Genetic Insights into Coronary Heart Disease in Mexico

Coronary Heart Disease (CHD) is a big problem around the world. It affects many people and causes many deaths. In 2021, it was responsible for about 9 million deaths, which is around 13% of all deaths globally. Even though improvements have been made in some countries, particularly in how we treat and prevent CHD, it still remains the top cause of death among adults. This is why preventing CHD is considered a priority in public health.

#Genetics and CHD

One interesting thing about CHD is that genetics plays a significant role. It's estimated that about 50% of the risk for developing CHD can be inherited. This means that if your family has a history of heart disease, you might be at a higher risk too. Some studies have shown that looking at genetic factors can help assess the risk of CHD even better than just considering traditional factors like blood pressure and cholesterol.

Polygenic Risk Scores (PRS) are tools that researchers have developed to combine the effects of many small genetic changes (known as single nucleotide polymorphisms or SNPs) into a single score that helps predict the likelihood of CHD. These scores have been found to identify individuals who are at greater risk of CHD, sometimes even more effectively than those with rare genetic conditions that have a strong impact on heart health.

#The Situation in Mexico

In Mexico, the number of deaths due to CHD for people aged 35 to 69 years has been on the rise. For example, from 1970 to 2020, the death rate in men increased from about 60 to 210 per 100,000, and in women, it went up from about 40 to 90 per 100,000. This increase is linked to a rise in common risk factors for CHD, particularly Obesity and Diabetes.

Despite the rising numbers, the effectiveness of PRS in predicting CHD risk in the Mexican population is uncertain. Most studies focusing on genetic risk for CHD have been conducted in European populations. Because only about 5% of participants in these studies are from non-European backgrounds, our understanding of PRS in places like Mexico is limited.

#A Study to Understand CHD Better

To explore this further, researchers conducted a study using data from the Mexico City Prospective Study (MCPS). This study aimed to evaluate how well existing PRS can predict CHD risk in Mexican adults who have high rates of obesity and diabetes.

#Study Design and Participants

The MCPS began between 1998 and 2004, where researchers visited households in two districts of Mexico City, inviting adults 35 years and older to participate. Out of over 112,000 households, about 95% agreed to join the study. Participants provided consent, and various health and lifestyle information was collected, along with blood samples for genetic analysis.

#Collecting Data

During household visits, trained nurses gathered information on various aspects of participants' lives, including their height, weight, and blood pressure. Participants also answered questions about their health history and lifestyle choices. Blood samples were taken for genetic analysis, allowing researchers to look at genetic variations linked to CHD.

#Understanding Polygenic Risk Scores

Researchers selected eight different PRS from existing studies to see how well they would work for predicting CHD in the Mexican population. Some of these scores were derived from European ancestry populations, while others considered multiple ancestries.

These PRS were then recalculated for each participant in the MCPS using their genetic data. The researchers examined how well these scores matched with the participants' genetic data and assessed their ability to predict CHD risk.

#Tracking Mortality

To see how many participants died from heart disease, researchers linked the study participants' names to Mexico City's official death registry. They confirmed that the death statistics were reliable, allowing for accurate tracking of cause-specific mortality.

#Analyzing the Results

The study looked at what is called “premature CHD,” which means either self-reported heart issues or deaths from CHD before the age of 80. Using statistical methods, researchers estimated the relationship between PRS and the likelihood of developing CHD. The analysis took into account various factors like age, sex, and other risk factors like education level, body measurements, blood pressure, and diabetes status.

#Overview of Findings

The researchers found that all eight PRS showed a positive trend with CHD risk. People with a higher genetic predisposition to CHD had significantly increased odds of developing heart problems. The results indicated that PRS with a higher number of genetic variations provided more robust predictions for CHD risk.

Among the PRS tested, one particular score had the strongest association with CHD risk, indicating that the genetic predisposition to heart disease is significant in this population. While all PRS were useful, those derived from multiple ancestries often had better predictive power than those based solely on European populations.

#Differences by Sex

Interestingly, the study found that men generally had a stronger genetic predisposition to CHD compared to women. For certain PRS, this difference was significant, possibly because scores with more SNPs were better at capturing the genetic risk in men.

#Sensitivity Analyses: Checking the Results

To ensure the accuracy of their results, researchers conducted several sensitivity analyses. They looked at different definitions of CHD and examined the findings across various demographic groups, including by age, education level, and other health factors. Overall, the results were consistent across different situations, affirming the findings.

#The Takeaway

This large-scale study highlighted the importance of understanding genetic predisposition to CHD in a population that has been previously underrepresented in such research. The results indicated that PRS can serve as a useful tool for predicting heart disease risk in Mexican adults, opening the door for improved heart health strategies.

However, it also pointed out that the current PRS do not capture all genetic factors at play within the Mexican population. More tailored approaches that consider unique genetic and environmental factors specific to this group could lead to even better predictions.

#The Need for More Research

Ultimately, this study underscores the need for increased focus on diverse populations in genetic research. Hispanics and other groups are often underrepresented in gene studies, which can lead to gaps in knowledge and tailored health care strategies. More research can help build a clearer picture of how genetics influences heart disease across different populations.

By using better tools and involving more diverse groups in research, we can improve how we assess and manage heart disease risk. After all, genetics is just one piece of the puzzle when it comes to heart health—lifestyle choices and environmental factors also play critical roles in our heart's well-being.

#Conclusion

In the battle against coronary heart disease, understanding genetic risks is important, but it is only part of the equation. With a better understanding of how genetic factors play out in different populations, we can tailor health interventions and improve outcomes for many. The future of heart health might just depend on how well we utilize this information, and who knows? With more studies, we might crack the code of heart disease prevention for everyone, turning down the volume on our hearts' ticking clocks!