Vitamin D3-Induced Arterial Calcification Decreases Functional Recovery And Limb Perfusion In A Murine Model Of Hindlimb Ischemia

Objectives: Clinical studies demonstrate associations between arterial calcification and adverse outcomes in patients with peripheral arterial disease. The causal relationship between calcification and ischemia, however, remains unclear. This study aims to evaluate the effects of arterial calcification on functional recovery and limb perfusion following acute limb ischemia in a murine model. Methods: Arterial calcification was induced in 64 Sprague-Dawley rats using Vitamin D 3 . A control group of 32 rats received vehicle only. After 2 weeks, to allow for calcification, unilateral hindlimb ischemia was induced by ligation and excision of the superficial femoral artery. At weekly intervals, functional and ischemia status were evaluated in a blinded manner and laser Doppler perfusion imaging was performed. Results: Calcium assay demonstrated greater arterial calcification in the superficial femoral arteries (0.1 vs. 17.0, P < .01) of Vitamin D 3 injected animals. Rats injected with Vitamin D3 showed significantly worse Tarlov, Ischemia, Modified Ischemia, and Total Ischemia scores at each post-operative time point (Week 1: 16.6 vs. 14.5 P <.01, Week 2: 17.1 vs. 14.5 P <.01, Week 3 17.5 vs. 15.0 P < .01). The control group regained normal functional status by week 4; however Vitamin D3-injected rats did not return to baseline by the conclusion of the study (17.9 vs. 16.6, P < .01). Laser Doppler perfusion revealed decreased raw perfusion values pre-operatively (616 vs. 428, P < .01) and at weekly intervals beginning at week 2 in both the ischemic and non-ischemic limbs among animals with calcified arteries as compared to controls (Table 1). Conclusions: Vitamin D3 induced calcification is associated with decreased perfusion and worse functional recovery in a rat model of hindlimb ischemia. Future research aimed at understanding the relationship between vitamin D 3 , arterial calcification, and lower extremity ischemia may help to improve outcomes in patients with PAD.