A recent study published in the Journal of Translational Internal Medicine (https://doi.org/10.1515/jtim-2024-0017) reveals significant insights into the broader impact of gastroesophageal reflux disease (GERD) on cardiovascular health. By using a rigorous bidirectional Mendelian randomization (MR) approach, the research provides compelling evidence that GERD-a condition traditionally recognized as a digestive disorder characterized by acid reflux and heartburn-may influence key cardiovascular risk factors, including blood pressure, lipid profiles, and heart disease risk.
This groundbreaking study suggests that GERD's effects may extend beyond the digestive system, potentially playing an important role in cardiovascular health. "Our research highlights that GERD may significantly impact cardiovascular risk, offering a more comprehensive view of its influence," said Qiang Wu, from the Senior Department of Cardiology at the Sixth Medical Center of the Chinese PLA General Hospital in Beijing, China.
The use of bidirectional Mendelian randomization provides an advantage over traditional studies by controlling for confounding factors and addressing reverse causality. This approach, which employs genetic data to make causal inferences, provides a stronger basis for understanding how GERD might influence cardiovascular outcomes. Genetic variants associated with GERD were used as instrumental variables, allowing researchers to investigate GERD's potential causal role in cardiovascular conditions with greater accuracy, according to Qiang Su, from the Department of Cardiology at Jiangbin Hospital of Guangxi Zhuang Autonomous Region. The study applied a two-sample MR approach, drawing data from genome-wide association studies (GWAS) involving more than 600,000 participants, including 129,000 diagnosed GERD cases, while cardiovascular data were obtained from a European cohort of over 200,000 individuals. The researchers focused on key blood pressure metrics such as systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and mean arterial pressure (MAP).
The study employed several advanced MR techniques, including Inverse Variance Weighted (IVW) analysis, MR Egger regression, and the Weighted Median approach. These methods controlled for pleiotropic effects, where one gene affects multiple traits, thereby enhancing the reliability of the findings. This rigorous approach led researchers to conclude that GERD could significantly impact cardiovascular risk factors, particularly blood pressure and lipid levels.
One of the study's most notable findings was a strong association between GERD and elevated blood pressure. The researchers observed that genetically predicted GERD was linked to higher systolic blood pressure (SBP) (β = 0.053, P = 0.036) and diastolic blood pressure (DBP) (β = 0.100, P < 0.001), suggesting that GERD could worsen hypertension-a major risk factor for heart disease and stroke.
In terms of lipid profiles, the study indicated that GERD was associated with increased levels of low-density lipoprotein (LDL) cholesterol (β = 0.093, P < 0.001) and triglycerides (β = 0.153, P < 0.001), both of which are associated with a higher risk of cardiovascular disease. Conversely, GERD was inversely associated with high-density lipoprotein (HDL) cholesterol (β = -0.115, P = 0.002), often considered the "good" cholesterol that protects against heart disease.
Moreover, the research showed that GERD elevates the risk of cardiovascular diseases such as myocardial infarction (heart attack) and hypertension. Specifically, the odds ratio for myocardial infarction was 1.272 (95% CI: 1.040 to 1.557, P = 0.019), and for hypertension, it was 1.357 (95% CI: 1.222 to 1.507, P < 0.001). However, no significant association was found between GERD and heart failure.
"These findings indicate that GERD may be a potential risk factor for cardiovascular diseases," said Qiang Su of Jiangbin Hospital. "By revealing these associations, our study underscores the importance of early diagnosis and prevention strategies for both GERD and cardiovascular conditions."
This study emphasizes the need for increased awareness of GERD's potential cardiovascular implications. With millions affected by GERD worldwide, these findings could encourage healthcare providers to adopt more proactive approaches for individuals at risk.
