| Source: |
Witham, M, Lees, J S, White, M, Band, M, Bell, S, Chantler, D J, Ford, I, Fulton, R, Kennedy, G, Littleford, R, McCrea, I V, McGlynn, D, Panarelli, M, Ralston, M R, Rutherford, E, Severn, A, Thomson, N, Traynor, J P, Struthers, A D, Wetherall, K & Mark, P B 2020, 'Vitamin K supplementation to improve vascular stiffness in CKD : The K4Kidneys randomized controlled trial', Journal of the American Society of Nephrology, vol. 31, no. 10, pp. 2434-2445. https://doi.org/10.1681/ASN.2020020225 |
| Description: |
Background : Vascular calcification, a risk factor for cardiovascular disease, is common among patients with CKD and is an independent contributor to increased vascular stiffness and vascular risk in this patient group. Vitamin K is a cofactor for proteins involved in prevention of vascular calcification. Whether or not vitamin K supplementation could improve arterial stiffness in patients with CKD is unknown. Methods : To determine if vitamin K supplementation might improve arterial stiffness in patients in CKD, we conducted a parallel-group, double-blind, randomized trial in participants aged 18 or older with CKD stage 3b or 4 (eGFR 15-45 ml/min per 1.73 m 2 ). We randomly assigned participants to receive 400 mg oral vitamin K2 or matching placebo once daily for a year. The primary outcome was the adjusted between-group difference in carotid-femoral pulse wave velocity at 12 months. Secondary outcomes included augmentation index, abdominal aortic calcification, BP, physical function, and blood markers of mineral metabolism and vascular health. We also updated a recently published meta-analysis of trials to include the findings of this study. Results : We included 159 randomized participants in the modified intention-to-treat analysis, with 80 allocated to receive vitamin K and 79 to receive placebo. Mean age was 66 years, 62 (39%) were female, and 87 (55%) had CKD stage 4. We found no differences in pulse wave velocity at 12 months, augmentation index at 12 months, BP, B-type natriuretic peptide, or physical function. The updated meta-analysis showed no effect of vitamin K supplementation on vascular stiffness or vascular calcification measures. Conclusions : Vitamin K2 supplementation did not improve vascular stiffness or other measures of vascular health in this trial involving individuals with CKD. |