Iron reduction response and demographic differences between diabetics and non-diabetics with cardiovascular disease entered into a controlled clinical trial.

Iron-catalyzed oxygen-free radical-induced oxidative stress mediates the pathogenesis of diabetes and cardiovascular disease (CVD). Diabetics (n = 473) and non-diabetics (n = 804) with CVD entered into a randomized trial of iron (ferritin) reduction by calibrated phlebotomy (, Identifier NCT00032357) had comparable iron measures at entry but diabetics had a greater burden of CVD and comorbidities, lower hemoglobin and hematocrit levels, and higher glucose levels than non-diabetics. Entry iron measures were lower in diabetics on hypoglycemic therapy compared to previously untreated diabetics. Diabetics and non-diabetics had comparable iron measures during follow-up. The Loess analysis of paired ferritin and hemoglobin, and paired ferritin and glucose levels in diabetics randomized to phlebotomy showed higher ferritin levels associated with lower hemoglobin and higher glucose levels. Progressive ferritin reduction in diabetics correlated with increasing hemoglobin and decreasing glucose levels, neither of which reached levels observed in non-diabetics. We postulate that phlebotomy-triggered autophagy (ferritinophagy) released redox-active iron sequestered intracellularly, worsening anemia and glucose utilization that corrected partially with ferritin reduction. Intracellular redox-active iron levels contributory to disease, not reflected in peripheral iron measures, may persist because of glycation of iron transport proteins in diabetes. These findings suggest novel strategies for disease prevention and improving outcomes in diabetes and CVD.

Ferritin and Percent Transferrin Saturation Levels Predict Type 2 Diabetes Risk and Cardiovascular Disease Outcomes.

INTRODUCTION: Type 2 diabetes (T2D) and cardiovascular disease (CVD) risk associate with ferritin and percent transferrin saturation (%TS) levels. However, increased risk has been observed at levels considered within the "normal range" for these markers. OBJECTIVE: To define normative ferritin and %TS levels associated with T2D and CVD risk. METHODS: Six-monthly ferritin, %TS and hemoglobin levels from 1,277 iron reduction clinical trial participants with CVD (peripheral arterial disease, 37% diabetic) permitted pair-wise analysis using Loess Locally Weighted Smoothing plots. Curves showed continuous quantitative ferritin, hemoglobin (reflecting physiologic iron requirements), and %TS (reflecting iron transport and sequestration) levels over a wide range of values. Inflection points in the curves were compared to ferritin and %TS levels indicating increased T2D and CVD risk in epidemiologic and intervention studies. RESULTS: Increasing ferritin up to about 80 ng/mL and %TS up to about 25% TS corresponded to increasing hemoglobin levels, and minimal T2D and CVD risk. Displaced Loess trajectories reflected lower hemoglobin levels in diabetics compared to non-diabetics. Ferritin levels up to about 100 ng/mL paralleled proportionately increasing %TS levels up to about 55%TS corresponding to further limitation of T2D and CVD risk. Ferritin levels over 100 ng/mL did not associate with hemoglobin levels and coincided with increased T2D and CVD risk. CONCLUSIONS: Recognition of modified normal ranges for ferritin from about 15 ng/mL up to about 80- 100 ng/mL and %TS from about 15% up to about 25-55% may improve the value of iron biomarkers to assess and possibly lower T2D and CVD risk.

Anticoagulation, ferrotoxicity and the future of translational lung cancer research.

Numerous studies have shown that elements of coagulation reactions mediate tumor cell proliferation, motility (invasiveness), tissue remodeling and metastasis. Coagulation activation is virtually a universal feature of human malignancy that differs from the clotting response to injury in that it is self-perpetuating rather than self-attenuating. Coagulation activation participates in tumor matrix deposition and local inflammation, and predicts subsequent cancer risk and adverse cancer outcomes. Several clinical trials of anticoagulants have shown improved outcomes in small cell carcinoma of the lung (SCCL) that have been correlated with assembly on the tumor cells of an intact coagulation pathway. However, variable efficacy of anticoagulant therapy has raised doubts about the coagulation hypothesis. Recently, initiators of coagulation and fibrinolytic pathways have been identified that mediate tumor inception and progression. Notable among these is oxidative stress driven by iron-catalyzed reactive oxygen species that may be the basis for local coagulation activation, tumor matrix deposition, inflammation and aberrant properties characteristic of the malignant phenotype. Recognition of important biological characteristics of individual tumor types, disease stage, choice of standard therapy including chemotherapy and the iron status of the host may clarify mechanisms. All of these are subject to modification based on controlled clinical trial design. Further tests of the coagulation hypothesis may lead to novel, low cost and relatively non-toxic approaches to treatment of malignancy including lung cancer that contrast with certain current cancer treatment paradigms.

Racial Health Disparities, and Variant Red Cell and Iron Homeostasis.

