Effect modification by maximum temperature of the association between PM2.5 and short-term cardiorespiratory mortality and emergency room visits in Lima, Peru, 2010-2016.

BACKGROUND: The health effects of fine particulate matter (PM2.5) may be worse at higher temperatures. OBJECTIVE: To investigate temperature's effect on PM2.5-mortality/morbidity associations in Lima, Peru. METHODS: Time-series regressions relating PM2.5 and temperature to mortality and emergency room (ER) visits during 2010-2016. Daily PM2.5 levels (assigned to 40 Lima districts) and daily maximum temperature (Lima-wide) were estimated based on ground monitors, remote sensing, and modeling. We analyzed all-cause, cardiovascular (ICD codes I00-I99), and respiratory (ICD codes J00-J99) mortality, and cardiovascular and respiratory causes for ER visits. RESULTS: The average PM2.5 concentration was 20.9 µg/m3 (IQR 17.5-23.5). The mean daily maximum temperature was 23.8 °C (IQR 20.8-26.9). PM2.5's effect on all-cause, respiratory, and circulatory disease mortality was significantly (p < 0.05) stronger at temperatures above the maximum temperature median. The rate ratios per increase of 10 µg/m3 of PM2.5 for all cause, respiratory, and circulatory mortality respectively were 1.03 (1.00-1.06), 1.04 (0.98-1.10), and 1.04 (0.98-1.10) at temperatures below the median, vs. 1.08 (1.04-1.12), 1.11 (1.03-1.19), and 1.14 (1.05-1.25) when temperatures were above the median. Results were analogous for ER visits for respiratory but not circulatory disease. SIGNIFICANCE: Results strengthen the evidence that air pollution may be more dangerous when temperatures are higher. IMPACT: Our data contribute to a growing body of literature which indicates that the damaging effects of PM2.5 may be worse at higher temperature, adding new evidence from Lima, Peru.

Maternal serum level of manganese, single nucleotide polymorphisms, and risk of spontaneous preterm birth: A nested case-control study in China.

Manganese (Mn) is an essential trace element, but an excess or accumulation can be toxic. Until now, few studies have examined the effects of maternal Mn level on the risk of spontaneous preterm birth (SPB). The aims of this study were to examine the association between maternal Mn level and the risk of SPB at the early stage of pregnancy, and investigate whether this association was modified by single nucleotide polymorphisms (SNPs) in genes of superoxide dismutase (SOD) and catalase (CAT). We conducted a nested case-control study in three maternal and child health care hospitals in Shanxi province, China, from December 2009 to December 2013. From an overall cohort of 4229 women, 528 were included in our study, including 147 cases of SPB and 381 controls. Maternal blood samples were collected during 4-22 gestational weeks. The maternal serum concentrations of Mn was measured using inductively coupled plasma-mass spectrometry. We found the maternal Mn concentration in the case group (median: 1.55 ng/mL) was significantly higher than that in the control group (median: 1.27 ng/mL). Compared to the lowest level, the SPB risk was significantly increased to 1.44 (95%CI: 0.60-3.43), 2.42 (95%CI: 1.06-5.55) and 2.46 (95%CI: 1.08-5.62) respectively for the second, third and fourth quartiles in first trimester, but not significant in second trimester or overall. When exposure to a high Mn level, women who with AA (6.36, 95%CI: 1.57-25.71) and AG (3.04, 95%CI: 1.59-5.80) of rs2758352, with CC (2.34, 95%CI: 1.31-4.18) of rs699473, and with GG (2.26, 95%CI: 1.22-4.16) of rs769214 were more likely to develop a SPB, but not among women with other genotypes. In conclusion, high maternal serum Mn level is associated with the increased SPB risk in first trimester, and the association is modified by maternal SNPs of SOD2, SOD3 and CAT.

Brazilian Longitudinal Study of Adult Health (ELSA-Brasil): socio-occupational class as an effect modifier for the relationship between adiposity measures and self-rated health.

