Effects of 12 Weeks of Oral Iron Supplementation on Skeletal Muscle Iron Content, Mitochondrial Function, and Indices of Aerobic Fitness in Healthy Females With Suboptimal Iron Stores
试验速览
- 阶段
- 1 期
- 状态
- 尚未招募
- 入组人数
- 36
- 试验地点
- 2
- 主要终点
- Muscle Ferritin
研究概览
简要总结
The goal of this clinical trial is to learn whether oral iron supplementation will increase skeletal muscle iron storage and its effects on exercise capacity in females with suboptimal iron status. The study will include healthy females, ages 18-40, who either have suboptimal or optimal iron stores.
The main questions it aims to answer are:
- Does iron supplementation increase skeletal muscle iron storage and alter the expression of iron-related and mitochondrial proteins?
- Does iron supplementation improve single-leg exercise performance?
- Is serum ferritin correlated with the abundance of iron-related proteins in skeletal muscle?
Researchers will compare outcomes from females with suboptimal iron status who receive oral iron supplementation to those who receive a placebo to see if supplementation improves muscle iron storage, protein expression, and exercise performance. Additionally, a non-intervention control group with optimal iron status will be included to assess baseline differences.
Participants will:
- Be randomly assigned to receive 150 mg elemental iron or placebo (maltodextrin) every other day for 12 weeks
Complete pre- and post-supplementation testing, including:
- Blood draws to assess iron status
- Skeletal muscle biopsies to analyze protein content
- Whole-body and single-leg exercise tests to assess performance
- Controls will undergo baseline-only testing to compare physiological and biochemical markers
详细描述
This study is intended to evaluate the effects of oral iron supplementation on muscle iron levels in females with suboptimal iron status. The design involves both a randomized controlled trial (RCT) for those with low blood iron levels, as well as a cross-sectional component, including only healthy controls. Iron supplementation will be administered to half of those enrolled in the RCT portion to evaluate the effects of iron uptake within the muscle. Therefore, the primary goal of the study is to determine if iron is stored within the muscle in meaningful amounts following an extended period of oral iron supplementation in healthy females with suboptimal iron status.
The study's rationale extends from the high prevalence of low iron levels among females globally, especially among those who are involved in endurance sports. At the level of the muscle, iron serves in several key biological functions, including oxygen transport, energy production, and even recovery from exercise, making it essential for performance. Although the investigators understand some amount of iron is stored within the muscle, the investigators are currently unaware whether meaningful changes occur following a period of supplementation. Therefore, the proposed protocol outlined below is designed to test the hypothesis that taking iron for a prolonged period at adequate doses will result in meaningful changes.
Participants involved in this study will include biological females aged 18-40 with suboptimal iron status (blood ferritin ≤50 µg/L), who are otherwise healthy, for the RCT portion, or normal iron status (blood ferritin ≥50 µg/L) for healthy controls. Interested participants will be screened, and those eligible for the RCT will be randomly assigned to either an oral iron supplement or a placebo sugar pill, ensuring that the encapsulation is preserved to promote blinding. Participants will consume the assigned treatment once every 2nd day for 12 weeks. Exercise and other biological tests will be performed both before and after supplementation during the RCT, while healthy controls will only participate in baseline testing.
The following is an overview of the study design:
Baseline testing
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 40 Years（Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •biologically female
- •between the ages of 18-40 years of age at the time of enrolment
- •plasma ferritin ≤ 50 µg/ L (RCT) or >50 µg/L (controls)
- •complete Get Active Questionnaire (GAQ: Canadian Society for Exercise Physiology) without contraindication
排除标准
- •have a body mass index (BMI) > 30 kg/m2
- •taking medications that have been shown to affect cardiovascular, respiratory, or metabolic responses to exercise (e.g., β-blockers, anti-inflammatories, anti-coagulants, insulin, etc.)
