Abstract: SA-PO868

Vitamin K and Vascular Health: A Systematic Review and Meta-Analysis

Session Information

  • Vascular Calcification
    November 04, 2017 | Location: Hall H, Morial Convention Center
    Abstract Time: 10:00 AM - 10:00 AM

Category: Mineral Disease

  • 1205 Vascular Calcification

Authors

  • Lees, Jennifer S., University of Glasgow, Glasgow, United Kingdom
  • Chapman, Fiona A, NHS Greater Glasgow and Clyde, Glasgow, United Kingdom
  • Mark, Patrick B., University of Glasgow, Glasgow, United Kingdom
Background

Vitamin K deficiency is prevalent among patients with chronic kidney disease. Matrix Gla protein, an important regulator of vascular calcification, is dependent on adequate vitamin K intake. We conducted a systematic review and meta-analysis of effect of vitamin K supplementation on vascular health, and assessed evidence that level of desphospho-uncarboxylated Matrix Gla protein (dpucMGP) is associated with incident cardiovascular disease (CVD) or mortality.

Methods

Two authors searched Medline, Embase, Cochrane and Google for: i) adult human studies of vitamin K supplementation versus control which measured effect on vascular calcification, vascular stiffness or dpucMGP, and ii) prospective observational studies assessing effect of baseline dpucMGP on incident CVD or mortality. Random effects meta-analysis was conducted using meta and metafor packages for R statistical software package. Egger regression and Trim and Fill were used to assess for publication bias.

Results

Electronic searching identified i) 5095 and ii) 1850 references of which i) 8 and ii) 12 met our pre-specified inclusion criteria. In groups treated with vitamin K, there was a meaningful change in vascular calcification (see Figure, p=0.038) and dpucMGP (n=6, -235.5 (-292.1; -178.8) pmol/l, p<0.001), and a trend towards improvement in vascular stiffness (n=3, -3.70 (-7.77; 0.37) %, p=0.075). Over a median follow up period of 7.8 years (IQR 4.9-11.3), stepwise increase in dpucMGP was not associated with fatal or non-fatal CVD (log HR 0.06 (-0.1; 0.23), p=0.48) or mortality (log HR 0.02 (-0.11; 0.16), p=0.74). Egger regression and Trim and Fill analyes suggest a degree of publication bias in favour of positive results.

Conclusion

Vitamin K supplementation significantly reduces dpucMGP level, though dpucMGP is not associated with incident CVD or mortality. Supplementation appears to reduce progression of vascular calcification, with a trend towards improvement in vascular stiffness, though there are limited data available. Further clinical trials of the effect of vitamin K supplementation on vascular health are warranted.

Figure: Forest plot of random effcts meta-analysis: % change in calcification with vitamin K supplementation versus control