학술논문
Overweight-obesity is associated with decreased vitamin K2 levels in hemodialysis patients
Document Type
research-article
Author
Ravera, Maura; Nickolas, Thomas; Plebani, Mario; Iervasi, Giorgio; Aghi, Andrea; Khairallah, Pascale; Gallieni, Maurizio; Mereu, Maria Cristina; Giannini, Sandro; Sella, Stefania; Zaninotto, Martina; Paoletti, Ernesto; Bussalino, Elisabetta; Di Lullo, Luca; Bellasi, Antonio; Cosmai, Laura; Foramitti, Marina; Malberti, Fabio; Brandi, Maria Luisa; Ferrari, Serge; Tripepi, Giovanni; Fusaro, Maria
Source
Clinical Chemistry and Laboratory Medicine (CCLM). 59(3):581-589
Subject
Language
English
ISSN
1437-4331
1434-6621
1434-6621
Abstract
ObjectivesObesity is an important risk factor for morbidity and mortality. Vitamin K2 is involved in the production of bone and matrix amino acid g-carboxy-glutamic acid (Gla) proteins (vitamin K-dependent proteins [VKDPs]), regulating bone and vascular calcification (VC). Bone Gla protein (BGP) is involved both in bone mineralization and VCs. We assessed the relationships between vitamin K levels and body mass index (BMI) according to the hypothesis that the impact of BMI on mortality is partly driven by low vitamin K levels.MethodsThe Vitamin K Italian (VIKI) study included 387 hemodialysis patients from 18 dialysis centers in Italy. We determined plasma levels of bone markers: vitamin K levels, VKDPs, vitamin 25(OH)D, alkaline phosphatase (ALP), parathyroid hormone (PTH), calcium (Ca), phosphorus (P) and routine biochemistry. BMI was classified into the following categories: underweight (BMI 2), normal weight (18.5 ≤ BMI 2), overweight (25 ≤ BMI 2) and obese (BMI ≥ 30 kg/m2).Results45.2% of patients were overweight or obese. Stratification by BMI demonstrated lower median menaquinone-7 (MK7)/triglycerides levels in obese patients (0.42 ng/mg [0.19, 0.87], p = 0.005). BGP levels were lower in overweight and obese patients (152 mcg/L [83.2, 251] and 104 mcg/L [62.7, 230], p = ConclusionsThese data are the first to report an inverse relationship between Vitamin K2 levels and BMI in hemodialysis patients. Further studies are needed to confirm these findings and to determine if lower levels of Vitamin K are related to greater morbidity and mortality in this at-risk population.