Overall, Direct, Spillover, and Composite Effects of Components of a Peer-Driven Intervention Package on Injection Risk Behavior Among People Who Inject Drugs in the HPTN 037 Study

We sought to disentangle effects of the components of a peer-education intervention on self-reported injection risk behaviors among people who inject drugs (n = 560) in Philadelphia, US. We examined 226 egocentric groups/networks randomized to receive (or not) the intervention. Peer-education training consisted of two components delivered to the intervention network index individual only: (1) an initial training and (2) "booster" training sessions during 6- and 12-month follow up visits. In this secondary data analysis, using inverse-probability-weighted log-binomial mixed effects models, we estimated the effects of the components of the network-level peer-education intervention upon subsequent risk behaviors. This included contrasting outcome rates if a participant is a network member [non-index] under the network exposure versus under the network control condition (i.e., spillover effects). We found that compared to control networks, among intervention networks, the overall rates of injection risk behaviors were lower in both those recently exposed (i.e., at the prior visit) to a booster (rate ratio [95% confidence interval]: 0.61 [0.46-0.82]) and those not recently exposed to it (0.81 [0.67-0.98]). Only the boosters had statistically significant spillover effects (e.g., 0.59 [0.41-0.86] for recent exposure). Thus, both intervention components reduced injection risk behaviors with evidence of spillover effects for the boosters. Spillover should be assessed for an intervention that has an observable behavioral measure. Efforts to fully understand the impact of peer education should include routine evaluation of spillover effects. To maximize impact, boosters can be provided along with strategies to recruit especially committed peer educators and to increase attendance at trainings. Clinical Trials Registration Clinicaltrials.gov NCT00038688 June 5, 2002.

Factors associated with receiving results and attending colposcopy in patients with positive HPV screens in Mexico City

We identified patient and healthcare system factors related to receipt of screening results and attendance to colposcopy among patients with positive screening results in a cervical cancer screening program in Mexico City, Mexico. We analyzed data from 1,351 patients with high-risk human papillomavirus (HPV)-positive results from two screening demonstration studies conducted between 2017 and 2018. Factors associated with receipt of screening results and with adherence to a colposcopy appointment were identified using multivariable logistic regression. Participants had a median age of 40 years (IQR = 32-48), 60% had less than high school education, and 74% had a previous Pap screening in the last 5 years. Fifty-five percent of participants retrieved their screening results at the healthcare facility (HCF) without any reminder. Providing an email address for contact information, attending a HCF with family medicine, and receiving care from experienced nurses were associated with greater adherence to obtaining screening test results. Fifty-seven percent of participants attended their first scheduled colposcopy appointment. Providing a phone number improved adherence to colposcopy, whereas longer travel times between the HCF and the colposcopy clinic was associated with a decrease in colposcopy adherence. Having a Pap test in the last 5 years was positively associated with better compliance with both outcomes. Securing contact information may help to overcome barriers to future follow-up. Additional research is necessary on strategies for obtaining screening test results and scheduling appointments, which may help address barriers to access, such as limited staff availability, distance from the clinic, and travel costs.

Is aggregated surveillance data a reliable method for constructing tuberculosis care cascades? A secondary data analysis from Uganda

To accelerate tuberculosis (TB) control and elimination, reliable data is needed to improve the quality of TB care. We assessed agreement between a surveillance dataset routinely collected for Uganda's national TB program and a high-fidelity dataset collected from the same source documents for a research study from 32 health facilities in 2017 and 2019 for six measurements: 1) Smear-positive and 2) GeneXpert-positive diagnoses, 3) bacteriologically confirmed and 4) clinically diagnosed treatment initiations, and the number of people initiating TB treatment who were also 5) living with HIV or 6) taking antiretroviral therapy. We measured agreement as the average difference between the two methods, expressed as the average ratio of the surveillance counts to the research data counts, its 95% limits of agreement (LOA), and the concordance correlation coefficient. We used linear mixed models to investigate whether agreement changed over time or was associated with facility characteristics. We found good overall agreement with some variation in the expected facility-level agreement for the number of smear positive diagnoses (average ratio [95% LOA]: 1.04 [0.38-2.82]; CCC: 0.78), bacteriologically confirmed treatment initiations (1.07 [0.67-1.70]; 0.82), and people living with HIV (1.11 [0.51-2.41]; 0.82). Agreement was poor for Xpert positives, with surveillance data undercounting relative to research data (0.45 [0.099-2.07]; 0.36). Although surveillance data overcounted relative to research data for clinically diagnosed treatment initiations (1.52 [0.71-3.26]) and number of people taking antiretroviral therapy (1.71 [0.71-4.12]), their agreement as assessed by CCC was not poor (0.82 and 0.62, respectively). Average agreement was similar across study years for all six measurements, but facility-level agreement varied from year to year and was not explained by facility characteristics. In conclusion, the agreement of TB surveillance data with high-fidelity research data was highly variable across measurements and facilities. To advance the use of routine TB data as a quality improvement tool, future research should elucidate and address reasons for variability in its quality.

