, and selenium in rural residents of Northern Laos.

OBJECTIVES: The impacts of modernization on toxic heavy metal exposure and essential trace element intake in indigenous populations of subsistence societies are unknown. We assessed urinary trace element concentrations in rural residents of Northern Laos and examined associations with levels of modernization. METHODS: A cross-sectional study was conducted comprising 380 residents of three villages in Northern Laos with different levels of modernization. We surveyed general characteristics and measured the weight and height of 341 participants. Arsenic, cadmium, lead, and selenium concentrations were measured in spot urine samples by inductively coupled plasma mass spectrometry. We examined associations between urinary trace element concentrations and variables related to modernization (village, roofing material, possessions index [total number of possessions], and body mass index [BMI]) using multilevel analyses with household as a random effect, after adjusting for sex, age, and smoking status. RESULTS: Urinary concentrations of arsenic and cadmium were high, while those of lead and selenium were low in comparison to previous reports of populations in non-contaminated regions or without excess/deficiency. We observed associations between urinary trace element concentrations and village-level modernization: lead and selenium concentrations were higher in more modernized villages and cadmium concentration was highest in the least modernized village. Urinary arsenic concentration was not predicted by the modernization level of a village, although we observed significant differences among villages. In addition, urinary selenium concentration was higher in participants inhabiting more modernized houses. CONCLUSION: Modernization of villages may impact toxic heavy metal exposure and selenium intake in rural residents of Northern Laos.

Association between the dietary inflammatory index and disability in Japanese older people.

OBJECTIVES: To examine the demographic and lifestyle characteristics related to the dietary inflammatory index (DII™) score and to evaluate the association between DII score and disability among older people in Japan. DESIGN: Cross-sectional design. The DII score was calculated from nutrient intake information obtained from a FFQ. Disability was assessed using the Tokyo Metropolitan Institute of Gerontology Index of Competence questionnaire. Overall disability and disability in each component of everyday competence, that is, instrumental activities of daily living (IADL), intellectual activities and social participation, were assessed. Those with a deficit in one or more activities were defined as disabled. SETTING: Five non-urban areas in Japan. PARTICIPANTS: A total of 1642 Japanese older people aged 65 years or older. RESULTS: Women, residents of Oga-shi, and those with a higher education and greater frequency of shopping followed a more anti-inflammatory diet, while those living alone and residents of Minamiawaji-shi had higher dietary inflammation. A pro-inflammatory diet was associated with higher odds of overall disability and disability in each component of competence: overall disability, OR (95 % CI) = 1·26 (1·16, 1·36); IADL disability, OR (95 % CI) = 1·16 (1·07, 1·26); disability in intellectual activities, OR (95 % CI): 1·30 (1·20, 1·40); and disability in social participation, OR (95 % CI) = 1·20 (1·11, 1·29). CONCLUSIONS: Sex, living alone, education, frequency of shopping and area of residence were shown to be determinants of DII score in Japanese older people. DII score was positively associated with disability.

Associations between urinary heavy metal concentrations and blood pressure in residents of Asian countries.

BACKGROUND: Previous studies have suggested that exposures to heavy metals (arsenic, cadmium, lead, and selenium) may be associated with differences in blood pressure. However, the findings of these studies have been inconsistent. This study was performed to examine the associations between urinary heavy metal concentrations and blood pressure among residents of four Asian countries (Bangladesh, Indonesia, Nepal, and Vietnam). METHODS: This cross-sectional study examined 1899 adults in four Asian countries. Urinary concentrations of heavy metals were measured by inductively coupled plasma mass spectrometry. A questionnaire survey was administered regarding individual characteristics. Anthropometric measurements (height and weight) were performed. Systolic and diastolic blood pressures were measured after a short rest. Multiple linear regression models were applied to investigate associations between urinary heavy metal concentrations and blood pressure after adjustments for age, sex, and body mass index. RESULTS: The geometric means of the urinary concentrations of arsenic, cadmium, lead, and selenium were 84.6, 0.885, 2.09, and 16.5 µg/g creatinine, respectively. The urinary arsenic concentrations were slightly higher than those typically reported in non-polluted populations, while urinary cadmium, lead, and selenium concentrations were equivalent or slightly lower. The urinary lead concentrations were positively associated with both systolic and diastolic blood pressure, but urinary selenium concentrations were negatively associated with them. CONCLUSIONS: Variations in the urinary concentrations of lead and selenium were associated with blood pressure at low levels of exposure/intake.

Factors Affecting Undernutrition among School Children in Cebu, Philippines.

