Iron deficiency is common in older patients and treatment can make a “massive difference” to their quality of life, including their cognitive function, mobility, and potential risk of hospitalisation, says Clinical Associate Professor Pradeep Jayasuriya, GP and founder of the WA Iron Centre – a Perth private clinic that manages people with iron deficiency and iron deficiency anaemia.

Iron deficiency common but not normal in older patients

Iron deficiency is the precursor to anaemia, which is “a big contributor to both mortality and morbidity and quality of life in our older adults,” Associate Professor Jayasuriya says, noting anaemia prevalence rises sharply with age.

“In the normal population, it’s about two to three per cent. And it goes up to about 20 per cent by the time you’re 80,” he says.

While data on iron deficiency in older people is limited, “the rule of thumb is you multiply the prevalence of anaemia by three, and that gives you your prevalence for iron deficiency.”

It is a particular problem in aged care, he adds, noting one Adelaide study that found a prevalence of about 80% among residents.

GPs are skilled at picking up small changes that could indicate iron deficiency, such as reduced cognitive function and increased frailty, he says.

“They’re not as sharp. They don’t walk into your room as quickly as they ought to. Those little subtle things that no ED department, no specialist would pick up on, but you would because you know these people so well.”

Importantly, iron deficiency and anaemia are not a normal part of ageing, he stresses.

Assessing iron deficiency

Testing is essential in symptomatic patients, Associate Professor Jayasuriya says, and should include a full blood count, iron studies and CRP at a minimum.

Iron studies are needed because a lot of older patients have inflammation, he explains.

“Ferritin is an acute phase reactant, so it goes up in inflammation. So the ferritin on its own is not going to be sufficient for you to determine whether they’re iron deficient or not.”

A fasting blood sample is recommended to get an accurate serum iron, which gives you an accurate transferrin saturation, he says.

“That is an important parameter when you’re assessing iron stores.”

Results must be interpreted with care, he adds.

“When you get your pathology results, don’t look at the bold highlighted bits and don’t look at the comment down the bottom. This is not just a game of numbers. You have to make your own interpretation because it isn’t that straightforward in older people.”

Regarding iron studies, he looks at ferritin first.

“If that’s under 30, they’ve got absolute iron deficiency. That’s the game set and match. You don’t need to look at anything else.”

If ferritin is up to 100, look at transferrin saturation. If under 20, this could signify iron deficiency, he says.

In the context of heart failure, iron deficiency is defined as: 

• ferritin of less than 100 (regardless of transferrin saturation) 

• ferritin between 100 and 300 and a transferrin saturation of less than 20.  

He recommends looking at haemoglobin next to determine if your patient is anaemic, noting there is significant debate about what is normal in older people.

“Studies that came up with reference ranges didn’t have anyone over the age of 65 so they’re likely to be inaccurate,” he says, suggesting you draw on historical patient data and symptoms to interpret results.

“Also, when you come to treatment, if they get a good haemoglobin response, then you know they were actually anaemic when you treated them,” he adds.

Investigating the cause

Iron deficiency is not a diagnosis and further investigation is warranted.

“Somewhere in your records, you must ascribe a cause to it,” Associate Professor Jayasuriya says.

Common causes in the older population include:

Poor nutrition

Don’t assume someone’s nutrition is adequate, Associate Professor Jayasuriya says.

“You need to go through what people are actually eating and also corroborate that with their carers, because what people think they might be having and what they are actually having can be two entirely different things.”

Poor absorption

Although coeliac disease will usually already be diagnosed in this group, coeliac serology is recommended as part of the initial work up for iron deficiency anaemia, Associate Professor Jayasuriya says.

Helicobacter is worth routinely testing for, using serology as a screening test, and progressing to a breath test for confirmation, he says.

“Helicobacter can affect absorption, but it can also cause gastritis and bleeding, which can also lead to iron deficiency.”

Proton pump inhibitors (PPIs) also cause poor absorption, he says, “and that’s why oral iron doesn’t work if they’re taking a PPI.”

Blood loss

“In the older population, the commonest bleeding source is the gut. You’ve got ulcers, you’ve got polyps, you’ve got angiodysplasia being the common causes,” Associate Professor Jayasuriya says.

However, deciding how far to chase the source of blood loss is nuanced in this group.

“The guidelines would say you have to do an endoscopy and colonoscopy routinely on anyone who’s got iron deficiency with anaemia over the age of 50. However, in older people, that question becomes a little more complicated,” he says.