A Systematic Review and Meta-Analysis of Studies Evaluating the Effect of Medication Treatment for Opioid Use Disorder on Infectious Disease Outcomes

The opioid epidemic has fueled infectious disease epidemics. We determined the impact of medications for opioid use disorder (MOUD) on treatment outcomes of opioid use disorder (OUD)-associated infectious diseases: antiretroviral therapy (ART) adherence, human immunodeficiency virus (HIV) viral suppression, hepatitis C virus (HCV) sustained virologic response, HCV reinfection, new hepatitis B virus infections, and infectious endocarditis-related outcomes. Manuscripts reporting on these infectious disease outcomes in adults with OUD receiving MOUD compared with those with OUD "not" receiving MOUD were included. Initial search yielded 8169 papers; 9 were included in the final review. The meta-analysis revealed that MOUD was associated with greater ART adherence (odds ratio [OR] = 1.55; 95% confidence interval [CI] = 1.12-2.15) and HIV viral suppression (OR = 2.19; 95% CI = 1.88-2.56). One study suggested a positive association between MOUD and HCV sustained virologic response. There is significant support for integrating MOUD with HIV treatment to improve viral suppression among persons with HIV (PWH) and OUD. Treatment of OUD among PWH should be a priority to combat the opioid and HIV epidemics.

Timing of Antiretroviral Therapy Initiation and Risk of Cancer Among Persons Living With Human Immunodeficiency Virus

BACKGROUND

Persons living with human immunodeficiency virus (HIV; PLWH) experience a high burden of cancer. It remains unknown which cancer types are reduced in PLWH with earlier initiation of antiretroviral therapy (ART).

METHODS

We evaluated AIDS-free, ART-naive PLWH during 1996-2014 from 22 cohorts participating in the North American AIDS Cohort Collaboration on Research and Design. PLWH were followed from first observed CD4 of 350-500 cells/µL (baseline) until incident cancer, death, lost-to-follow-up, or December 2014. Outcomes included 6 cancer groups and 5 individual cancers that were confirmed by chart review or cancer registry linkage. We evaluated the effect of earlier (in the first 6 months after baseline) versus deferred ART initiation on cancer risk. Marginal structural models were used with inverse probability weighting to account for time-dependent confounding and informative right-censoring, with weights informed by subject's age, sex, cohort, baseline year, race/ethnicity, HIV transmission risk, smoking, viral hepatitis, CD4, and AIDS diagnoses.

RESULTS

Protective results for earlier ART were found for any cancer (adjusted hazard ratio [HR] 0.57; 95% confidence interval [CI], .37-.86), AIDS-defining cancers (HR 0.23; 95% CI, .11-.49), any virus-related cancer (HR 0.30; 95% CI, .16-.54), Kaposi sarcoma (HR 0.25; 95% CI, .10-.61), and non-Hodgkin lymphoma (HR 0.22; 95% CI, .06-.73). By 15 years, there was also an observed reduced risk with earlier ART for virus-related NADCs (0.6% vs 2.3%; adjusted risk difference -1.6; 95% CI, -2.8, -.5).

CONCLUSIONS

Earlier ART initiation has potential to reduce the burden of virus-related cancers in PLWH but not non-AIDS-defining cancers (NADCs) without known or suspected viral etiology.

