Weight loss and muscle atrophy in patients with chronic obstructive pulmonary disease are linked with increased morbidity and mortality. Yet malnutrition remains under-diagnosed and undertreated,
The World Health Organisation defines chronic obstructive pulmonary disease (COPD) as a lung disease characterised by chronic obstruction of lung airflow that interferes with normal breathing and is not fully reversible. It is an under-diagnosed, long-term and life-threatening disease.
In Australia, it is estimated that one in seven people over the age of 40 has COPD. Furthermore, COPD was the fifth leading cause of death in 2017.
While weight loss has long been considered an inevitable consequence of the disease, there’s growing interest in the area of diet and the importance of managing malnutrition.
Several studies have shown malnutrition in COPD results in significant negative outcomes. The consequences include higher mortality and morbidity, increased healthcare costs, longer hospital stays and frequent re-admissions, reduced muscle strength and reduced respiratory muscle function.
According to the 2020 Global Strategy for Prevention, Diagnosis and Management of COPD, low BMI, in particular low fat-free mass (lean tissue), is linked to poorer outcomes in people with COPD. Yet, nutritional supplementation in malnourished COPD patients can support notable weight gain and improvements in respiratory muscle strength.
Causes and prevalence of malnutrition in COPD
While data on the prevalence of malnutrition in COPD patients in Australia is limited, a study by Jenna Stonestreet suggested that up to 60% of COPD inpatients at the Prince Charles Hospital in Queensland are malnourished. The small-scale study revealed that of the patients admitted with a COPD exacerbation, 42% were malnourished and 38% were at risk of malnutrition.
While not specific to COPD patients, the 2010 Australian Nutritional Care Survey identified 30% of hospitalised patients as malnourished, with 6% of patients being severely malnourished.
Peter Collins, senior lecturer in nutrition and dietetics at Griffith University and accredited practising dietitian with the Dietitians Association of Australia, explains, “The primary factors everyone thinks about with regards to the causes of malnutrition are breathlessness and limited mobility. As a result, these may impact their metabolism, appetite, ability to prepare food and their capacity to meet their nutritional needs.”
According to the Managing Malnutrition in COPD guidelines, the causes of malnutrition are varied but include the following:
- disease effects, e.g. breathlessness, anorexia, inflammation;
- psychological factors, e.g. motivation, apathy, depression;
- social factors, e.g. social isolation, death of a partner, lack of practical support;
- environmental factors, e.g. living conditions, access to shops;
- increased nutritional requirements, e.g. energy, protein; and
- medication: inhaled therapy and oxygen therapy, e.g. taste changes, dry mouth; frequent or prolonged use of corticosteroids adversely affecting bone density and muscle mass (lean tissue).
“The disease also has periods of exacerbation where the person may develop a chest infection that results in hospitalisation. This can increase their nutritional requirements but compromise their nutritional intake.
“Malnutrition and COPD is bidirectional; the disease impacts nutritional status but we also know that nutritional status influences disease severity,” adds Mr Collins.
Medication and malnutrition
Consultant clinical pharmacist Debbie Rigby says, “Malnutrition and low body weight are highly prevalent among patients with COPD, and both contribute to patient morbidity and mortality. There are several factors that can lead to poor nutritional status in patients with COPD; this includes poor eating habits, sedentary lifestyle, smoking, as well as medication use.
“Inhaled therapies, such as long-acting antimuscarinic agents (LAMAs), are the cornerstone of COPD management. When used regularly and effectively, these therapies are very effective in controlling lung function and symptoms. However, they may impact negatively on oral health and nutrition.
“Inhaled muscarinic antagonists (SAMAs and LAMAs) can cause dry mouth, which can negatively impact food and liquid intake, cause denture troubles, and lead to difficulty with taste and swallowing—all of which can result in dental decay.
“Prolonged dry mouth also increases the risk of oral thrush, which may also be caused by inhaled corticosteroids. Oral thrush can lead to mucosal lesions, which have a negative impact on energy intake and may subsequently worsen nutritional status.”
She adds, “Dry mouth can also be seen with over-reliance on short-acting beta2-agonists, such as salbutamol. Prolonged use can reduce salivary flow by around one-third. Regular assessment of device technique and use of spacers with metered-dose inhalers is critical to minimise oropharyngeal deposition.
“Early detection and management of dry mouth is important to prevent these adverse dental effects. Pharmacists can suggest saliva substitutes, although correcting the problem should be the priority. This may alleviate long-term complications and improve quality of life for COPD patients.”
Pharmacy-based nutritional screening
The average Australian visits a pharmacy 14 times per year, which offers great potential to screen for malnutrition and provide practical nutritional advice to patients.
Pharmacists and their staff can discuss any reservations an individual might have, particularly in regards to weight gain, and also consider the patient’s ability to implement the dietary advice they’ve been given by other healthcare professionals.
“In my experience, community pharmacists tend to play a limited role in nutritional screening. However, community pharmacists know their regular patients, plus patients with COPD are likely to visit the pharmacy at least monthly. Observing sudden or gradual weight loss can lead into a conversation with the patient about the importance of optimal nutrition, but any information provided needs to be evidence-based,” says Ms Rigby.
