The following is the summary of “Higher serum trimethylamine-N-oxide levels are associated with increased abdominal aortic calcification in hemodialysis patients” published in the November 2022 issue of Renal failure by He, et al.

Dialysis patients have an increased risk of developing cardiovascular disease and dying from it due to the prevalence of vascular calcification (VC). However, it is not quite obvious how the mechanisms work. Another molecule derived from the gut microbiota that has been linked to adverse cardiovascular outcomes in hemodialysis (HD) patients is trimethylamine-N-oxide (TMAO). The purpose of this research is to compare VC in HD patients with different serum TMAO levels. Researchers used high-performance liquid chromatography-mass spectrometry to analyze TMAO levels in the serum. 

The degree of vascular calcification was determined by measuring abdominal aortic calcification (AAC). Participants were separated into high and low AAC score groups using a threshold value of 5.5. This cross-sectional study included 184 HD patients and 39 healthy controls. HD patients had greater serum Ln(TMAO) values (1.82 ± 0.62 vs. -1.60 ± 0.77, P<0.001) than control subjects. In addition, HD patients with high AAC scores had higher blood Ln(TMAO) levels than those with low AAC scores (2.09 ± 0.55 vs. 1.67±   0.54, P<0.001). 

Serum low-molecular-weight thiol—nitropropionic acid (LnTMAO), HD year, diabetes mellitus, age, and plasma intact parathyroid hormone (iPTH) were all found to be significant predictors of VC in HD patients in the multivariate regression analysis. In HD patients, increased risk for VC was shown to be associated with higher blood TMAO levels, greater age, longer HD vintage, higher plasma iPTH, and the presence of diabetic mellitus. This study suggests a potential therapeutic target for the treatment of VC and warrants additional research into the underlying mechanism.

Source: tandfonline.com/doi/full/10.1080/0886022X.2022.2145971