touchRESPIRATORY coverage of ERS 2024:
Although there is limited evidence on the link between interstitial lung disease (ILD) and malnutrition, malnourished patients tend to have shorter survival rates, regardless of disease severity. A late-breaking abstract presented at ERS 2024 titled “Dietetic intervention in malnourished patients with interstitial lung disease (ILD): a pilot trial” investigated whether dietitian involvement could provide meaningful benefits to these patients, potentially laying the groundwork for further research and future clinical guidelines.
In this interview, we speak with Ras Kahai, Respiratory Dietitian at Royal Brompton Hospital, London, UK, and the study’s presenter at ERS 2024, to learn about the study’s rationale, review the key findings, and discuss the future implications of her research in shaping more comprehensive care for ILD patients.
Q1: What impact does malnutrition have on patients with ILD?
Unfortunately, there isn’t much evidence in the area of interstitial lung disease (ILD), particularly regarding nutrition, dietetics, and malnutrition. However, malnutrition is important for patients with ILD because, regardless of disease severity, malnourished patients tend to have a shorter survival. The main reason many patients become malnourished is due to what we refer to as ‘nutrition impact symptoms.’ These symptoms can arise because patients are often in a catabolic state, where their energy requirements are much higher, causing them to burn more calories. Additionally, their appetite might be reduced, they may experience nausea, or they might suffer side effects from medications, such as diarrhoea and nausea. So, it’s usually a combination of symptoms that leads to malnutrition. The most important takeaway is that malnutrition significantly affects survival rates.
Q2: What was the rationale behind the study?
There has never been a research trial specifically looking at the impact of a dietitian on patients with ILD. In my role, I work with various respiratory teams across the country, which is common for most respiratory dietitians. We often have to cover multiple disease groups, as our specialty is quite rare.
I was receiving a large number of referrals but couldn’t meet the demand. My amazing consultant, Professor Renzoni, suggested we conduct a research study to evaluate the impact of specialiserd dietary intervention . The goal was to see if the involvement of a dietician is beneficial for ILD patients, which could lead to further work and potentially inform future guidelines. Since this is the first trial focusing on the role of dietitians in this context, it needed to be a pilot and feasibility study, which is where we started.
The main reason for this research is the significant unmet need. Many patients are seeking dietetic support, likely because it’s one of the few things they have some control over. They can’t control their disease, but they—and particularly their carers—can manage their food and drink intake and how that affects their well-being. So, it’s a combination of patient demand, the lack of research in this area, and the need for more support. That’s why we initiated the first trial, which was kindly funded by the Royal Brompton and Harefield Hospitals charity through a non-medical fellowship.
Q3: What was the methodology of the study?
In terms of methodology, this trial was open only to people with ILD who were either at risk of malnutrition or already malnourished. Since this was the first trial of its kind, we focused on assessing the feasibility of recruitment and retention—essentially, could we even get patients to participate? While we hoped for a positive outcome, it’s always uncertain. You could offer dietitian support, and patients might decline, saying they don’t need it.
We also looked at exploratory secondary outcomes like anthropometrics and well-being. The trial was designed as a 12-week randomized controlled trial. Patients were randomized to one of two groups: those who received personalized dietetic support from me or a control group. It’s worth noting that the control group received more than standard care, which, unfortunately, is often non-existent across the country. They were given a ‘poor appetite’ diet sheet, as it’s common practice in the medical field to hand out leaflets. We thought it would be interesting to compare outcomes, as providing a leaflet is much cheaper and less time consuming than employing a dietitian.
In addition to the leaflet, the control group had contact about their weight at 2, 4, and 8 weeks, which is already more than typical care. They were asked to weigh themselves and received a set of scales. Both groups had their weight monitored, and both intervention and control groups completed questionnaires assessing anthropometrics, food diaries, and other metrics at the beginning and end of the trial. Importantly, there were no significant differences in baseline characteristics between the two groups.
One point to emphasize is that, on average, participants had lost about 8 kg in the 12 months prior to the trial, even though their BMI was technically within the normal range. This suggests that many of these patients might be overlooked because when people think of malnutrition, they often imagine severe cases seen on TV or in other countries. In reality, it’s far more common than we realize, and we may be missing these patients because their malnutrition doesn’t fit the typical image.
Q4: What were the key findings?
