Decreased cancer risk after iron reduction in patients with peripheral arterial disease: results from a randomized trial.

BACKGROUND: Excess iron has been implicated in cancer risk through increased iron-catalyzed free radical-mediated oxidative stress. METHODS: A multicenter randomized, controlled, single-blinded clinical trial (VA Cooperative Study #410) tested the hypothesis that reducing iron stores by phlebotomy would influence vascular outcomes in patients with peripheral arterial disease. Patients without a visceral malignancy in the last 5 years (n = 1277) were randomly assigned to control (n = 641) or iron reduction (n = 636). Occurrence of new visceral malignancy and cause-specific mortality data were collected prospectively. Cancer and mortality outcomes in the two arms were compared using intent-to-treat analysis with a Cox proportional hazards regression model. Statistical tests were two-sided. RESULTS: Patients were followed up for an average of 4.5 years. Ferritin levels were similar in both groups at baseline but were lower in iron reduction patients than control patients across all 6-month visits (mean = 79.7 ng/mL, 95% confidence interval [CI] = 73.8 to 85.5 ng/mL vs 122.5 ng/mL, 95% CI = 115.5 to 129.5 ng/mL; P < .001). Risk of new visceral malignancy was lower in the iron reduction group than in the control group (38 vs 60, hazard ratio [HR] = 0.65, 95% CI = 0.43 to 0.97; P = .036), and, among patients with new cancers, those in the iron reduction group had lower cancer-specific and all-cause mortality (HR = 0.39, 95% CI = 0.21 to 0.72; P = .003; and HR = 0.49, 95% CI = 0.29 to 0.83; P = .009, respectively) than those in the control group. Mean ferritin levels across all 6-monthly visits were similar in patients in the iron reduction and control groups who developed cancer but were lower among all patients who did not develop cancer than among those who did (76.4 ng/mL, 95% CI = 71.4 to 81.4 ng/mL, vs 127.1 ng/mL, 95% CI = 71.2 to 183.0 ng/mL; P = .017). CONCLUSIONS: Iron reduction was associated with lower cancer risk and mortality. Further studies are needed to define the role of body iron in cancer risk.

Reduction of iron stores and cardiovascular outcomes in patients with peripheral arterial disease: a randomized controlled trial.

CONTEXT: Accumulation of iron in excess of physiologic requirements has been implicated in risk of cardiovascular disease because of increased iron-catalyzed free radical-mediated oxidative stress. OBJECTIVE: To test the hypothesis that reducing body iron stores through phlebotomy will influence clinical outcomes in a cohort of patients with symptomatic peripheral arterial disease (PAD). DESIGN, SETTING, AND PATIENTS: Multicenter, randomized, controlled, single-blinded clinical trial based on the Iron (Fe) and Atherosclerosis Study (FeAST) (VA Cooperative Study #410) and conducted between May 1, 1999, and April 30, 2005, within the Department of Veterans Affairs Cooperative Studies Program and enrolling 1277 patients with symptomatic but stable PAD. Those with conditions likely to cause acute-phase increase of the ferritin level or with a diagnosis of visceral malignancy within the preceding 5 years were excluded. Analysis was by intent-to-treat. INTERVENTION: Patients were assigned to a control group (n = 641) or to a group undergoing reduction of iron stores by phlebotomy with removal of defined volumes of blood at 6-month intervals (avoiding iron deficiency) (n = 636), stratified by hospital, age, and baseline smoking status, diagnosis of diabetes mellitus, ratio of high-density to low-density lipoprotein cholesterol level, and ferritin level. MAIN OUTCOME MEASURES: The primary end point was all-cause mortality; the secondary end point was death plus nonfatal myocardial infarction and stroke. RESULTS: There were no significant differences between treatment groups for the primary or secondary study end points. All-cause deaths occurred in 148 patients (23%) in the control group and in 125 (20%) in the iron-reduction group (hazard ratio (HR), 0.85; 95% confidence interval (CI), 0.67-1.08; P = .17). Death plus nonfatal myocardial infarction and stroke occurred in 205 patients (32%) in the control group and in 180 (28%) in the iron-reduction group (HR, 0.88; 95% CI, 0.72-1.07; P = .20). CONCLUSION: Reduction of body iron stores in patients with symptomatic PAD did not significantly decrease all-cause mortality or death plus nonfatal myocardial infarction and stroke. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT00032357.

Implementation of an iron reduction protocol in patients with peripheral vascular disease: VA cooperative study no. 410: the Iron (Fe) and Atherosclerosis Study (FeAST).

BACKGROUND: Iron accumulates imperceptibly over time in adults because intake exceeds loss and because no physiologic mechanism exists for excreting levels that may be toxic. Levels of stored iron represented by the serum ferritin concentration have been implicated in the pathogenesis of vascular (and other) diseases, but the role of such stored iron remains controversial. Our hypothesis was that reduction in body iron stores to levels typical of children and premenopausal women (corresponding to ferritin levels of approximately 25 ng/mL) would alter morbidity and mortality rates in patients with advanced peripheral vascular disease. METHODS AND RESULTS: A randomized, single-blinded, clinical trial of graded reduction of iron stores by controlled phlebotomy was undertaken in patients with advanced peripheral vascular disease. Details of implementation of the protocol for testing this unusual experimental intervention are reported. CONCLUSIONS: A methodology is described for testing the concept that reduction of body iron stores (while avoiding iron deficiency) may alter disease outcomes. This methodology appears to be suitable for further testing to determine whether levels of iron stores presumed to be pathologic contribute to disease initiation or progression.