School children in vulnerable areas continue to be at risk for undernutrition. This study investigated the factors associated with the nutritional status of school children in a rural municipality in Cebu, Philippines. Children aged 6-12 years (n = 327) and their parents were asked to participate. Children's anthropometric measurements were taken in schools, while interviews and measurements of parents were conducted at home. Children's nutritional status was assessed using height-for-age (HAZ) and weight-for-age (WAZ) z scores, while body mass index (BMI) was used for parents. Children's dietary patterns and physical activity, and household characteristics, such as food insecurity, eating practices, water/sanitation/hand washing facilities, and sociodemographic status, were collected. Of 327 school children, 37.3% were stunted, while 35.1% were underweight in this rural community. HAZ and WAZ were negatively associated with household size, and positively associated with household income and parental BMI in multivariate least-squares regression models. Severe food insecurity was negatively associated with WAZ, which suggested that the experiences of severe food insecurity (i.e., not eating for a day) had a significant impact on nutritional status of children.

Protective role of selenium in the shortening of telomere length in newborns induced by in utero heavy metal exposure.

The effects of toxic heavy metals, such as arsenic (As), cadmium (Cd), and lead (Pb), on telomere length (TL) have been reported previously. Although selenium (Se) is considered as an anti-oxidant which may detoxify the effects, there are no data on whether Se could protect against the TL-shortening effects of heavy metals. Thus, the aim of this study was to evaluate the protective role of Se against heavy metal-induced TL shortening. A birth cohort study was conducted in Myanmar in 2016, including 408 mother-infant pairs. First, pregnant women in the third trimester were interviewed concerning their socioeconomic, and pregnancy and birth characteristics using a pre-validated questionnaire. Maternal spot urine samples were collected after the interview. During the follow-up period (1-3 months), blood samples were collected from the umbilical cord at birth by local health workers. Metal concentrations were measured using inductively coupled plasma mass spectrometry (ICP-MS). TL was measured by quantitative real-time polymerase chain reaction (PCR). Relative TL was calculated as the ratio of telomere genes to single-copy genes. To evaluate the effect of Se on TL shortening, molar ratios were calculated. Linear regression analyses were performed to examine the associations between heavy metals and TL, individually and after adjustment for Se level. The effects of As, Cd, and Pb exposure on TL were smaller after adjustment for the Se level, especially for Pb (unadjusted ß = -0.10; 95% CI: 0.18, -0.01; adjusted ß = -0.03; 95% CI: 0.13, 0.05). On stratifying the data by Se concentration, there was no significant association between Cd or Pb exposure and TL in the high-Se group. Our study indicated a protective effect of Se against the TL shortening induced by heavy metal exposure, where the effect sizes were smaller after adjusting for the Se level, compared to individual metal exposure.

In-utero arsenic exposure and growth of infants from birth to 6 months of age: a prospective cohort study in rural Bangladesh.

Arsenic exposure in postnatal life impacts the growth of children, but little is known about the effect of in-utero arsenic exposure on growth very early in childhood. The aim of this study was to examine the associations between in-utero arsenic exposure and the growth of infants from birth to 6 months of age using monthly follow-up data. A prospective cohort study was conducted in rural areas of Bangladesh with 108 mother-infant pairs. This study identified a negative association between in-utero arsenic exposure and head circumference of infants 1-6 months of age (coefficient = -1.20, 95% confidence interval [CI]: -1.97, -0.42), and the effect was more pronounced in the earlier ages of 1-3 months (coefficient = -0.88, 95% CI: -1.70, -0.05). Because head circumference is considered as a surrogate of brain size, our findings suggest that in-utero arsenic exposure influences brain growth during an important developmental period.

A systematic review of the prevalence and predictors of the double burden of malnutrition within households.

Recently, increasing attention has been paid to the emergence of the double burden of malnutrition within households. We provide an overview of the literature regarding this phenomenon by reviewing previous studies of the prevalence of double-burden households and associated factors together with the research methods used. Studies were identified from the electronic databases PubMed and Web of Science, using the same search terms for both. A total of thirty-five articles met the eligibility criteria, and 367 sets of prevalence data were extracted. In all, thirty-four articles were published in 2000 or later; twenty-four used secondary data and twenty-five focused on mother-child pairs. The ages of children varied from 0 to 19 years. All the studies used BMI as a nutritional indicator for adults. For children, height-for-age was most frequently used, whereas weight-for-age, weight-for-height and BMI-for-age were also used in multiple studies. The reported national prevalence of double-burden households varied from 0·0 to 26·8 % by country and year; however, few studies were directly comparable, because of differences in the combinations of undernourished and overweight persons, age ranges, nutritional indicators and cut-off points. Whereas many focused on African countries, a few involved Asian countries. Although urban residence, income and education were frequently assessed, the role of intermediate factors in nutritional status, such as diet and physical activity, remains unclear. It is recommended that future studies use comparable indicators and cut-off points, involve Asian countries, and investigate individual diet and physical activity.