Association of Immunosuppression and Human Immunodeficiency Virus (HIV) Viremia With Anal Cancer Risk in Persons Living With HIV in the United States and Canada

BACKGROUND

People living with human immunodeficiency virus (HIV; PLWH) have a markedly elevated anal cancer risk, largely due to loss of immunoregulatory control of oncogenic human papillomavirus infection. To better understand anal cancer development and prevention, we determined whether recent, past, cumulative, or nadir/peak CD4+ T-cell count (CD4) and/or HIV-1 RNA level (HIV RNA) best predict anal cancer risk.

METHODS

We studied 102 777 PLWH during 1996-2014 from 21 cohorts participating in the North American AIDS Cohort Collaboration on Research and Design. Using demographics-adjusted, cohort-stratified Cox models, we assessed associations between anal cancer risk and various time-updated CD4 and HIV RNA measures, including cumulative and nadir/peak measures during prespecified moving time windows. We compared models using the Akaike information criterion.

RESULTS

Cumulative and nadir/peak CD4 or HIV RNA measures from approximately 8.5 to 4.5 years in the past were generally better predictors for anal cancer risk than their corresponding more recent measures. However, the best model included CD4 nadir (ie, the lowest CD4) from approximately 8.5 years to 6 months in the past (hazard ratio [HR] for <50 vs ≥500 cells/µL, 13.4; 95% confidence interval [CI], 3.5-51.0) and proportion of time CD4 <200 cells/µL from approximately 8.5 to 4.5 years in the past (a cumulative measure; HR for 100% vs 0%, 3.1; 95% CI, 1.5-6.6).

CONCLUSIONS

Our results are consistent with anal cancer promotion by severe, prolonged HIV-induced immunosuppression. Nadir and cumulative CD4 may represent useful markers for identifying PLWH at higher anal cancer risk.

Smoking and Helicobacter pylori infection: an individual participant pooled analysis (Stomach Cancer Pooling- StoP Project)

Smoking has been associated with acquisition and increased persistence of Helicobacter pylori infection, as well as with lower effectiveness of its eradication. A greater prevalence of infection among smokers could contribute to the increased risk for gastric cancer. We aimed to estimate the association between smoking and seropositivity to H. pylori through an individual participant data pooled analysis using controls from 14 case-control studies participating in the Stomach Cancer Pooling Project. Summary odds ratios and prevalence ratios (PRs), adjusted for age, sex and social class, and the corresponding 95% confidence intervals (CIs) were estimated through random-effects meta-analysis. Heterogeneity was quantified using the I statistic and publication bias with Egger's test. There was no significant association between smoking (ever vs. never) and H. pylori seropositivity (adjusted odds ratio = 1.08; 95% CI: 0.89-1.32; adjusted PR = 1.01; 95% CI: 0.98-1.05). The strength of the association did not increase with the intensity or duration of smoking; stratified analyses according to sex, age, region or type of sample did not yield a consistent pattern of variation or statistically significant results, except for participants younger than 55 years and who had been smoking for more than 30 years (adjusted PR = 1.08; 95% CI: 1.02-1.15). This is the first collaborative analysis providing pooled estimates for the association between smoking and H. pylori seropositivity, based on detailed and uniform information and adjusting for major covariates. The results do not support an association between smoking and H. pylori infection.

Association of immunosuppression and HIV viraemia with non-Hodgkin lymphoma risk overall and by subtype in people living with HIV in Canada and the USA: a multicentre cohort study

BACKGROUND

Research is needed to better understand relations between immunosuppression and HIV viraemia and risk for non-Hodgkin lymphoma, a common cancer in people living with HIV. We aimed to identify key CD4 count and HIV RNA (viral load) predictors of risk for non-Hodgkin lymphoma, overall and by subtype.

METHODS

We studied people living with HIV during 1996-2014 from 21 Canadian and US cohorts participating in the North American AIDS Cohort Collaboration on Research and Design. To determine key independent predictors of risk for non-Hodgkin lymphoma, we assessed associations with time-updated recent, past, cumulative, and nadir or peak measures of CD4 count and viral load, using demographics-adjusted, cohort-stratified Cox models, and we compared models using Akaike's information criterion.