Oxidative stress from excess iron may contribute to racial health disparities. Previously we reported improved clinical outcomes with lower ferritin and higher percent transferrin saturation (%TS) levels in White but not Black participants with peripheral arterial disease entered to a clinical trial. This report demonstrates racially variant interactions between hemoglobin, ferritin, and %TS levels. Lower hemoglobin and %TS levels, and higher ferritin levels were documented in Black compared with White participants within cardiovascular disease risk categories. Ferritin levels near 80 ng/mL related to higher hemoglobin levels in White but not Black participants. Higher %TS levels with ferritin levels above 80 ng/mL in White participants were blunted in Black participants. Ferritin/%TS ratios were significantly higher in Black than White participants. Iron incorporation into hemoglobin and scavenging by transferrin may buffer iron toxicity more effectively in White than in Black individuals. Metabolic vulnerability to iron excess may explain, in part, racial health disparities.

Racial differences in iron measures and outcomes observed during an iron reduction trial in peripheral arterial disease.

Elevated body iron (ferritin) levels may contribute to adverse health outcomes. Racial differences in iron measures and clinical outcomes were observed during an iron reduction trial in peripheral arterial disease. At entry, Black compared with White participants had higher ferritin and lower red cell measures, as well as differing ferritin and percent transferrin saturation (%TS) responses, and HDL/LDL ratios associated with statin use. Lower hematocrit levels during follow-up resulted in fewer phlebotomies, less iron unloading (ferritin reduction, p=.035) and 32% less iron removed in Black compared with White participants randomized to iron reduction. Improved primary (all-cause mortality) and secondary (death plus non-fatal myocardial infarction and stroke) outcomes among White participants correlated with lower ferritin levels (p=.005 and p=.053, respectively) and higher %TS levels (p<.001 and p=.001 respectively), associations not observed in Black participants. Variant iron homeostasis contributory to racial health disparities warrants personalized intervention strategies and race-specific clinical trial design.

Reduction of iron stores and clinical outcomes in peripheral arterial disease: outcome comparisons in smokers and non-smokers.

A prospective randomized trial suggested that iron (ferritin) reduction improved outcomes in smokers. The present study reanalyzed the trial results in smokers compared with non-smokers. Randomization of 1262 men with peripheral arterial disease (540 smokers and 722 non-smokers) to iron reduction (phlebotomy) or control groups permitted analysis of the effects of iron reduction and smoking on primary (all-cause mortality) and secondary (death plus non-fatal myocardial infarction or stroke) endpoints. Iron reduction resulted in significant improvement in the primary (hazard ratio [HR] 0.661, 95% confidence interval [CI] 0.45, 0.97; P = 0.036) and secondary (HR 0.64, 95% CI 0.46, 0.88; P = 0.006) endpoints compared with controls in smokers but not in non-smokers. Smokers required removal of a greater volume of blood to attain targeted ferritin reduction as compared with non-smokers (P = 0.003) and also exhibited differing characteristics from non-smokers, including significantly less statin use. Phlebotomy-related outcomes favored smokers over non-smokers. Biological linkages responsible for this unique effect offer promising lines for future iron reduction studies (ClinicalTrial.Gov Identifier: NCT00032357).

The statin-iron nexus: anti-inflammatory intervention for arterial disease prevention.

OBJECTIVES: We postulated the existence of a statin-iron nexus by which statins improve cardiovascular disease outcomes at least partially by countering proinflammatory effects of excess iron stores. METHODS: Using data from a clinical trial of iron (ferritin) reduction in advanced peripheral arterial disease, the Iron and Atherosclerosis Study, we compared effects of ferritin levels versus high-density lipoprotein to low-density lipoprotein ratios (both were randomization variables) on clinical outcomes in participants receiving and not receiving statins. RESULTS: Statins increased high-density lipoprotein to low-density lipoprotein ratios and reduced ferritin levels by noninteracting mechanisms. Improved clinical outcomes were associated with lower ferritin levels but not with improved lipid status. CONCLUSIONS: There are commonalities between the clinical benefits of statins and the maintenance of physiologic iron levels. Iron reduction may be a safe and low-cost alternative to statins.

Effect of controlled reduction of body iron stores on clinical outcomes in peripheral arterial disease.

BACKGROUND: Published results from a controlled clinical trial in patients with peripheral arterial disease found improved outcomes with iron (ferritin) reduction among middle-aged subjects but not the entire cohort. The mechanism of the age-specific effect was explored. METHODS: Randomization to iron reduction (phlebotomy, n = 636) or control (n = 641) stratified by prognostic variables permitted analysis of effects of age and ferritin on primary (all-cause mortality) and secondary (death, nonfatal myocardial infarction, and stroke) outcomes. RESULTS: Iron reduction improved outcomes in youngest age quartile patients (primary outcome hazard ratio [HR] 0.44, 95% CI 0.21-0.92, P = .028; secondary outcome HR 0.34, 95% CI 0.19-0.61, P < .001). Mean follow-up ferritin levels (MFFL) declined with increasing entry age in controls. Older age (P = .035) and higher ferritin (P < .001) at entry predicted poorer compliance with phlebotomy and rising MFFL in iron-reduction patients. Intervention produced greater ferritin reduction in younger patients. Improved outcomes with lower MFFL were found in iron-reduction patients (primary outcome HR 1.11, 95% CI 1.01-1.23, P = .028; secondary outcome HR 1.10, 95% CI 1.0-1.20, P = .044) and the entire cohort (primary outcome HR 1.11, 95% CI 1.01-1.23, P = .037). Improved outcomes occurred with MFFL below versus above the median of the entire cohort means (primary outcome HR 1.48, 95% CI 1.14-1.92, P = .003; secondary outcome HR 1.22, 95% CI 0.99-1.50, P = .067). CONCLUSIONS: Lower iron burden predicted improved outcomes overall and was enhanced by phlebotomy. Controlling iron burden may improve survival and prevent or delay nonfatal myocardial infarction and stroke.