Associations between neighborhood food environments and deficient protein intake among elderly people in a metropolitan suburb: A case study in Kisarazu city, Japan.

OBJECTIVES: Living in a poor food environment and its association with an increased risk of inadequate nutrient intake are increasingly important issues in Japan due to an increase in the elderly population. METHODS: The present study examined the relationships between neighborhood food environment and the protein and fat intakes of elderly Japanese individuals (n = 181) living in the metropolitan Tokyo suburb of Kisarazu. RESULTS: A logistic regression analysis adjusted for sociodemographic and shopping behavior variables revealed associations between subjectively evaluated poor neighborhood food environment and deficient protein intake. However, there was no significant association between excessive fat intake and neighborhood food environments. CONCLUSION: The findings demonstrate that living in a poor neighborhood food environment, which is becoming increasingly prevalent in Japan and other developed countries, has the potential to result in malnutrition, or at least in a low-quality diet, in elderly populations.

Association between sex inequality in animal protein intake and economic development in the Papua New Guinea highlands: The carbon and nitrogen isotopic composition of scalp hair and fingernail.

OBJECTIVES: People in the Papua New Guinea Highlands consume sweet potatoes as their dietary staple; consumption of animal protein is limited. In such societies with marginal protein intake, the intra-household allocation of animal protein in terms of sex or age is of importance. The objective of this study was to investigate how the allocation pattern of protein-rich foods by sex and age is associated with economic development in the Papua New Guinea Highlands. METHODS: The carbon and nitrogen isotopic compositions of fingernails, collected in 1995 in two areas (Tari and Port Moresby [the national capital where Tari migrants resided]), and of scalp hair, collected in 2007, 2012, and 2013 in three areas of different degree of economic development (Levani, Tari, and Goroka) were analyzed. RESULTS: Analysis of fingernail samples showed that δ(15)N was lower in rural communities than in the urban migrant community, while a sex difference in δ(15)N (higher in males than in females) was found in the former but not in the latter community. Age was not associated with either δ(15)N or δ(13)C values. The analysis of scalp hair samples showed that δ(15)N values were lowest in Levani, the least developed area. Furthermore, there were statistically significant sex differences in δ(15)N values in Levani but not in Tari and Goroka. Age was not associated with either δ(15)N or δ(13)C values. DISCUSSION: The sex inequality in animal protein consumption seems to have decreased as the communities in the Papua New Guinea Highlands have experienced economic development.

Reduced morning cortisol concentration in saliva was associated with obesity: Evidence from community-dwelling adults in papua new guinea.

OBJECTIVES: This study investigated morning salivary cortisol concentration in relation to total body fat composition among community-dwelling Papua New Guinean adults. METHODS: In addition to demographic and anthropometric measurements, saliva was collected in a single morning from 478 residents in Eastern Highlands Province and Madang Province. RESULTS: After adjusting for age, region, and occupation, the morning salivary cortisol concentration was significantly negatively correlated with body mass index among men (B = -0.01, P < 0.05) and women (B = -0.013, P < 0.05), and waist circumference (B = -0.007, P < 0.05), waist-to-hip-ratio (B = -1.214, P < 0.05), and subscapular-to-triceps skinfold-thickness ratio (B = -0.045, P < 0.05) among men. Men with total or abdominal body fat mass known for elevated risk of non-communicable diseases displayed lower cortisol compared to men without such risk. CONCLUSIONS: Papua New Guinean adults with increased accumulation of body fat showed reduced cortisol concentration in morning saliva. Am. J. Hum. Biol. 28:587-590, 2016. © 2016 Wiley Periodicals, Inc.

Medical Pluralism and Traditional/Complementary and Alternative Medicine Use Among Older People: a Cross-Sectional Study in a Rural Mountainous Village in Japan.

Given current concerns about the rapidly aging population in Japan, we investigated medical pluralism and health-seeking behaviors among individuals aged 50 years or older living in a rural mountain village in Japan. In total, 76 participants were interviewed about the methods they used to treat 11 common medical conditions. We found that all the respondents used at least two types of treatment for their medical conditions and nearly 90% used four or five types of treatment. The factors affecting health-seeking behaviors were age, education, car use, and the characteristics of the medical condition. Our results show that the older individuals in this community used both formal and traditional/complementary and alternative medicine (TM/CAM) treatments and did not view issues related to medical care as involving a dualistic choice between formal healthcare services and TM/CAM; however, the relationship between different types of TM/CAM and conventional healthcare varied.