FINDINGS

Of 102 131 people living with HIV during the study period, 712 people developed non-Hodgkin lymphoma. The key independent predictors of risk for overall non-Hodgkin lymphoma were recent CD4 count (ie, lagged by 6 months; <50 cells per μL vs ≥500 cells per μL, hazard ratio [HR] 3·2, 95% CI 2·2-4·7) and average viral load during a 3-year window lagged by 6 months (a cumulative measure; ≥100 000 copies per mL vs ≤500 copies per mL, HR 9·6, 95% CI 6·5-14·0). These measures were also the key predictors of risk for diffuse large B-cell lymphoma (recent CD4 count <50 cells per μL vs ≥500 cells per μL, HR 2·4, 95% CI 1·4-4·2; average viral load ≥100 000 copies per mL vs ≤500 copies per mL, HR 7·5, 95% CI 4·5-12·7). However, recent CD4 count was the sole key predictor of risk for CNS non-Hodgkin lymphoma (<50 cells per μL vs ≥500 cells per μL, HR 426·3, 95% CI 58·1-3126·4), and proportion of time viral load was greater than 500 copies per mL during the 3-year window (a cumulative measure) was the sole key predictor for Burkitt lymphoma (100% vs 0%, HR 41·1, 95% CI 9·1-186·6).

INTERPRETATION

Both recent immunosuppression and prolonged HIV viraemia have important independent roles in the development of non-Hodgkin lymphoma, with likely subtype heterogeneity. Early and sustained antiretroviral therapy to decrease HIV replication, dampen B-cell activation, and restore overall immune function is crucial for preventing non-Hodgkin lymphoma.

FUNDING

National Institutes of Health, Centers for Disease Control and Prevention, US Agency for Healthcare Research and Quality, US Health Resources and Services Administration, Canadian Institutes of Health Research, Ontario Ministry of Health and Long Term Care, and the Government of Alberta.

Cancer risk in HIV-infected people in the USA from 1996 to 2012: a population-based, registry-linkage study

Background

Monitoring cancer risk among HIV-infected people in the modern antiretroviral therapy (ART) era is critical given their elevated risk for many cancers and prolonged survival with immunosuppression, ART exposure, and aging. Our study described cancer risk in HIV-infected people in the United States relative to the general population.

Methods

Utilizing data from linked population-based HIV and cancer registries (nine areas; 1996–2012), we calculated standardized incidence ratios (SIRs). We tested SIR differences by AIDS status and over time using Poisson regression.

Findings

Among 448,258 HIV-infected people, risk was elevated (p<0·0001) for cancer overall (SIR 1·69; 95%CI: 1·67–1·72), AIDS-defining cancers (Kaposi sarcoma [498; 478–519], non-Hodgkin lymphoma [11·5; 11·1–11·9], and cervix [3·24; 2·94–3·56]), most other virus-related cancers (e.g., anus [19·1; 18·1–20·0], liver [3·21; 3·02–3·41], and Hodgkin lymphoma [7·70; 7·20–8·23]), and some virus-unrelated cancers (e.g., lung [1·97; 1·89–2·05]), but not for other common cancers. Risk for several cancers was higher after AIDS onset and declined across calendar periods. After multivariable adjustment, SIRs decreased significantly across 1996–2012 for six cancers (Kaposi sarcoma, two non-Hodgkin lymphoma subtypes, anus, liver, and lung) but remained elevated in the latest period. SIRs did not increase over time for any cancer.

Interpretation

Risks for several virus-related cancers and lung cancer declined among HIV-infected people, likely reflecting ART expansion since 1996. Despite declines, risk for many cancers remain elevated in the modern treatment era.

Funding

National Cancer Institute.

Phthalate exposure, flavonoid consumption and breast cancer risk among Mexican women

OBJECTIVE

To evaluate if selected phthalate exposure and flavonoid intake interact on breast cancer (BC) risk.

MATERIAL AND METHODS

Interviews and urine samples were obtained from 233 women with histologically confirmed BC and 221 healthy controls matched by age and place of residence, from various states of northern Mexico. Urinary metabolites concentrations of diethyl phthalate (DEP), butyl benzyl phthalate (BBzP) and dioctyl phthalate (DOP) were determined by solid-phase extraction coupled with high-performance liquid chromatography/isotope dilution/tandem mass spectrometry. Using a semiquantitative food frequency questionnaire, consumption of five types of flavonoids (anthocyanidins, flavan-3-ols, flavanones, flavones and flavonols) was estimated according to three food groups: vegetables, fruits and legumes-oil seeds.