Prohemostatic therapy: the rise and fall of aprotinin.

Aprotinin has been used clinically to enhance hemostasis for decades and was approved in the United States by the Food and Drug Administration in 1993 to reduce the transfusion requirement during coronary artery bypass surgery. Marketing of aprotinin ceased recently when observational studies and a randomized clinical trial reported increased cardiovascular toxicity in patients receiving this drug. The importance of prohemostatic therapy is reviewed in light of new information on long-term deleterious effects of blood transfusion, including increased risk of cardiovascular disease, malignancy, and infection possibly attributable to delivery of a load of red cell-derived redox-active iron. Weaknesses in design of clinical trials that failed to control adequately for such alternative mechanisms of toxicity complicate interpretation of risks versus benefits in clinical trials of aprotinin given to reduce transfusion requirement in the acute surgical setting. Properties and applications of aprotinin that may not have received sufficient attention in the decision to remove this drug from the therapeutic armamentarium are reviewed. Potential application of prohemostatic drugs, including aprotinin to special populations at risk for operative blood loss requiring transfusion, is illustrated by the description of nine patients with coagulopathies whose operative bleeding was managed effectively with aprotinin. This drug may remain safe and effective in patients at risk of bleeding with surgery. Beneficial effects of aprotinin seemingly unrelated to its prohemostatic properties, especially its apparent striking antineoplastic effects, warrant further study.

Ferritin levels, inflammatory biomarkers, and mortality in peripheral arterial disease: a substudy of the Iron (Fe) and Atherosclerosis Study (FeAST) Trial.

BACKGROUND: This study delineated correlations between ferritin, inflammatory biomarkers, and mortality in a cohort of 100 cancer-free patients with peripheral arterial disease (PAD) participating in the Veterans Affairs (VA) Cooperative Study #410, the Iron (Fe) and Atherosclerosis Study (FeAST). FeAST, a prospective, randomized, single-blind clinical trial, tested the hypothesis that reduction of iron stores using phlebotomy would influence clinical outcomes in 1227 PAD patients randomized to iron reduction or control groups. The effects of statin administration were also examined in the Sierra Nevada Health Care (SNHC) cohort by measuring serum ferritin levels at entry and during the 6-year study period. No difference was documented between treatment groups in all-cause mortality and secondary outcomes of death plus nonfatal myocardial infarction and stroke. Iron reduction in the main study caused a significant age-related improvement in cardiovascular disease outcomes, new cancer diagnoses, and cancer-specific death. METHODS: Tumor necrosis factor (TNF)-alpha, TNF-alpha receptors 1 and 2, interleukin (IL)-2, IL-6, IL-10, and high-sensitivity C reactive protein (hs-CRP) were measured at entry and at 6-month intervals for 6 years. Average levels of ferritin and lipids at entry and at the end of the study were compared. The clinical course and ferritin levels of 23 participants who died during the study were reviewed. RESULTS: At entry, mean age of entry was 67 +/- 9 years for the SNHCS cohort, comparable to FeAST and clinical and laboratory parameters were equivalent in substudy participants randomized to iron reduction (n = 51) or control (n = 49). At baseline, 53 participants on statins had slightly lower mean entry-level ferritin values (114.06 ng/mL; 95% confidence interval [CI] 93.43-134.69) vs the 47 off statins (127.62 ng/mL; 95% CI, 103.21-152.02). Longitudinal analysis of follow-up data, after adjusting for the phlebotomy treatment effect, showed that statin use was associated with significantly lower ferritin levels (-29.78 ng/mL; Cohen effect size, -0.47 [t(df, 134) = 2.33, P = .02]). Mean follow-up average ferritin levels were higher in 23 participants who died (132.5 ng/mL; 95% CI, 79.36-185.66) vs 77 survivors (83.6 ng/mL; 95% CI, 70.34-96.90; Wilcoxon P = .05). Mean follow-up IL-6 levels were higher in dead participants (21.68 ng/mL; 95% CI, 13.71-29.66) vs survivors (12.61 ng/mL; 95% CI, 10.72-14.50; Wilcoxon P = .018). Ferritin levels correlated (Pearson) with average IL-6 levels (r = 0.1845; P = .002) and hsCRP levels (r = .1175; P = .04) during the study. CONCLUSION: These data demonstrate statistical correlations between levels of ferritin, inflammatory biomarkers, and mortality in this subset of patients with PAD.