Association of protein intakes and variation of diet-scalp hair nitrogen isotopic discrimination factor in Papua New Guinea highlanders.

OBJECTIVES: We present new nitrogen isotopic discrimination factor between diets and scalp hairs (Δ(15) NHair-Diet : δ(15) NHair - δ(15) NDiet ) for indigenous residents in three communities in the Papua New Guinea Highlands who consumed various amounts and qualities of protein. The Δ(15) N is important for precise evaluation of the dietary habits of human populations; in both contemporary and traditional lifestyles. Several hypotheses have been proposed regarding factors that affect Δ(15) N values, based largely on observations from animal feeding experiments. However, variations and factors controlling Δ(15) N in humans are not well understood, mainly due to the difficulty of controlling the diets of participants. MATERIALS AND METHODS: These residents were studied because they have maintained relatively traditional dietary habits, which allow quantitative recording of diets. Δ(15) N was estimated by comparing hair δ(15) N values to mean dietary δ(15) N values calculated from the recorded intake of each food item and their δ(15) N values. RESULTS: The results showed that: i) there was a significant difference in Δ(15) N among study locations (3.9 ± 0.9‰ for most urbanized, 5.2 ± 1.0‰ for medium and 5.0 ± 0.9‰ for least urbanized communities; range = 1.2-7.3‰ for all participants); and ii) estimated Δ(15) N values were negatively correlated with several indicators of animal protein intake (% nitrogen in diet: range = 0.9-7.6%). DISCUSSION: We hypothesize that a combination of several factors, which presumably included urea recycling and amino acid and protein recycling and/or de novo synthesis during metabolic processes, altered the Δ(15) N values of the participants.

Development, validation, and use of a semi-quantitative food frequency questionnaire for assessing protein intake in Papua New Guinean Highlanders.

OBJECTIVES: The aim of this article was to develop a semi-quantitative food frequency questionnaire (FFQ) and evaluate its validity to estimate habitual protein intake, and investigate current dietary protein intakes of Papua New Guinea (PNG) Highlanders. METHODS: A 32-item FFQ was developed and tested among 135 healthy male and female volunteers. The FFQ-estimated daily total and animal protein intakes were compared with biomarkers and 3-day Weighed Food Records (WFR) by correlation analyses, Bland-Altman plot analyses and joint classification analyses. RESULTS: The FFQ-estimated total protein intake significantly correlated with urinary nitrogen in the first morning void after adjusting urinary creatinine concentration (r = 0.28, P < 0.01) and the FFQ-estimated animal protein intake significantly correlated with the hair δ(15) N (Spearman's r = 0.34, P < 0.001). The limits of agreement were ±2.39 Z-score residuals for total protein intake and ±2.19 Z-score for animal protein intake, and intra-individual differences increased as protein intake increased. The classification into the same and adjacent quartiles was 66.0% for total protein intake and 73.6% for animal protein intake. Median daily total and animal protein intake estimates from the FFQ and the 3-day WFR showed a good agreement with differences of 0.2 and 4.9 g, respectively. None of the studied communities in the PNG Highlands met the biologically required protein intake; although the community closer to an urban center showed higher protein intake than the more remote communities. CONCLUSIONS: The newly developed 32-item FFQ for PNG Highlanders is applicable for evaluation of protein intake at the individual level. Am. J. Hum. Biol. 27:349-357, 2015. © 2014 Wiley Periodicals, Inc.

Spatio-temporal epidemiology of the cholera outbreak in Papua New Guinea, 2009-2011.

BACKGROUND: Cholera continues to be a devastating disease in many developing countries where inadequate safe water supply and poor sanitation facilitate spread. From July 2009 until late 2011 Papua New Guinea experienced the first outbreak of cholera recorded in the country, resulting in >15,500 cases and >500 deaths. METHODS: Using the national cholera database, we analysed the spatio-temporal distribution and clustering of the Papua New Guinea cholera outbreak. The Kulldorff space-time permutation scan statistic, contained in the software package SatScan v9.2 was used to describe the first 8 weeks of the outbreak in Morobe Province before cholera cases spread throughout other regions of the country. Data were aggregated at the provincial level to describe the spread of the disease to other affected provinces. RESULTS: Spatio-temporal and cluster analyses revealed that the outbreak was characterized by three distinct phases punctuated by explosive propagation of cases when the outbreak spread to a new region. The lack of road networks across most of Papua New Guinea is likely to have had a major influence on the slow spread of the disease during this outbreak. CONCLUSIONS: Identification of high risk areas and the likely mode of spread can guide government health authorities to formulate public health strategies to mitigate the spread of the disease through education campaigns, vaccination, increased surveillance in targeted areas and interventions to improve water, sanitation and hygiene.

