Researchers from the Cleveland Clinic and Tufts University have uncovered that high levels of trimethylamine N-oxide (TMAO) may be a significant predictor of chronic kidney disease (CKD). By identifying TMAO as a potential predictive biomarker, this study paves the way for earlier detection and targeted interventions to mitigate the burden of CKD. Learn more with this recap of the study.
Chronic kidney disease (CKD) poses a substantial health burden globally, affecting millions of individuals and often progressing silently until advanced stages. That’s why identifying biomarkers that can signal the onset or progression of CKD is paramount for timely intervention and improved patient outcomes.
One potential biomarker is trimethylamine N-oxide (TMAO). TMAO is a gut microbiota-derived metabolite that accumulates in CKD due to impaired renal clearance. Its pro-inflammatory and pro-fibrotic effects may contribute to the development and progression of CKD, making it a potential biomarker according to recent research.
How the Study Was Designed
In a groundbreaking study, researchers from the Cleveland Clinic and Tufts University have uncovered a significant predictor of CKD: high blood levels of TMAO.
The study delved into the association between TMAO levels and the risk of developing CKD over time. Leveraging data from large-scale population cohorts, the team meticulously analyzed blood samples and clinical data from thousands of participants, tracking their health outcomes over an extended period.
The study involved 10,564 participants from two community-based cohorts with baseline estimated glomerular filtration rate (eGFR) greater than or equal to 60 mL/min/1.73m². TMAO levels were measured using targeted mass spectrometry at baseline and follow-up, with creatinine and cystatin C used to compute eGFR up to 4 times during follow-up. Incident CKD was defined as eGFR decline greater than or equal to 30 percent from baseline with resulting eGFR<60 ml/min/1.73 m².
Time-varying Cox models adjusted for various factors assessed the association of serial TMAO measures with incident CKD, while linear mixed models analyzed the association with annualized eGFR change.
What the Study Found
Over a median follow-up of 9.4 years, 979 incident CKD events occurred. Higher TMAO levels were associated with an increased risk of incident CKD and greater annualized eGFR decline, exhibiting a monotonic dose-response relationship across quintiles. These associations were consistent across racial/ethnic groups examined and comparable to or larger than those observed for established CKD risk factors, such as diabetes, systolic blood pressure, age, and race.
It’s also important to note that the mechanisms underlying the association between TMAO and CKD are multifaceted. Elevated TMAO levels have been linked to systemic inflammation, endothelial dysfunction, and oxidative stress, all of which contribute to the pathogenesis of kidney damage. Furthermore, TMAO may exacerbate renal injury by promoting the deposition of harmful substances within the kidneys and impairing renal function over time.
And so altogether, these findings highlight the significance of TMAO as a potential predictor of CKD risk and kidney function decline in community-based US adults. They also underscore the importance of monitoring TMAO levels as part of preventive strategies for CKD and suggest avenues for further research into the mechanistic links between TMAO and renal dysfunction.
Conclusion
The collaborative research effort between the Cleveland Clinic and Tufts University has unveiled a compelling link between elevated TMAO levels and the future risk of developing CKD. By identifying TMAO as a predictive biomarker, this study paves the way for earlier detection and targeted interventions to mitigate the burden of CKD on patients and healthcare systems worldwide.
And as the field of precision medicine continues to evolve, harnessing insights from metabolomics and gut microbiome research holds immense promise for revolutionizing our approach to kidney health and beyond.
References:
Meng W, Wilson T, Xinmin L, de Oliveira Otto M, Lee Y, Lemaitre R, et al. The gut microbial metabolite trimethylamine N-oxide,... : Journal of the American Society of Nephrology. JASN. April 9, 2024. Accessed April 23, 2024. https://journals.lww.com/jasn/abstract/9900/the_gut_microbial_metabolite_trimethylamine.282.aspx.
Research ties gut microbial TMAO pathway to chronic kidney disease. Medical Xpress . April 9, 2024. Accessed April 23, 2024. https://medicalxpress.com/news/2024-04-gut-microbial-tmao-pathway-chronic.html.
Zixin Y, Lulu C, Xiangchang Z, Qing F, Binjie Z, Chunyang L. Tmao as a potential biomarker and therapeutic target for chronic kidney disease: A Review. National Library of Medicine. August 12, 2022. Accessed April 23, 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9411716/.