“You have to factor in other considerations. If they’re very frail, if they’re very elderly, as to whether they’re fit enough to have a colonoscopy or endoscopy.”

It will largely depend on the rate of blood loss and “how easy or difficult it is to find that bleeding source,” he says.

For example, “If they drop their haemoglobin really rapidly in three months, you might say, listen, it looks like there’s an active bleeding source there. We need to find it,” he says.

Angiodysplasia, which he likens to a “nosebleed in the gut”, can be particularly tricky to track down.

“Some of that could be hiding in the small bowel. And how far do you chase that? Or do you just accept the fact that they’re oozing and keep repleting their iron? There aren’t any rules around the right or wrong answers to that.”

He recommends discussing these issues with patients and guiding them towards a decision.

Anticoagulants can also contribute to blood loss, but patients may need to take them, he notes.

“It’s essentially balancing risk and benefit and as one gets older the benefit diminishes and the risk increases, so you have to constantly review that equation.”

He suggests conducting a medication review at least annually and discussing how best to manage anticoagulants with the patient’s cardiologist and gastroenterologist.

Treatment options: oral or IV?

Along with addressing the cause, you need to replenish iron stores—and there are only two ways to do this, Associate Professor Jayasuriya says.

“You can’t do it with diet. It’s impossible to get enough iron-rich food to fill up the tank. And intramuscular iron is now really an outmoded and dangerous form of treatment. So you’re left with oral and IV. And they’re both good options.”

Oral iron is usually first line, he says, noting it generally takes at least three to six months to fill the tank and requires good medication adherence.

It must be taken on an empty stomach away from other medications, which can be difficult for older patients taking multiple drugs.

“The other issue is 40 percent of people who take oral iron would either get constipation, nausea or diarrhoea. So the incidence of adverse events is considerable, especially the constipation is problematic.”

IV iron

One benefit of intravenous iron is a faster response.

“It’s one visit and you can fill that tank up quickly,” he says.

Intravenous delivery also helps overcome functional iron deficiency related to excess hepcidin, he adds.

“Hepcidin is like the master regulator for iron metabolism,” he explains. “When you’ve got high levels of hepcidin, it blocks the utilisation of iron at an absorption level in the gut, but also at a cellular level, it stops the storage cells from releasing their iron.”

“You might have enough iron stores, but the iron can’t be mobilised for erythropoiesis and other useful functions. And the only way to bypass that hepcidin block is with intravenous therapy.”

Intravenous therapy is considered first line in heart failure, he adds.

What are the risks?

A downside is the risk of adverse events, including some rare but serious ones.

Anaphylaxis risk is about one in 250,000, he says.

Clinically significant hypophosphatemia is rare but tends to be more frequent in older people, especially if they have comorbidities.

Older people with fragile veins can also be at higher risk of staining.

The risk of adverse events, especially minor ones such as headache and nausea, may be mitigated by managing the speed of iron delivery, he says.

“If you’ve got a pump, you can control the rate and trickle it in really slowly. And our personal experience is the slower the rate, the less side effects, and especially in older people that’s worthwhile doing.”

He also recommends having a nurse stay with the patient, and making sure they are well hydrated before and after the infusion.

Follow up and managing complications

Iron studies should be repeated six weeks after treatment, he says.

This tells you whether their iron tank is filled and provides a baseline for monitoring.

“If the iron is dropping quickly, you know that there’s active bleeding you may not have been aware of. Or if you thought you’ve treated their problem and their iron still continues to fall, then you know that there’s another pathology you need to look for.”

You can generally test again six months later, or earlier in patients with more acute bleeding.

He only tests for hypophosphatemia if they have symptoms suggestive of it, which include severe muscle pain, fatigue, and malaise.

“It’s quite distinctive,” he says. “And it’s just a matter of checking their phosphate levels.”

Key messages: 

• Iron deficiency is common in older patients but not a normal part of ageing. 

• Assessment should include a full blood count, iron studies and CRP. 

• Assessment when ferritin is >30 requires clinical judgment, considering symptoms, presence or absence of inflammation and T saturation. 

• Patients with heart failure with ferritin <100, or ferritin between 100 and 300 and transferrin saturation <20, are considered iron deficient. 

• The cause needs to be investigated and documented. 

• Treatment options are oral or IV iron and each has pros and cons.