Apolipoprotein E polymorphism and vitamin K status in cystic fibrosis patients not supplemented with vitamin K

OBJECTIVE: ApoE alleles have been shown to significantly correlate with vitamin K status, however, data concerning this phenomenon in cystic fibrosis (CF) are scarce. This study aimed to investigate the effect of ApoE polymorphism on vitamin K status in a unique group of CF patients who had never received vitamin K supplementation. PATIENTS AND METHODS: The study group consisted of 93 CF patients aged from 3 months to 32 years. Vitamin K status was assessed by the concentration of prothrombin induced by vitamin K absence (PIVKA-II) and the percentage of undercarboxylated osteocalcin (u-OC). The clinical status was evaluated in all patients. RESULTS: Fifty-four (65.1%) out of 83 patients had a pathological PIVKA-II concentration (2 ng/ml) and an abnormal percentage of u-OC (>= 20%). There were no differences in the clinical parameters, including PIVKA-II concentration (p=0.7752) and u-OC percentage (p=0.8395), between patients with genotypes ApoE2/3, ApoE3/3 and ApoE3/4. Moreover, the frequency of vitamin K deficiency did not significantly differ in CF patients with ApoE2/3, ApoE3/3 and ApoE3/4 genotypes (66.7 vs. 69.9 vs. 80%, p=0.8411; 87.5 vs. 89.6 vs. 100%, p=1.000, respectively). CONCLUSIONS: The presence of the ApoE4 allele does not influence the vitamin K status in CF patients who have never received vitamin K supplementation.