- •hemoglobin ≤ 120 g/L (anemia cut-off for women)
- •have known health problems or contraindications that prohibit exercise, including renal or gastrointestinal disorders, metabolic disease, heart disease, vascular disease, arthritis, diabetes, respiratory disease, uncontrolled blood pressure, dizziness, thyroid problems, or any other health conditions that are being treated and deemed likely to confound the results
- •dieting for weight loss or following a low-carbohydrate diet (known to affect iron homeostasis)
- •history of smoking or using tobacco products
- •consuming excessive amounts of alcohol (>21 units/week)
- •supplementing with iron (>5mg/day) in the last 3 months
- •any blood donation or surgeries in the past 3 months
- •antibiotic use within the previous four weeks before study enrolment
- •current laxative use
- •known history of thalassemia
- •known bleeding disorder
- •chronic use of nonsteroidal anti-inflammatory drugs
- •Currently/last 3 months taking prescription medications that are known to affect iron absorption (i.e. Antacids/PPIs (e.g., omeprazole), H2 Blockers (e.g., ranitidine), Tetracycline Antibiotics (e.g., doxycycline), Quinolone Antibiotics (e.g., ciprofloxacin), Cholestyramine, Colchicine, Methyldopa).
- •currently pregnant or plans to get pregnant within the duration of the study, and
- •do not understand English
- •Participants will be removed from the study if they begin taking any other forms of supplemental iron or choose to donate blood
研究组 & 干预措施
Iron supplement
Dietary supplement: Oral iron supplement, encapsulated ferrous sulphate (150mg elemental iron)
干预措施: Oral iron supplement (Dietary Supplement)
Placebo
Placebo control: Sugar pill, encapsulated polysaccharide substance (malodextrin)
干预措施: Placebo (Other)
结局指标
主要结局
Muscle Ferritin
时间窗: At baseline (week 0) and completion of supplementation (week 12)
Muscle collection: The muscle biopsy involves the removal of a small piece of muscle tissue from the vastus lateralis using a sterile hollow needle. The area over the incision site will be carefully cleaned, and a small amount of local anesthetic will be injected into and under the skin. A small, 4 - 5 mm incision will be made in the skin to create an opening for the biopsy needle. The biopsy needle will then be inserted through the incision into the muscle, and a small piece of muscle (\~50 mg) will be removed, and the needle taken out. A medical doctor will perform this procedure. Protein analysis: Western blotting will be used to analyze the abundance of ferritin within small sections of the muscle sample.
Muscle Ferritin
时间窗: At baseline (week 0) and completion of supplementation (week 12)
Muscle collection: The muscle biopsy involves the removal of a small piece of muscle tissue from the vastus lateralis using a sterile hollow needle. The area over the incision site will be carefully cleaned, and a small amount of local anesthetic will be injected into and under the skin. A small, 4 - 5 mm incision will be made in the skin to create an opening for the biopsy needle. The biopsy needle will then be inserted through the incision into the muscle, and a small piece of muscle (\~50 mg) will be removed, and the needle taken out. A medical doctor will perform this procedure. Protein analysis: Western blotting will be used to analyze the abundance of ferritin within small sections of the muscle sample.
次要结局
- Iron-related proteins(At baseline (week 0) and completion of supplementation (week 12))
- Mitochondrial proteins(At baseline (week 0) and completion of supplementation (week 12))
- Whole body aerobic fitness (VO2max)(At baseline (week 0) and completion of supplementation (week 12))
- Single-leg critical power(At baseline (week 0) and completion of supplementaton (week 12))
- Muscle oxidative capacity(At baseline (week 0) and completion of supplementation (week 12))
- Countermovement jump test(At baseline (week 0) and completion of supplementation (week 12))
- Serum iron status(Every four weeks beginning at baseline (week 0) until completion of supplementation (week 12))
- Iron-related proteins(At baseline (week 0) and completion of supplementation (week 12))
- Serum iron status(Every four weeks beginning at baseline (week 0) until completion of supplementation (week 12))
- Whole body aerobic fitness (VO2max)(At baseline (week 0) and completion of supplementation (week 12))
- Mitochondrial proteins(At baseline (week 0) and completion of supplementation (week 12))
- Single-leg critical power(At baseline (week 0) and completion of supplementaton (week 12))
- Muscle oxidative capacity(At baseline (week 0) and completion of supplementation (week 12))
- Countermovement jump test(At baseline (week 0) and completion of supplementation (week 12))
研究者
Martin MacInnis
Associate Professor
University of Calgary