RESULTS

A higher intake of anthocyanidins and flavan-3-ols (from vegetables), synergistically increased the negative association between BBzP and BC. No other significant flavonoid-phthalate multiplicative interactions on the risk for BC were found.

CONCLUSION

The consumption of some flavonoids may interact with exposure to phthalates on the risk of BC. Epidemiological and underlying mechanisms information is still insufficient and requires further investigations.

Prevalence of non-HIV cancer risk factors in persons living with HIV/AIDS: a meta-analysis

OBJECTIVE

The burden of cancer among persons living with HIV/AIDS (PLWHA) is substantial and increasing. We assessed the prevalence of modifiable cancer risk factors among adult PLWHA in Western high-income countries since 2000.

DESIGN

Meta-analysis.

METHODS

We searched PubMed to identify articles published in 2011-2013 reporting prevalence of smoking, alcohol consumption, overweight/obesity, and infection with human papillomavirus (HPV), hepatitis C virus (HCV) and hepatitis B virus (HBV) among PLWHA. We conducted random effects meta-analyses of prevalence for each risk factor, including estimation of overall, sex-specific, and HIV-transmission-group-specific prevalence. We compared prevalence in PLWHA with published prevalence estimates in US adults.

RESULTS

The meta-analysis included 113 publications. Overall summary prevalence estimates were current smoking, 54% [95% confidence interval (CI) 49-59%] versus 20-23% in US adults; cervical high-risk HPV infection, 46% (95% CI 34-58%) versus 29% in US females; oral high-risk HPV infection, 16% (95% CI 10-23%) versus 4% in US adults; anal high-risk HPV infection (men who have sex with men), 68% (95% CI 57-79%), with no comparison estimate available; chronic HCV infection, 26% (95% CI 21-30%) versus 0.9% in US adults; and HBV infection, 5% (95% CI 4-5%) versus 0.3% in US adults. Overweight/obesity prevalence (53%; 95% CI 46-59%) was below that of US adults (68%). Meta-analysis of alcohol consumption prevalence was impeded by varying assessment methods. Overall, we observed considerable study heterogeneity in prevalence estimates.

CONCLUSION

Prevalence of smoking and oncogenic virus infections continues to be extraordinarily high among PLWHA, indicating a vital need for risk factor reduction efforts.

Dieta y cáncer gástrico en México y en el mundo

El cáncer gástrico (CG) es la cuarta causa de muerte por cáncer a nivel global. La dieta y el consumo de alcohol y tabaco, además de la infección por Helicobacter pylori determinan un gran número de casos de esta neoplasia. Algunos alimentos contienen sustancias que podrían influir en el proceso de carcinogénesis gástrica, aunque los mecanismos subyacentes no están completamente dilucidados. En México y el mundo, la disminución en el consumo de frutas, vegetales no feculentos y allium, leguminosas y alimentos fuente de selenio, así como el aumento en el consumo de sal, alimentos salados, salmuera y ahumados, chile, carnes procesadas y asadas o a la parrilla se han asociado respectivamente con un aumento de riesgo de CG. Con la evidencia disponible, se podrían desarrollar y evaluar programas para la prevención y control del CG.

Utilización correcta de las técnicas de detección de cáncer de mama en mujeres mexicanas

Objetivo. Identificar las características asociadas con la prevalencia de utilización correcta de la autoexploración manual (AE), el examen clínico (EC) y la mamografía (MA) para la detección de cáncer mamario (CaMa). Material y métodos. Se entrevistó a 1 030 mujeres mexicanas, sanas, de entre 20 y 88 años sobre su historia reproductiva y sociodemográfica. Con base en la forma y frecuencia de realización de estas técnicas de detección, se construyó un índice de utilización correcta. Resultados. La prevalencia de utilización correcta de la AE fue de 11% y del EC de 5.4%. El 7.6% de las mujeres entre 40 y 49 años y 31.6% de las mujeres con 50 años o más se realizaron una MA de acuerdo con la norma vigente al momento del estudio. El aseguramiento por parte del Instituto Mexicano del Seguro Social, del Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado o del Seguro Popular fue el principal determinante de la utilización de la MA. Conclusiones. Se evidencia la necesidad de incrementar la correcta utilización de la AE, el EC y la MA.