BACKGROUND: Little is known about the role of social class in the association between adiposity measures and self-rated health, and several studies have evaluated its influence as a confounder. The aim of the study is to investigate whether social class is an effect modifier in the association between adiposity measures and self-rated health in participants in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). METHOD: Cross-sectional design, including 6453 men and 7686 women. Body mass index (kg/m2) and waist circumference (cms) were assessed. Self-rated health was categorized as good, fair and poor. Socio-occupational class was based on the participants' occupation, education and per capita income. Multicovariate ordinal logistic model was used to evaluate the association between adiposity measures and self-rated health. RESULTS: For women, the low and medium socio-occupational class effects were higher for those with waist circumference between 80 and 88 cm or overweight. For men, the low and medium socio-occupational class effects were higher for those with adequate waist circumference or normal body mass index. CONCLUSIONS: Social class is an effect modifier in the association between body mass index or waist circumference and self-rated health.

Long-term exposure to ambient fine particles associated with asthma: A cross-sectional study among older adults in six low- and middle-income countries.

BACKGROUND: Ambient PM2.5 is considered harmful to the respiratory system. However, little has been shown about the long-term association between ambient PM2.5 and asthma. METHODS: A survey from 2007 to 2010 was conducted among adults over 50 years of age in six low- and middle- income countries (including China, India, Ghana, Mexico, Russia, and South Africa), which belonged to one part of a prospective cohort study - the Study on global AGEing and adult health. The yearly mean PM2.5 concentrations of the residential communities of participants were estimated from remote sensing data. A mixed effects model was applied to investigate the association between ambient PM2.5 and asthma. RESULTS: A total of 4553 asthma patients were identified among the 29,249 participants in this study, producing a prevalence of 15.57%. For each 10 µg/m3 increase in PM2.5, the adjusted prevalence ratio of asthma was 1.05 (95% Confidence Interval: 1.01, 1.08) after controlling for the effects of sex, age, BMI, education attainment, smoking status, alcohol consumption, and occupational exposure. Further analyses showed that males and smokers might be particularly vulnerable populations. Additionally, it was estimated that about 5.12% of the asthma cases in the study population (95% Confidence Interval: 1.44%, 9.23%) could be attributed to long-term PM2.5 exposure. CONCLUSION: Long-term exposure to PM2.5 might be an important risk factor of asthma. Effective air pollution reduction measures should be taken to reduce PM2.5 concentrations in order to reduce the associated asthma cases and disease burden.

Effect modification of FADS2 polymorphisms on the association between breastfeeding and intelligence: results from a collaborative meta-analysis.

BACKGROUND: Accumulating evidence suggests that breastfeeding benefits children's intelligence, possibly due to long-chain polyunsaturated fatty acids (LC-PUFAs) present in breast milk. Under a nutritional adequacy hypothesis, an interaction between breastfeeding and genetic variants associated with endogenous LC-PUFAs synthesis might be expected. However, the literature on this topic is controversial. METHODS: We investigated this gene × environment interaction through a collaborative effort. The primary analysis involved >12 000 individuals and used ever breastfeeding, FADS2 polymorphisms rs174575 and rs1535 coded assuming a recessive effect of the G allele, and intelligence quotient (IQ) in Z scores. RESULTS: There was no strong evidence of interaction, with pooled covariate-adjusted interaction coefficients (i.e. difference between genetic groups of the difference in IQ Z scores comparing ever with never breastfed individuals) of 0.12[(95% confidence interval (CI): -0.19; 0.43] and 0.06 (95% CI: -0.16; 0.27) for the rs174575 and rs1535 variants, respectively. Secondary analyses corroborated these results. In studies with ≥5.85 and <5.85 months of breastfeeding duration, pooled estimates for the rs174575 variant were 0.50 (95% CI: -0.06; 1.06) and 0.14 (95% CI: -0.10; 0.38), respectively, and 0.27 (95% CI: -0.28; 0.82) and -0.01 (95% CI: -0.19; 0.16) for the rs1535 variant. CONCLUSIONS: Our findings did not support an interaction between ever breastfeeding and FADS2 polymorphisms. However, subgroup analysis suggested that breastfeeding may supply LC-PUFAs requirements for cognitive development if breastfeeding lasts for some (currently unknown) time. Future studies in large individual-level datasets would allow properly powered subgroup analyses and further improve our understanding on the breastfeeding × FADS2 interaction.

The role of city income inequality, sex ratio and youth mortality rates in the effect of violent victimization on health-risk behaviors in Brazilian adolescents.

