OBJECTIVES: We aimed to measure the vasodilating effects of vitamin C on the radial arteries of healthy subjects and to assess whether vitamin C is superior in this regard to diltiazem, a commonly used vasodilator in coronary artery bypass using radial conduits. METHODS: In a case-control study (study 1) oral single-dose vitamin C (2 g) was given to 15 healthy nonsmokers and 15 matched otherwise healthy smokers. In a randomized double-blind study (study 2) oral single-dose vitamin C (2 g, n = 15) and diltiazem (180 mg, n = 15) were compared in preoperative patients with coronary artery disease. We examined the dilation of the radial artery with high-resolution ultrasonography and measurement of the lumen surface and color Doppler images of the nondominant radial artery just before and 2 hours after drug administration. RESULTS: In study 1 both smokers and nonsmokers showed a significant increase in the lumen surface at 2 hours compared with at baseline (P <.001 and P =.013, respectively). The increase was larger in smokers (median, 37.5% vs 14.3%; P =.004). In study 2 both groups showed statistically significant increases in the lumen surface at 2 hours compared with at baseline (P <.001 and P =.008 for vitamin C and diltiazem, respectively). Vitamin C achieved a larger increase than diltiazem (median, 33.3% vs 18.2%; P =.016). In multivariate modeling the increase in lumen surface was independently predicted by use of vitamin C over diltiazem (+21.2%, P =.007), diabetes mellitus (+14.5%, P =.085), increased cholesterol (+26.2%, P =.001), and smoking history (+20.8%, P =.017). CONCLUSIONS:Vitamin C is a potent acute vasodilator in both smokers and nonsmokers and is superior to diltiazem in preoperative coronary patients who need protection from vasospasm of the radial conduit.
RCT Entities:
OBJECTIVES: We aimed to measure the vasodilating effects of vitamin C on the radial arteries of healthy subjects and to assess whether vitamin C is superior in this regard to diltiazem, a commonly used vasodilator in coronary artery bypass using radial conduits. METHODS: In a case-control study (study 1) oral single-dose vitamin C (2 g) was given to 15 healthy nonsmokers and 15 matched otherwise healthy smokers. In a randomized double-blind study (study 2) oral single-dose vitamin C (2 g, n = 15) and diltiazem (180 mg, n = 15) were compared in preoperative patients with coronary artery disease. We examined the dilation of the radial artery with high-resolution ultrasonography and measurement of the lumen surface and color Doppler images of the nondominant radial artery just before and 2 hours after drug administration. RESULTS: In study 1 both smokers and nonsmokers showed a significant increase in the lumen surface at 2 hours compared with at baseline (P <.001 and P =.013, respectively). The increase was larger in smokers (median, 37.5% vs 14.3%; P =.004). In study 2 both groups showed statistically significant increases in the lumen surface at 2 hours compared with at baseline (P <.001 and P =.008 for vitamin C and diltiazem, respectively). Vitamin C achieved a larger increase than diltiazem (median, 33.3% vs 18.2%; P =.016). In multivariate modeling the increase in lumen surface was independently predicted by use of vitamin C over diltiazem (+21.2%, P =.007), diabetes mellitus (+14.5%, P =.085), increased cholesterol (+26.2%, P =.001), and smoking history (+20.8%, P =.017). CONCLUSIONS:Vitamin C is a potent acute vasodilator in both smokers and nonsmokers and is superior to diltiazem in preoperative coronary patients who need protection from vasospasm of the radial conduit.
Authors: Houli Jiang; Fiona E Harrison; Kavita Jain; Samantha Benjamin; James M May; Joan P Graves; Darryl C Zeldin; John R Falck; Bruce D Hammock; John C McGiff Journal: Adv Biosci Biotechnol Date: 2012-06-01
Authors: Chang Ye Wang; Jacob Dudzinski; Derek Nguyen; Eric Armbrecht; Ian A Maher Journal: JAMA Facial Plast Surg Date: 2019-09-01 Impact factor: 4.611