[Diet and gastric cancer in Mexico and in the world]

Gastric cancer (GC) is the fourth leading cause of cancer death at global level. Diet, alcohol and tobacco, in addition to Helicobacter pylori infection, account for a large number of cases. Some substances contained in foods may influence GC carcinogenesis process; however, the underlying mechanisms have not been fully elucidated. In Mexico and worldwide, a low intake of fruits, non-starchy and allium vegetables, pulses, and foods containing selenium, as well as high intake of salt, salty, salted and smoked foods, chili pepper, processed and grilled/barbecued meats, have been respectively associated with an increased risk of GC. Based on the available evidence, programs for GC prevention and control could be developed and evaluated.

[Correct utilization of breast cancer detection techniques in Mexican women]

OBJECTIVE

Identify the characteristics associated with correct utilization of self examination (SE), clinical exam (CE) and mammography (MA) for breast cancer (BC) early detection.

MATERIALS AND METHODS

Interviews were undertaken with 1 030 Mexican women (n=1 030), 20 to 88 years of age, regarding their reproductive and sociodemographic characteristics. An index of correct utilization was constructed based on the form and frequency practice of those techniques.

RESULTS

The prevalence of correct utilization of SE was 11% and 5.4% for CE. Further, 7.6% of women 40-49 years of age with 2 or more BC risk factors had MA during the two years prior to the interview, and for 31.6% among women ≥50 years of age the MA was annually. The main determinant of MA utilization was having financial protection from either IMSS, ISSSTE or Seguro Popular.

CONCLUSIONS

It is necessary to improve the correct utilization of BC detection techniques in Mexico.

PPARγ and PPARGC1B polymorphisms modify the association between phthalate metabolites and breast cancer risk

CONTEXT

Breast cancer (BC) risk has been differentially associated with urinary levels of some phthalate metabolites.

OBJECTIVE

To investigate whether PPARγ and PPARGC1B polymorphisms modulate these associations.

MATERIALS AND METHODS

208 BC cases were age-matched with 220 population controls. Phthalate metabolites were determined by HPLC-MS. PPARγ Pro12Ala (rs1801281) and PPARGC1B Ala203Pro (rs7732671) and Val279Ile (rs17572019) were genotyped.

RESULTS

The association between mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and BC risk was positively modified in PPARγ Pro12Ala C carriers. The association with mono-iso-butyl phthalate (MiBP) in PPARGC1B Ala203Pro G carriers was negatively modified.

CONCLUSION

PPARγ and PPARGC1B polymorphisms modulate the association between phthalate exposure and BC risk.

Arsenic exposure and calpain-10 polymorphisms impair the function of pancreatic beta-cells in humans: a pilot study of risk factors for T2DM

The incidence of type 2 diabetes mellitus (T2DM) is increasing worldwide and diverse environmental and genetic risk factors are well recognized. Single nucleotide polymorphisms (SNPs) in the calpain-10 gene (CAPN-10), which encodes a protein involved in the secretion and action of insulin, and chronic exposure to inorganic arsenic (iAs) through drinking water have been independently associated with an increase in the risk for T2DM. In the present work we evaluated if CAPN-10 SNPs and iAs exposure jointly contribute to the outcome of T2DM. Insulin secretion (beta-cell function) and insulin sensitivity were evaluated indirectly through validated indexes (HOMA2) in subjects with and without T2DM who have been exposed to a gradient of iAs in their drinking water in northern Mexico. The results were analyzed taking into account the presence of the risk factor SNPs SNP-43 and -44 in CAPN-10. Subjects with T2DM had significantly lower beta-cell function and insulin sensitivity. An inverse association was found between beta-cell function and iAs exposure, the association being more pronounced in subjects with T2DM. Subjects without T2DM who were carriers of the at-risk genotype SNP-43 or -44, also had significantly lower beta-cell function. The association of SNP-43 with beta-cell function was dependent on iAs exposure, age, gender and BMI, whereas the association with SNP-44 was independent of all of these factors. Chronic exposure to iAs seems to be a risk factor for T2DM in humans through the reduction of beta-cell function, with an enhanced effect seen in the presence of the at-risk genotype of SNP-43 in CAPN-10. Carriers of CAPN-10 SNP-44 have also shown reduced beta-cell function.

