Distribution of triglyceride-rich lipoproteins and their remnants and their contribution to cardiovascular risk in the Mexican population.

BACKGROUND AND AIMS: In recent years, scientific interest in triglyceride-rich lipoproteins (TRL) and remnant cholesterol has increased, focusing on the evidence that these lipoproteins are a causal factor for developing atherosclerotic cardiovascular disease (ASCVD). Furthermore, a high remnant concentration (>38 mg/dL) has been associated with several non-cardiovascular risks. We aimed in this study to describe the percentile distribution of remnant cholesterol. Additionally, we evaluated the association between remnant cholesterol plasma concentration and epidemiologically relevant cardio-metabolic outcomes such as hypertension, type 2 diabetes (T2D), and ASCVD. METHODS: We analyzed data from 9,591 adults from the National Survey of Health and Nutrition (ENSANUT) 2018 with fasting blood samples and complete medical history questionnaires. We built multivariate models to evaluate the association between chronic diseases and blood remnant concentration. To compare our 2018-sub-sample against a population reference, we used the NHANES (2005-2014) publicly available datasets by ethnicity. RESULTS: Remnants were independently associated with cardiovascular risk, diabetes, hypertension, obesity, and metabolic syndrome. For all outcomes, the blood remnant concentration was a stronger predictor than LDL. At all deciles, the blood remnant concentration was higher in ENSANUT-2018. CONCLUSIONS: A remnant blood concentration above 38 mg/dL was highly prevalent among Mexicans. Remnants were significantly associated with a higher risk of diabetes, hypertension, obesity, and cardiovascular risk. This association occurred independently of other lipid markers.

Trends in the mortality of diabetes in Mexico from 1998 to 2022: a joinpoint regression and age-period-cohort effect analysis.

OBJECTIVE: The purpose was to analyze age-standardized trends in diabetes mortality rates (DMR) from 1998 to 2022, stratified by sex and Mexican state, and the effects attributable to age, period, and cohort by sex. STUDY DESIGN: Joinpoint regression and age-period-cohort effect analysis. METHODS: Based on the tenth revision of the International Classification of Diseases, E11, E12, E13, and E14 codes of the death certificate, a daily record of mortality was extracted from the death certificate attributable to diabetes as the main cause. From 1998 to 2022, sexes and ages (≥20 years) were used to calculate the crude mortality rates and standardized at the national and Mexican state levels. Additionally, the age-period-cohort model was used to examine age, period, and cohort effects. RESULTS: From 1998 to 2005, the age-adjusted DMR increased by 3.6% (95% confidence interval [CI]: 2.7, 4.5) for the total population, as shown by the joinpoint regression analysis at a national level; from 2017 to 2020, it increased by 7.4% (95% CI: 0.6, 14.8). The DMR with the highest increase during the study period came mainly from states in the country's southeastern region, 2.3% to 3.7% per year. The net age and period effects showed that mortality increased with advancing age and with going time, respectively; and the net cohort effect revealed that mortality increased in more recent birth cohorts, mainly in men Rate Ratio (RR) = 2.37 (95% CI: 2.29, 2.46) vs RR = 1.13 (95% CI: 1.09, 1.17). CONCLUSION: The DMR increased among older age groups. The period effect showed that mortality increased over time. Furthermore, the cohort effect showed that mortality increased in more recent birth cohorts, especially among men.

Prenatal exposure to metals modified DNA methylation and the expression of antioxidant- and DNA defense-related genes in newborns in an urban area.

The developmental period in utero is a critical window for environmental exposure. Epigenetic fetal programming via DNA methylation is a pathway through which metal exposure influences the risk of developing diseases later in life. Genetic damage repair can be modified by alterations in DNA methylation, which, in turn, may modulate gene expression due to metal exposure. We investigated the impact of prenatal metal exposure on global and gene-specific DNA methylation and mRNA expression in 181 umbilical cord blood samples from newborns in Mexico City. Global (LINE1) and promoter methylation of DNA-repair (OGG1 and PARP1) and antioxidant (Nrf2) genes was evaluated by pyrosequencing. Prenatal metal exposure (As, Cu, Hg, Mn, Mo, Pb, Se, and Zn) was determined by ICP-MS analysis of maternal urine samples. Multiple regression analyses revealed that DNA methylation of LINE1, Nrf2, OGG1, and PARP1 was associated with potentially toxic (As, Hg, Mn, Mo, and Pb) and essential (Cu, Se, and Zn) elements, and with their interactions. We also evaluated the association between gene expression (mRNA levels quantified by p-PCR) and DNA methylation. An increase in OGG1 methylation at all sites and at CpG2, CpG3, and CpG4 sites was associated with reduced mRNA levels; likewise, methylation at the CpG5, CpG8, and CpG11 sites of PARP1 was associated with reduced mRNA expression. In contrast, methylation at the PARP1 CpG7 site was positively associated with its mRNA levels. No associations between Nrf2 expression and CpG site methylation were observed. Our data suggest that DNA methylation can be influenced by prenatal metal exposure, which may contribute to alterations in the expression of repair genes, and therefore, result in a lower capacity for DNA damage repair in newborns.