This study integrates insights from evolutionary psychology and social epidemiology to present a novel approach to contextual effects on health-risk behaviors (unprotected sex, drunkenness episodes, drugs and tobacco experimentation) among adolescents. Using data from the 2012 Brazilian National Survey of Adolescent Health (PeNSE), we first analyzed the effects of self-reported violent victimization on health-risk behaviors of 47,371 adolescents aged 10-19 nested in the 26 Brazilian state capitals and the Federal District. We then explored whether the magnitude of these associations was correlated with cues of environmental harshness and unpredictability (youth external mortality and income inequality) and mating competition (sex ratio) from the city level. Results indicated that self-reported violent victimization is associated with an increased chance of engagement in health-risk behaviors in all Brazilian state capitals, for both males and females, but the magnitude of these associations varies in relation to broader environmental factors, such as the cities' age-specific mortality rates, and specifically for females, income inequality and sex ratio. In addition to introducing a novel theoretical and empirical approach to contextual effects on adolescent health-risk behaviors, our findings reinforce the need to consider synergies between people's life experiences and the conditions where they live, when studying health-risk behaviors in adolescence.

ASSOCIATION OF TOTAL AND DIFFERENTIAL WHITE BLOOD CELL COUNTS TO DEVELOPMENT OF TYPE 2 DIABETES IN MEXICAN AMERICANS IN CAMERON COUNTY HISPANIC COHORT.

OBJECTIVE: To evaluate the relationship between total and differential White Blood Cell (WBC) counts with time to transition to type 2 diabetes in Mexican Americans using prospective data from the Cameron County Hispanic Cohort (CCHC). RESULTS: Multivariable Cox proportional hazards regression models revealed that obese Mexican-American cohort participants whose total WBC or granulocyte count increased over time had 1.39 and 1.35 times higher risk respectively of transition to type 2 diabetes when compared to overweight participants. The granulocyte or total WBC count in participants with BMI≥35 were significant risk factors for transition to type 2 diabetes. CONCLUSIONS: Increased total WBC and WBC differential counts, particularly lymphocytes and granulocytes, are associated with risk of transition to type 2 diabetes in obese Mexican Americans, after adjusting for other potential confounders. Screening and monitoring the WBC counts, including lymphocytes and granulocytes can help with monitoring potential transition to type 2 diabetes.

A growing role for gender analysis in air pollution epidemiology / O papel crescente, na epidemiologia da poluição do ar, da análise relacionada ao sexo da pessoa exposta

Epidemiologic studies of air pollution effects on respiratory health report significant modification by sex, although results are not uniform. Importantly, it remains unclear whether modifications are attributable to socially derived gendered exposures, to sex-linked physiological differences, or to some interplay thereof. Gender analysis, which aims to disaggregate social from biological differences between males and females, may help to elucidate these possible sources of effect modification. Studies of children suggest stronger effects among boys in early life and among girls in later childhood. The qualitative review describes possible sources of difference in air pollution response between women and men, which may vary by life stage, coexposures, hormonal status, or other factors. The sources of observed effect modifications remain unclear, although gender analytic approaches may help to disentangle gender and sex differences in pollution response. A framework for incorporating gender analysis into environmental epidemiology is offered, along with several potentially useful methods from gender analysis.

Embora sem uniformidade nos resultados, os estudos epidemiológicos dos efeitos da poluição do ar sobre a saúde respiratória relatam variações significativas em função do sexo da pessoa exposta à poluição. Vários estudos sobre adultos relatam efeitos mais severos entre mulheres, particularmente entre as de idade avançada, tais efeitos também estando presentes quando se faz uma avaliação da exposição a um ambiente residencial. Os estudos de crianças sugerem efeitos mais severos na infância de meninos, assim como na pré-adolescência de meninas. A variação na resposta à poluição do ar pode ser uma função quer do estágio vital da pessoa exposta, quer da sua exposição simultânea a fatores diversos, quer do estado hormonal da pessoa em questão ou de outros fatores. As fontes das variações observadas nos efeitos ainda não estão claras, mas as abordagens analíticas relacionadas ao sexo da pessoa exposta poderão ajudar a desemaranhar as diferenças observadas, na resposta à poluição, sujeitas à influência do gênero da pessoa exposta. Apresentamos, aqui, um trabalho estrutural, com o propósito de se passar a incorporar, na epidemiologia ambiental, uma análise em relação ao sexo da pessoa exposta, juntamente com diversos métodos de utilidade potencial a partir da análise relacionada ao sexo da pessoa exposta.