High Levels of Circulating Type II Collagen Degradation Marker (CTx-II) Are Associated with Specific VDR Polymorphisms in Patients with Adult Vertebral Osteochondrosis

Int J Mol Sci. 2017 Sep 29;18(10):2073. doi: 10.3390/ijms18102073.


Both vitamin D and collagen have roles in osteocartilaginous homeostasis. We evaluated the association between the circulating 25-hydroxyvitamin D (25(OH)D) type I and II collagen degradation products (CTx-I, and CTx-II), and four vitamin D receptor gene (VDR) polymorphisms, in Italian males affected by low back pain (LBP) due to herniation/discopathy and/or vertebral osteochondrosis. FokI, BsmI, ApaI, and TaqI VDR-polymorphisms were detected through PCR-restriction fragment length polymorphism (RFLP), and circulating 25(OH)D, CTx-I and CTx-II were measured by immunoassays in 79 patients (of which 26 had osteochondrosis) and 79 age-, sex- and body mass index (BMI)-matched healthy controls. Among all 158 subjects, carriers of FF and Ff genotypes showed lower 25(OH)D than ff, which suggested a higher depletion of vitamin D in F allele carriers. Higher CTx-I concentrations were observed in TT versus Tt among controls, and Tt versus tt among LBP cases, which suggested a higher bone-cartilaginous catabolism in subjects bearing the T allele. Higher CTx-II concentrations were observed in patients with osteochondrosis bearing FF, bb, TT, or Aa genotypes in comparison with hernia/discopathy patients and healthy controls. Vertebral osteochondrosis shows peculiar genotypic and biochemical features related to vitamin D and the osteocartilaginous metabolism. Vitamin D has roles in the pathophysiology of osteochondrosis.

Keywords: Italian males; VDR polymorphisms; adult vertebral osteochondrosis; type II collagen.

MeSH terms

  • Adult
  • Collagen Type II / blood*
  • Female
  • Gene Frequency
  • Genetic Predisposition to Disease
  • Genotype
  • Humans
  • Italy / epidemiology
  • Male
  • Middle Aged
  • Peptide Fragments / blood*
  • Polymorphism, Genetic*
  • Proteolysis
  • Receptors, Calcitriol / genetics*
  • Spinal Osteochondrosis / blood*
  • Spinal Osteochondrosis / epidemiology
  • Spinal Osteochondrosis / genetics*
  • Young Adult


  • C-terminal cross-linking telopeptide of type II collagen, human
  • Collagen Type II
  • Peptide Fragments
  • Receptors, Calcitriol
  • VDR protein, human