In:
Clinical Chemistry and Laboratory Medicine (CCLM), Walter de Gruyter GmbH, Vol. 54, No. 7 ( 2016-7-1), p. 1201-1210
Abstract:
Background: Given the growing interest in the health benefits of vitamin K, there is great need for development of new high-throughput methods for quantitative determination of vitamin K in plasma. We describe a simple and rapid method for measurement of plasma vitamin K 1 (phylloquinone [PK]) and K 2 (menaquinones [MK]-4 and -7). Furthermore, we investigated the association of fasting plasma vitamin K with functional vitamin K insufficiency in renal transplant recipients (RTR). Methods: We used HPLC-tandem mass spectrometry with atmospheric pressure chemical ionization for measurement of plasma PK, MK-4, and MK-7. Solid-phase extraction was used for sample clean-up. Mass spectrometric detection was performed in multiple reaction monitoring mode. Functional vitamin K insufficiency was defined as plasma desphospho-uncarboxylated matrix Gla protein (dp-ucMGP) 〉 500 pmol/L. Results: Lower limits of quantitation were 0.14 nmol/L for PK and MK-4 and 4.40 nmol/L for MK-7. Linearity up to 15 nmol/L was excellent. Mean recoveries were 〉 92%. Fasting plasma PK concentration was associated with recent PK intake (ρ=0.41, p=0.002) and with plasma MK-4 (ρ=0.49, p 〈 0.001). Plasma PK (ρ=0.38, p=0.003) and MK-4 (ρ=0.46, p 〈 0.001) were strongly correlated with plasma triglyceride concentrations. Furthermore, we found that MK-4-triglyceride ratio, but not PK-triglyceride ratio, was significantly associated with functional vitamin K insufficiency (OR 0.22 [0.07–0.70], p=0.01) in RTR. Conclusions: The developed rapid and easy-to-use LC-MS/MS method for quantitative determination of PK, MK-4, and MK-7 in human plasma may be a good alternative for the labor-intensive and time-consuming LC-MS/MS methods and enables a higher sample throughput.
Type of Medium:
Online Resource
ISSN:
1437-4331
,
1434-6621
DOI:
10.1515/cclm-2015-0864
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2016
detail.hit.zdb_id:
1492732-9
SSG:
15,3
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