Our study can offer new insights into disease mechanisms and prevention through the analysis of risk factor information in a large sample of Mexicans.

Background Vigilant management of women with high-risk human papillomavirus (hrHPV) is necessary in cancer screening programs. To this end, we evaluated the performance of S5 (targeting DNA methylation in HPV16, HPV18, HPV31, HPV33, and human gene EPB41L3) to predict cervical intraepithelial neoplasia grade 2 or higher (CIN2+) in a sample of hrHPV-infected women referred to colposcopy in the FRIDA Study, a large screening trial in Mexico. A nested case-control sample with women referred to colposcopy either by atypical squamous cells of undetermined significance or higher (ASCUS+) in cytology and/or positive for HPV types 16 or 18 was tested by S5. Seventy-nine cases of CIN2+ were age-matched to 237 controls without a diagnosis of CIN2+ (<CIN2). DNA from exfoliated cervical cells was bisulfite converted and PCR amplified for S5 targets, and methylation was quantified at specific cytosines by pyrosequencing. Results The S5 classifier separated women with CIN2+ from <CIN2 with a highly significant area under the curve (AUC) of 0.75 (95% CI 0.69–0.82), while AUC for CIN3+ was 0.81 (95% CI 0.74–0.89). To optimize sensitivity and specificity for Mexico, an alternative S5 cutoff of 3.7 was implemented to account for overall higher methylation seen in our already triaged women. All three invasive cancers were detected by methylation or HPV16/18 but none by cytology. Sensitivity of S5 for CIN2+ was 62% (95% CI 50.4–72.7%), specificity was 73% (95% CI 66.9–78.5%), and adjusted PPV was 15.1% (95% CI 12.0–18.3%). In contrast, the crude sensitivity of HPV16/18 detection and cytology were 63.3% (95% CI 51.7–73.9%) and 57.0% (95% CI 45.3–68.1%) respectively; specificity was 29.1% (95% CI 23.4–35.3%) and 62.4% (95% CI 55.9–68.6%) respectively, while adjusted PPV was 6.4% (95% CI 4.9–8.1%) and 10.5% (95% CI 8.0–13.1%), respectively. Methylation testing could reduce colposcopy referrals by 30 to 50% with virtually no loss of sensitivity for CIN2+ and CIN3+. Conclusions S5 testing on hrHPV-positive women significantly increased diagnostic information compared to triage by HPV16/18 plus cytology and appears to have clinical utility as an additional test to substantially lessen burdens on colposcopy. Trial registration The FRIDA Study is registered in ClinicalTrials.gov, number NCT02510027.

Objective To examine changes in categories of soft drink consumption in a cohort of Mexican adults, three years after the implementation of the sugar sweetened beverage tax. Design Open cohort longitudinal analysis. Setting Three waves of the Health Workers Cohort Study, Mexico, spanning 2004 to 2018. Participants 1770 people aged 19 years or older with information on drinks consumption available in at least one of the three cohort waves. Main outcome measure Change in probability of belonging to one of four categories of soft drinks consumption (non, low, medium, high) after the tax was implemented. Heterogeneity of associations by income and education was also assessed. Results Before the implementation of the tax, more than 50% of the participants were medium and high consumers of soft drinks and less than 10% were in the non-consumer category. After the tax was implemented, 43% of the population was categorised as medium or high consumers and the prevalence of non-consumers increased to 14%. Three years after implementation of the tax on 1 January 2014, the probability of being a non-consumer of soft drinks increased by 4.7 (95% confidence interval 0.3 to 9.1) percentage points and that of being a low consumer increased by 8.3 (0.6 to 16.0) percentage points compared with the pre-tax period. Conversely, the probability of being in the medium and high levels of soft drinks consumption decreased by 6.8 (0.5 to 13.2) percentage points and 6.1 (0.4 to 11.9) percentage points, respectively. No significant heterogeneity of the tax across income levels was observed, but stronger effects of the tax were seen in participants with secondary school education or higher, compared with those with elementary school or less. Conclusions The Mexican sugar sweetened beverage tax was associated with a reduction in the probability of consuming soft drinks in this cohort of employees from a healthcare provider. The results cannot be extrapolated to the Mexican population, but they suggest that three years after implementation, the tax had helped to increase the proportion of people who do not consume soft drinks while decreasing the proportion of high and medium consumers.

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Non-alcoholic fatty liver disease (NAFLD) is the accumulation of extra fat in liver cells not caused by alcohol. Elevated transaminase levels are common indicators of liver disease, including NAFLD. Previously, we demonstrated that PNPLA3 (rs738409), LYPLAL1 (rs12137855), PPP1R3B (rs4240624), and GCKR (rs780094) are associated with elevated transaminase levels in overweight/obese Mexican adults. We investigated the association between 288 SNPs identified in genome-wide association studies and risk of elevated transaminase levels in an admixed Mexican-Mestizo sample of 178 cases of NAFLD and 454 healthy controls. The rs2896019, rs12483959, and rs3810622 SNPs in PNPLA3 and rs1227756 in COL13A1 were associated with elevated alanine aminotransferase (ALT, ≥40 IU/L). A polygenic risk score (PRS) based on six SNPs in the ADIPOQ, COL13A1, PNPLA3, and SAMM50 genes was also associated with elevated ALT. Individuals carrying 9–12 risk alleles had 65.8% and 48.5% higher ALT and aspartate aminotransferase (AST) levels, respectively, than those with 1–4 risk alleles. The PRS showed the greatest risk of elevated ALT levels, with a higher level of significance than the individual variants. Our findings suggest a significant association between variants in COL13A1, ADIPOQ, SAMM50, and PNPLA3, and risk of NAFLD/elevated transaminase levels in Mexican adults with an admixed ancestry. This is the first study to examine high-density single nucleotide screening for genetic variations in a Mexican-Mestizo population. The extent of the effect of these variations on the development and progression of NAFLD in Latino populations requires further analysis.