Significant sex difference in the association between C-reactive protein concentration and anthropometry among 13- to 19-year olds, but not 6- to 12-year olds in Nepal.

Life history theory predicts a trade-off between immunostimulation and growth. Using a cross-sectional study design, this study aims to test the hypothesis that C-reactive protein (CRP) is negatively associated with height-for-age z-scores (HAZ scores) and BMI-for-age z-scores (BAZ scores) among 6- to 19-year olds (N = 426) residing in five Nepalese communities. Dried blood spot (DBS) samples were collected and assayed for CRP using an in-house enzyme immunoassay (EIA). Sex- and age-group-specific CRP quartiles were used to examine its association with growth in linear mixed-effects (LME) models. A significant difference was found in the proportion of elevated CRP (>2 mg/L, equivalent to ∼3.2 mg/L serum CRP) between 13- and 19-year-old boys (12%) and girls (4%). Concentrations of CRP were positively associated with HAZ score among adolescent (13-19 years) boys, which may indicate that individuals with greater energy resources have better growth and a better response to infections, thus eliminating the expected trade-off between body maintenance (immunostimulation) and growth. Adolescent boys with low BAZ and HAZ scores had low CRP values, suggesting that those who do not have enough energy for growth cannot increase their CRP level even when infected with pathogens. Among adolescent girls a positive association was observed between CRP and BAZ scores suggesting the possible effects of chronic low-grade inflammation due to body fat rather than infection. The association between CRP and growth was less evident among children (6-12 years) compared with adolescents, indicating that the elevated energy requirement needed for the adolescent growth spurt and puberty may play some role.

Epstein-Barr virus antibody titer and its association with the domain scores from the World Health Organization's Quality of Life questionnaire: Findings from Rural Hainan Province, China.

OBJECTIVE: Epstein-Barr virus (EBV) antibody titer has recently been used as a biomarker of psychological stress. This is the first study to investigate the association between EBV antibody titer and perceived quality of life (QOL) in Hainan Island, China. METHODS: Participants from two regions of Hainan Island, recruited into a larger study investigating the health impact of rapid economic development among rural residents, were stratified by age, sex, and region; 15 people were randomly selected from each of the 16 subgroups, to give a total sample size of 240. EBV antibody titer in dried blood spot samples was measured by enzyme-linked immunosorbent assay. The abbreviated version of the World Health Organization's Quality of Life questionnaire was used to gather information on six categories of QOL. Multiple linear regression analysis was used to examine the relationship between EBV antibody titer and QOL. RESULTS: After adjusting for the effects of age, sex, region and C-reactive protein concentration, EBV antibody titer was negatively associated with the physical (P = 0.044) and psychological QOL domains (P = 0.039). CONCLUSION: This study suggests that among individuals living in an environment in the initial stages of economic development EBV antibody titer, a biomarker of psychological stress, is not only associated with the psychological aspects of QOL but is also linked to physical problems.

Impact of lifestyle changes on stress in a modernizing rural population in Hainan Island, China.

OBJECTIVE: Little is known about inter-individual variation in psychological stress in modernizing rural populations in developing countries. The objective of this study was to investigate the association between Epstein-Barr virus (EBV) antibody titer, a biomarker of psychological stress, and lifestyle parameters in rural communities in Hainan Island, China. METHODS: EBV antibody titer was measured in dried blood spot (DBS) samples collected from 240 adults living in rural communities in Hainan Island. Measures of two major lifestyle changes in rural areas of Hainan Island, i.e., diet and commercial goods possession, were examined by using information on the weekly frequency of pork consumption and monthly mobile phone fees. Both parameters were standardized to create two composite scores: a total affluence index (TAI--the sum of these scores), and an investment tendency index (ITI--the difference between them). Least-squares regression analysis was used to investigate the association between EBV antibody titer and these lifestyle parameters. RESULTS: A positive association was found between the frequency f pork consumption and EBV antibody titer (P = 0.040), whereas a negative association was found between mobile phone fees and EBV antibody titer (P = 0.028). A negative association was also observed between ITI and EBV antibody titer (P = 0.002) after adjusting for the effect of TAI. CONCLUSION: Psychological stress among local residents was linked to the type of lifestyle changes they had experienced, where the adoption of a more market-oriented lifestyle, irrespective of current affluence, was associated with less psychological stress.