Lecture 15 - Iron deficiency in athletes

Question 1

What is iron deficiency?

Answer 1

depletion of iron rtores and restriction of iron supply

Question 2

What gets reduced with iron deficiency?

Answer 2

• oxygen transport capacity
• oxidative capacity at the cellular level

Question 3

What are the 4 iron containing proteins?

Answer 3

1. ferritin
2. transferrin
3. hemoglobin
4. myoglobin

Question 4

What is the purpose of ferritin?

Answer 4

iron storage protein

Question 5

What is the purpose of transferrin

Answer 5

iron binding protein

Question 6

What are is the iron containing protein in RBCs?

Answer 6

hemoglobin

Question 7

What is the iron containing protein in muscles?

Answer 7

myoglobin

Question 8

Where is ferritin found?

Answer 8

liver, spleen, bone marrow

Question 9

Where is transferrin produced?

Answer 9

liver, brain, testes

Question 10

What does transferrin do?

Answer 10

transport iron in blood

Question 11

What does hemoglobin do?

Answer 11

carries oxygen from lung to tissues and return carbon dioxide

Question 12

What does myoglobin do?

Answer 12

transports oxygen to mitochondria of muscle cells

Question 13

What does serum ferritin levels reflect?

Answer 13

amount of iron stored in the liver, spleen and bone marrow

Question 14

What is the iron stores in male and females?

Answer 14

males: 55 mg/kg
females: 45 mg/kg

Question 15

What are the 3 iron deficiency stores?

Answer 15

1. pre-latent - iron storage depletion
2. latent - iron deficiency erythropoiesis
3. anemia

Question 16

What characaterizes each iron deficiency stage?

Answer 16

depletion - low serum ferritin, normal HB
- iron stores of liver, spleen and bone marrow are depleted
erythropoiesis -** low serum ferritin, normal HB**
- erythropoiesis is impaired
- iron supply to cells is reduced
anemia - low serum ferritin, low HB
- HB synthesis falls

Question 17

What is the most sensitive and specific test for estimation of total iron body stores?

Answer 17

serum ferritin

Question 18

What is sensitivity?

Answer 18

correctly identify individuals who have a specific disease ( high sensitivity means few false negatives)

Question 19

What is specificty?

Answer 19

corrrectly identify individuals who do not have a specific disease (high specificty meanse few false positives)

Question 20

What is considered anemia for males and females?

Answer 20

low ferritin AND HB

males: <130 g/L (HB)
females: <120 g/L (HB)

Question 21

What ferritin level warrants investigation?

Answer 21

< 35 ug/L

Question 22

What are the signs and symptoms?

Answer 22

• low energy/fatigue
• dizziness
• shortness of breath
• poor athletic performance
• weakness
• plae skin
• lightheaded
• cold hands and feet

Question 23

Who is at risk?

Answer 23

• females
• endurance athletes
• low energy availability/REDs
• athletes with disordered eating
• vegan and vegetarian diet
• medical conditions

Question 24

What are the exercise-induced mechanisms for iron loss?

Answer 24

• hemolysis (destruction of RBC)
• hematuria (blood in urine)
• sweating
• gastrointestinal bleeding
• injuries

Question 25

What are the 3 treatament options?

Answer 25

1. supplements
2. iron rich diet (lena meats, green leafy vegetables, fortified cereals)
3. intravenous iron (if cann tolerate or don’t respond to oral iron)

Question 26

Do athletes need more iron than non-athletes?

Answer 26

Yes, 30-70% more

Question 27

How much iron do pre-menopausal women need?

Answer 27

15 - 18 mg/day

Question 28

How much iron do vegan/vegetarian women need?

Answer 28

33 mg/day

Question 29

How much iron do pregnant women need?

Answer 29

27 mg/day

Question 30

How much iron do men need?

Answer 30

8-11 mg/day

Question 31

How much iron do vegan/vegetarian men need?

Answer 31

14 mg/day