Capsaicin consumption, Helicobacter pylori CagA status and IL1B-31C>T genotypes: a host and environment interaction in gastric cancer

Gastric cancer (GC) has been associated with a complex combination of genetic and environmental factors. In contrast to most countries, available information on GC mortality trends showed a gradual increase in Mexico. Our aim was to explore potential interactions among dietary (chili pepper consumption), infectious (Helicobacter pylori) and genetic factors (IL1B-31 genotypes) on GC risk. The study was performed in three areas of Mexico, with different GC mortality rates. We included 158 GC patients and 317 clinical controls. Consumption of capsaicin (Cap), the pungent active substance of chili peppers, was estimated by food frequency questionnaire. H. pylori CagA status was assessed by ELISA, and IL1B-31 genotypes were determined by TaqMan assays and Pyrosequencing in DNA samples. Multivariate unconditional logistic regression was used to estimate potential interactions. Moderate to high Cap consumption synergistically increased GC risk in genetically susceptible individuals (IL1B-31C allele carriers) infected with the more virulent H. pylori (CagA+) strains. The combined presence of these factors might explain the absence of a decreasing trend for GC in Mexico. However, further research on gene-environment interactions is required to fully understand the factors determining GC patterns in susceptible populations, with the aim of recommending preventive measures for high risk individuals.

Phthalate exposure associated with self-reported diabetes among Mexican women

BACKGROUND

Phthalates are ubiquitous industrial chemicals used as plasticizers in plastics made of polyvinyl chloride (PVC) to confer flexibility and durability. They are also present in products used for personal-care, industry and in medical devices. Phthalates have been associated with several adverse health effects, and recently it has been proposed that exposure to phthalates, could have an effect on metabolic homeostasis. This exploratory cross-sectional study evaluated the possible association between phthalate exposure and self-reported diabetes among adult Mexican women.

METHODS

As part of an on-going case-control study for breast cancer, only controls were selected, which constituted 221 healthy women matched by age (±5 years) and place of residence with the cases. Women with diabetes were identified by self-report. Urinary concentrations of nine phthalate metabolites were measured by online solid phase extraction coupled to high performance liquid chromatography-isotope-dilution tandem mass spectrometry.

RESULTS

Participants with diabetes had significantly higher concentrations of di(2-ethylhexyl) pththalate (DEHP) metabolites: mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP) but lower levels of monobenzyl phthalate (MBzP) a metabolite of benzylbutyl phthalate, compared to participants without diabetes. A marginally significant positive associations with diabetes status were observed over tertiles with MEHHP (OR(T3 vs. T1)=2.66; 95% CI: 0.97-7.33; p for trend=0.063) and MEOHP (OR(T3 vs. T1)=2.27; 95% CI; 0.90-5.75; P for trend=0.079) even after adjusting for important confounders.

CONCLUSIONS

The results suggest that levels of some phthalates may play a role in the genesis of diabetes.

Personal care product use and urinary levels of phthalate metabolites in Mexican women

Sources of phthalates other than Polyvinyl chloride (PVC) related products are scarcely documented in Mexico. The objective of our study was to explore the association between urinary levels of nine phthalate metabolites and the use of personal care products. Subjects included 108 women who participated as controls in an ongoing population-based case-control study of environmental factors and genetic susceptibility to breast cancer in northern Mexico. Direct interviews were performed to inquire about sociodemographic characteristics, reproductive history, use of personal care products, and diet. Phthalate metabolites measured in urine by high performance liquid chromatography-isotope dilution tandem mass spectrometry were monoethyl phthalate (MEP), monobenzyl phthalate (MBzP), mono-n-butyl phthalate (MBP), mono-isobutyl phthalate (MiBP), mono-3-carboxypropyl phthalate (MCPP) as well as mono-2-ethylhexyl phthalate (MEHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), mono-2-ethyl-5-carboxypentyl phthalate (MECPP) that are metabolites of di-ethylhexyl phthalate (DEHP). Detectable urinary concentrations of phthalate metabolites varied from 75% (MEHP) to 100% (MEP, MBP, MEOHP, MEHHP and MECPP). Medians of urinary concentrations of some phthalate metabolites were significantly higher among users of the following personal care products compared to nonusers: body lotion (MEHHP, MECPP and sum of DEHP metabolites (ΣDEHP)), deodorant (MEHP and ΣDEHP), perfume (MiBP), anti-aging facial cream (MEP, MBP and MCPP) and bottled water (MCPP, MEHHP and MEOHP). Urinary concentrations of MEP showed a positive relationship with the number of personal care products used. Our results suggest that the use of some personal care products contributes to phthalate body burden that deserves attention due to its potential health impact.