The key finding from the study, which was particularly important for the European Respiratory Society (ERS), was that the control group—who received care above the usual standard—continued to lose significant weight, while the group receiving dietetic support saw their weight stabilize. This demonstrated that dietetic input significantly reversed ongoing weight loss in patients with ILD, and this result remained significant even after adjusting for disease severity, BMI, weight, height, demographics, and antifibrotic medications. Interestingly, the trend persisted regardless of whether patients were on antifibrotic medications or not, though the sample size was quite small.
Another finding was that while the dietetic group showed improvement in several gastrointestinal and malnutrition symptoms, these improvements didn’t reach statistical significance after three months, except for constipation, where the dietetic group showed significantly better outcomes than the control group. There was a notable trend in malnutrition scores, with a lower score (indicating better outcomes) in the dietetic group (4.9) compared to the control group (7.4). However, three months wasn’t quite enough time to achieve significance for most symptoms.
One challenge we faced was that many patients were reluctant to complete the questionnaires, which made it difficult to collect data, particularly toward the end of the trial. Like in many trials, patients were more interested in receiving the dietetic support than filling out forms. One factor that may have influenced the results is disease severity. It’s possible that worsening disease symptoms, unrelated to nutrition, could have confounded the symptom data, making it harder to isolate the effects of dietetic support.
Despite these challenges, over 80% of patients in the dietetic group reported feeling better, compared to less than 40% in the control group. We also conducted semi-structured interviews with patients from both groups, and those in the dietetic group reported that the advice they received significantly increased their awareness of their eating habits and helped them make positive changes. It was rewarding to hear positive feedback and to see that patients were not only appreciative of the support but were also implementing the advice in their daily lives.
The primary aim of the trial was to assess the feasibility of recruitment and retention, and we successfully met our target of 40 patients. Notably, we didn’t have a single patient drop out, which was a point of interest during the ERS presentation. While the sample size was small, I think this reflects the fact that patients really valued the dietetic support and saw it as something that could benefit their care. Dietetics may not attract the same level of attention or funding from pharmaceutical companies, but it shows that when you conduct a trial addressing an area of patient need, patients are more likely to stay engaged.
We also demonstrated a high unmet need for dietetic care, with 128 referrals received during the seven-month recruitment window. Ultimately, the most significant finding was that dietetic care was able to reverse ongoing weight loss in ILD patients, although this will need to be confirmed in a larger trial.
Q5: Do you anticipate a follow-up study building on the results of this pilot trial?
Yes, that’s the hope for the future—potentially with Professor Renzoni—to explore a multicenter trial. We’re in the process of writing the manuscript, and it’s definitely something on our radar. We certainly want to consider a multicenter trial.
But, like most good research, this study has raised more questions than answers. For example, as a dietitian, I estimate patients’ energy needs using equations derived from machines like indirect calorimetry. These machines require patients to sit in a hood and breathe, which helps calculate how many calories they’re burning. However, the data we currently use for ILD comes from studies conducted in the 1990s, and idiopathic pulmonary fibrosis (IPF) wasn’t even widely recognized as a diagnosis back then. This highlights how much basic knowledge we’re still missing. For instance, we assume these patients burn more calories than the general population because of factors like lung scarring and inflammation, but no one has actually studied or published data to confirm this.
It’s interesting because we often assume that this information is readily available in the literature, but it’s not. Another area that needs more research is body composition. While it’s great that we saw a significant reduction in weight loss, early research in ILD is showing that muscle mass is perhaps more important than weight. This aligns with findings in other respiratory conditions, where muscle health is critical, particularly because muscles around the lungs and diaphragm help with breathing. If patients enter starvation mode and lose muscle mass, it can have a severely negative impact on their ability to breathe and function.
So, while we definitely want to move forward with a larger trial, there are many smaller but equally important questions that need to be addressed along the way.
Disclosures: Ras Kahai has nothing to disclose in relation to this short article.
Cite: Kahai R. Dietetic intervention in malnourished patients with interstitial lung disease. touchRESPIRATORY, November 6, 2024.
This content has been developed independently by Touch Medical Media for touchRESPIRATORY. It is not affiliated with the European Respiratory Society (ERS). Unapproved products or unapproved uses of approved products may be discussed by the faculty; these situations may reflect the approval status in one or more jurisdictions. No endorsement of unapproved products or unapproved uses is either made or implied by mention of these products or uses by Touch Medical Media or any sponsor. Views expressed are the speaker’s own and do not necessarily reflect the views of Touch Medical Media.
