Furong Zhao

Purpose: To determine the reference intervals of homocysteine (Hcy) metabolic pathway in healthy adults using direct continuous sampling, and to explore their correlations with coronary atherosclerosis (CA) for improving the risk assessment and diagnostic accuracy of CA. Patients and Methods: A total of 426 reference individuals were selected via direct continuous sampling of the two centers from healthy adults based on questionnaires and laboratory indicators. Additionally, 75 patients were diagnosed with CA by cardiologists. Standardized analysis of Hcy, cysteine (Cys) and methionine (Met) levels in serum were conducted using commercial assay kits compatible with LC-MS/MS. Results: Although Met and Hcy showed significant differences between the sexes, they could not meet the criteria for setting reference intervals. After outlier removal and normality conversion, 95% reference intervals of Hcy, Cys and Met were calculated as 7– 25 μmol/L, 227– 410 μmol/L, and 21– 39 μmol/L, respectively. In addition, the correlations among Hcy, Cys, and Met were influenced by CA, and each served as an independent risk factor. The area under the curve (AUC) for the combined three indicators increased to 0.86 (95% CI: 0.81– 0.91). The specificity increased to 83%, while the sensitivity reached 78%. Conclusion: The Hcy metabolic pathway significantly enhances risk assessment capability and may be helpful in providing reference values for the diagnosis and risk prediction of CA.

Omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFAs) are indispensable for human health. Notably, imbalanced levels of maternal PUFAs during pregnancy can exert lasting impacts on the developing fetus. There is an urgent need for a robust and rapid method that can simultaneously quantify multiple n-3 and n-6 PUFAs in plasma and adapt to large-scale clinical screening. Sample preparative process consisted of non-derivatized alkali hydrolyzing and liquid-liquid extraction followed by reconstituting after being blown dry with nitrogen, and the total chromatographic run time was only 5.6 min. The LC-MS/MS method was validated according to current national and international guidelines. Acceptable reproducibility and accuracy were shown based on the intra-day precision was 1.79%-7.02%, the inter-day precision was 0.01%-5.63%, and the accuracy was 87.42%-102.78%. The correlation coefficients of linearity were >0.9930. All measured plasma individual PUFAs levels in pregnant women significantly increased, apart from eicosapentaenoic acid (EPA, C20:5n3) and n-6/n-3 PUFA ratio levels decreased were observed. The analysis performance is satisfactory and suitable for clinical routine detection. This method could be a valuable tool for 10 kinds of n-3 and n-6 PUFAs nutritional assessment, supplementary guidance, and intervention during pregnancy.