Mr Collins says, “Perhaps during the annual flu vaccine season dieticians could team up with local pharmacists or GPs to combine the vaccine with nutritional screening.
“Alternatively, if a pharmacist notices a patient has COPD and they’ve been prescribed antibiotics and prednisone to treat a chest infection or an exacerbation, this might be the perfect time to screen for malnutrition.”
Contrary to the longstanding belief, weight loss is not an inevitable part of COPD disease progression.
The NICE clinical guideline for COPD (2018) state the following:
- The BMI for people with COPD should be calculated. The normal range for BMI is 20 to < 25kg/m2.
If the BMI that is abnormal (high or low) or has changed over time, the person should be referred for dietetic advice.
- Particular attention should be paid to changes in weight in older people, especially if the change is more than 3kg. Note: Weight change should also be considered in terms of percentage change from usual weight. Involuntary weight loss of more than 5% during the last 6 months is considered clinically significant.
- If the BMI is low (less than 20kg/m2)
- nutritional supplements can be provided to increase the person’s total calorific intake. They should also be encouraged to exercise to support the effects of nutritional supplementation.
In the absence of height and weight being measured or recalled by the patient, the following indicators can be used collectively to estimate the risk of malnutrition:
- thin or very thin in appearance, or loose fitting clothes/jewellery;
- history of recent unplanned weight loss;
- changes in appetite, need for assistance with feeding or swallowing difficulties affecting ability to eat and drink; and
- a reduction in current dietary intake compared to ‘normal’.
“There’s a lot of evidence for oral nutritional supplements but the stage we’re at currently is identifying how to increase patients’ lean body mass, which is a real challenge using nutrition alone.
“We know that we can treat malnutrition with dietary counselling from a dietitian and the addition of nutritional supplements, but any weight the patient gains tends to be fat mass. We need nutritional support combined with exercise in order to increase lean body mass,” explains Mr Collins.
“Most of the data is based on ready-to-drink oral nutritional supplements so we have been looking into powdered supplements. We found adherence to the powdered supplements was less than 50%, which is quite significant when you consider that adherence to oral nutritional supplements that are ready to drink can be over 90%.
“We need to understand which patients need ready-to-drink supplements and which ones can be relied upon to take the powdered supplements. There could be a barrier in that if you’re not motivated or you’re severely impacted by your respiratory disease, you won’t or can’t make the supplement up yourself. In this case if you can grab a supplement that’s already made up that might be a better option.”
“Access to dietitians is very limited; there simply aren’t enough dietitians in Australia to see all the patients with COPD. So there is a huge role for community pharmacists to encourage patients to self-screen for malnutrition while they’re in the pharmacy,” says Mr Collins.
“Studies have shown patients are capable of screening themselves for malnutrition (using the MUST tool). In Australia we use the Malnutrition Universal Screening Tool (MUST) or the Malnutrition Screening Tool (MST).
“When you look at the average COPD patient’s journey through the healthcare system, most of it takes place in the community. So while a dietician in the hospital might get to see the patient once or twice a year, the GP and the pharmacist see the patients significantly more often. This makes them better placed to screen and identify those patients at risk of malnutrition.”
To help pharmacists understand patients’ dietary intake and nutritional status, the following questions can be used:
- How is your appetite?
- Are you managing to eat as well as you usually do?
- Have you noticed any changes in your weight? (For example, clothes may feel looser. Friends or family members may have commented on your appearance.)
- Have you noticed any changes to your body shape? (For example, any changes in muscle strength or your ability to grip things.)
- Do you have any concerns about your food intake and diet?
Mr Collins says there are inroads being made in the acute setting, when patients with COPD are hospitalised. However, we need to work out how to leverage this activity in the in-patient setting in the community, once patients have been discharged.
“One of the barriers is that there’s no system to support the transfer of nutrition information to the community. Pharmacists could certainly play an important role in this area.
“Those identified at risk can be offered an oral nutritional supplement and referred to their GP. There are also patient leaflets available that can be useful”.
These leaflets can be accessed here
COPD and COVID-19
Patients with COPD should be encouraged to take precautions to protect themselves against all respiratory illnesses. This includes staying up to date with their flu and pneumococcal vaccines.
Certainly, social restrictions may make it difficult for some people to access their usual care and medicines. Pharmacists can reiterate the advice of Lung Foundation Australia, which includes advising patients of the following:
- Don’t stop taking your medication unless advised by a treating doctor.
- Make sure you have an adequate supply of your daily and emergency medications.
- Check the dates of your prescriptions to ensure they are current.
Pharmacists can also take action to ensure patients using inhaled medicines have the correct technique and, if need be, organise home delivery of medicines and assist people to access health services via telephone and other available applications.
To offer an extra level of information and support during the COVID-19 pandemic, Lung Foundation Australia has introduced the Lung Support Service. It is a free texting service for people with COPD that can be accessed from the comfort of home.
Individuals (must be aged over 18 years and have access to a mobile phone) can register for the service via the Lung Foundation Australia website.