Verbal Memory and Learning in Schoolchildren Exposed to Manganese in Mexico.

Manganese (Mn) is an essential nutrient for cellular function, but in high concentrations, it is neurotoxic. Environmental exposure to Mn has been associated with cognitive effects in children. This study aimed to assess the effect of environmental exposure to Mn on verbal memory and learning in schoolchildren residents from two municipalities in the state of Hidalgo, Mexico. Cross-sectional studies were conducted in 2006 and 2013 with a total of 265 schoolchildren of 7 to 11 years old. Children's Auditory Verbal Learning Test-2 (CAVLT-2) was used to assess verbal memory and learning. Mn exposure tertiles were defined according to hair manganese (MnH) levels determined by atomic absorption spectrophotometry. Linear regression models were used to estimate the association between MnH levels and CAVLT-2 scores. The models were adjusted by potential confounders. The lowest and highest exposure tertiles were defined below and above MnH levels of ≤ 0.72 and ≥ 3.96 µg/g, respectively. Mn exposure was significantly associated with an average of 5- to 9-point decrease in learning curves and summary CAVLT-2 scores in the highest tertile. This study adds to the evidence of decreased verbal memory and learning in schoolchildren environmentally exposed to manganese.

Effect of omega-3 fatty acids supplementation during pregnancy on lung function in preschoolers: a clinical trial.

RATIONALE: Prenatal omega-3 fatty acids improve alveolarization, diminish inflammation, and improve pulmonary growth, but it is unclear whether these outcomes translate into improved postnatal lung function. OBJECTIVE: We assessed the effect of prenatal supplementation with docosahexaenoic acid (DHA) on offspring lung function through 60 months of age. METHODS: We included a cohort of 772 Mexican preschoolers whose mothers participated in a clinical trial (NCT00646360) of supplementation with DHA or a placebo from week 18-22 of gestation through delivery. MEASUREMENTS: The children were followed after birth and anthropometric measurements and forced oscillation tests were performed at 36, 48, and 60 months of age. The effect of DHA was tested using a longitudinal mixed effect models. RESULTS: Overall, mean (Standard Deviation) of the measurements of respiratory system resistance and respiratory system reactance at 6, 8, and 10 Hz during follow up period were 11.3 (2.4), 11.1 (2.4), 10.3 (2.2) and -5.2 (1.6), -4.8 (1.7), -4.6 (1.6), respectively. There were no significant differences in pulmonary function by treatment group. DHA did not affect the average lung function or the trajectories through 60 months. CONCLUSIONS: Prenatal DHA supplementation did not influence pulmonary function in this cohort of Mexican preschoolers.

Effects of manganese exposure on visuoperception and visual memory in schoolchildren.

BACKGROUND: Manganese (Mn) is an essential metal involved in multiple physiological functions. Environmental exposure to airborne Mn is associated with neurocognitive deficits in humans. Children, whose nervous system is in development, are particularly susceptible to Mn neurotoxicity. OBJECTIVE: The objective of this study was to assess the association between Mn environmental exposure, and effects on visuoperception and visual memory in schoolchildren. METHODS: We assessed schoolchildren between 7 and 11 years old, with similar socioeconomic status, from the mining district of Molango (n=148) and Agua Blanca (n=119, non-mining area) in Hidalgo state, Mexico. The Rey-Osterrieth Complex Figure (ROCF) test was used to assess visuoperception and short-term visual memory. Hair manganese (MnH) concentrations were determined. Linear regression models were constructed to estimate the associations between MnH and ROCF scores, adjusted for potential confounders. RESULTS: The geometric mean MnH was nine times higher in schoolchildren from the Mn mining area (5.25µg/g) than in schoolchildren from the non-mining area (0.55µg/g). For the ROCF Copy trial, MnH was significantly associated with an increase in distortion errors (tangency, closure), angle errors, overtracing (partial overtracing). In the Immediate Recall trial, MnH was significantly associated with increased overtracing (partial overtracing) and omissions, and negatively associated with the number of perceptual drawn units, total score and percentage immediate recall. CONCLUSIONS: MnH is associated with alterations in visuoperception and short-term visual memory in schoolchildren exposed to airborne Mn.