Exposure to phthalates and breast cancer risk in northern Mexico

BACKGROUND

Phthalates, ubiquitous environmental pollutants that may disturb the endocrine system, are used primarily as plasticizers of polyvinyl chloride and as additives in consumer and personal care products.

OBJECTIVES

In this study, we examined the association between urinary concentrations of nine phthalate metabolites and breast cancer (BC) in Mexican women.

METHODS

We age-matched 233 BC cases to 221 women residing in northern Mexico. Sociodemographic and reproductive characteristics were obtained by direct interviews. Phthalates were determined in urine samples (collected pretreatment from the cases) by isotope dilution/high-performance liquid chromatography coupled to tandem mass spectrometry.

RESULTS

Phthalate metabolites were detected in at least 82% of women. The geometric mean concentrations of monoethyl phthalate (MEP) were higher in cases than in controls (169.58 vs. 106.78 microg/g creatinine). Controls showed significantly higher concentrations of mono-n-butyl phthalate, mono(2-ethyl-5-oxohexyl) phthalate, and mono(3-carboxypropyl) phthalate (MCPP) than did the cases. After adjusting for risk factors and other phthalates, MEP urinary concentrations were positively associated with BC [odds ratio (OR), highest vs. lowest tertile = 2.20; 95% confidence interval (CI), 1.33-3.63; p for trend < 0.01]. This association became stronger when estimated for premenopausal women (OR, highest vs. lowest tertile = 4.13; 95% CI, 1.60-10.70; p for trend < 0.01). In contrast, we observed significant negative associations for monobenzyl phthalate (MBzP) and MCPP.

CONCLUSIONS

We show for the first time that exposure to diethyl phthalate, the parent compound of MEP, may be associated with increased risk of BC, whereas exposure to the parent phthalates of MBzP and MCPP might be negatively associated. These findings require confirmation.

Dietary intake of polyphenols, nitrate and nitrite and gastric cancer risk in Mexico City

N-nitroso compounds (NOC) are potent animal carcinogens and potential human carcinogens. The primary source of exposure for most individuals may be endogenous formation, a process that can be inhibited by dietary polyphenols. To estimate the risk of gastric cancer (GC) in relation to the individual and combined consumption of polyphenols and NOC precursors (nitrate and nitrite), a population-based case-control study was carried out in Mexico City from 2004 to 2005 including 257 histologically confirmed GC cases and 478 controls. Intake of polyphenols, nitrate and nitrite were estimated using a food frequency questionnaire. High intakes of cinnamic acids, secoisolariciresinol and coumestrol were associated with an approximately 50% reduction in GC risk. A high intake of total nitrite as well as nitrate and nitrite from animal sources doubled the GC risk. Odds ratios around 2-fold were observed among individuals with both low intake of cinnamic acids, secoisolariciresinol or coumestrol and high intake of animal-derived nitrate or nitrite, compared to high intake of the polyphenols and low animal nitrate or nitrite intake, respectively. Results were similar for both the intestinal and diffuse types of GC. Our results show, for the first time, a protective effect for GC because of higher intake of cinnamic acids, secoisolariciresinol and coumestrol, and suggest that these polyphenols reduce GC risk through inhibition of endogenous nitrosation. The main sources of these polyphenols were pears, mangos and beans for cinnamic acids; beans, carrots and squash for secoisolariciresinol and legumes for coumestrol.