Unintended weight loss in IPF linked to higher risk of death: Study
More attention to nutrition among patients urged in research, practice
Individuals with idiopathic pulmonary fibrosis (IPF) who experience unintended weight loss are at significantly higher risks of being admitted to the hospital or dying within one year, a Danish study reported.
Specifically, IPF patients with unintended weight loss were found to have a nearly 30 times higher risk of death, and were almost 16 times more likely to be hospitalized.
These findings highlight that “higher attention regarding research and practice should be given to nutritional and functional status in pulmonary fibrosis,” according to researchers.
The study, “A one-year follow-up study in patients with idiopathic pulmonary fibrosis regarding adverse outcomes to unintended weight loss,” was published in the journal Nutrition.
Investigating unintended weight loss among patients
People with IPF often experience weight loss, likely due to a decrease in calorie intake accompanied by heightened inflammation. Many patients with the disorder are found to have poor nutrition.
Malnutrition associated with pulmonary fibrosis (PF) results in body changes, as well as impaired physical and mental function, which are associated with higher hospitalization and mortality rates.
Although unintended weight loss has been found to be associated with survival rates in idiopathic PF patients, the burdens associated with IPF-related nutrition problems have not been thoroughly investigated.
Now, researchers in Denmark explored the link between body weight, weight loss, and signs of sarcopenia — loss of muscle mass and strength — and hospital admissions and mortality in a group of IPF patients. The team, from the Aalborg University Hospital, also assessed the rate of pulmonary rehabilitation among these patients, as well as the prevalence and associations of signs of sarcopenia, as measured by the SARC-F questionnaire.
Individuals with IPF being followed at an outpatient clinic were recruited for the study while waiting for a clinical consultation. At the study’s start, or baseline, participants filled out a questionnaire, and their height and body weight were measured.
One year later, the participants were interviewed by phone to collect follow-up data regarding their current body weight, sarcopenia, and pulmonary rehabilitation participation. Their medical records also were analyzed.
In total, 98 patients were included at baseline, and data were available for 91 of them after one year of follow-up. Two patients died during the study period and five were lost to follow-up.
The median body-mass index (BMI) – a ratio of height to weight that’s used to estimate body fat – at baseline was 27.8 kilograms per square-meter (kg/m2), and 27.4 kg/m2 at the one-year follow-up.
The proportion of patients with unintended weight loss was higher at follow-up than it was at baseline (13.2% vs. 10.2%.) Mean weight loss increased from 9.1 kg (around 20 pounds) at baseline to 11.8 kg (around 26 pounds) at the one-year follow-up.
At the study’s start, the patients’ hospitalization rate for the prior three months was 26.5%. Nearly one-third of the patients (30.8%) were admitted to the hospital due to IPF, and 69.2% for other reasons. At follow-up, 39.6% of the patients had been admitted to the hospital. There was a median of two hospitalizations per year for the participants.
Patients who already lost weight at [the study’s start] were subject to higher risk of mortality and hospital admissions within the year.
From the 91 patients with one-year data, 11 (12.1%) were offered pulmonary rehabilitation and four (36.4%) went ahead and participated in the rehabilitation program.
A total of 19 patients (20.9%) were at risk of developing sarcopenia, as shown by a SARC-F score of four or higher. Scores equal to or greater than four in the SARC-F questionnaire are predictive of sarcopenia and poor outcomes.
Compared with patients with low SARC-F scores, those with higher scores who were at an increased risk of developing sarcopenia were more frequently offered pulmonary rehabilitation (5.99 times more often).
Unintended weight loss linked to poor outcomes
Statistical analyses also revealed that being female, older (age 71 and older), having additional diseases or comorbidities, and experiencing unintended weight loss at baseline all were variables that were independently associated with experiencing unintended weight loss at follow-up.
Importantly, patients with unintended weight loss at baseline were at a higher risk — 29.81 times higher — of death, and were 14.68 times more likely to be hospitalized.
Obese patients — those with a BMI of 30 kg/m2 and higher — had more coexisting medical conditions and a tendency for being admitted to the hospital more frequently than those with a lower BMI. The rate of hospitalizations was 3.8 times higher for obese patients, the data showed. Age was found to be a factor impacting the association between unintended weight loss at follow-up and sarcopenia.
At follow-up, obese IPF patients were 5.10 times more likely to be offered pulmonary rehabilitation, and patients at risk of sarcopenia (SARC-F score of four or higher) were 6.51 times more likely.
“Unintended weight loss frequently occurs in pulmonary fibrosis outpatients and increases in [up to one year] of follow-up,” the researchers wrote, adding, “Patients who already lost weight at baseline were subject to higher risk of mortality and hospital admissions within the year.”
The scientists said these findings highlight the need for research into unintended weight loss in IPF patients.
“Based on this study, [unintended weight loss], high BMI, body composition, and a low degree of physical rehabilitation participation, including a systematic approach to tertiary rehabilitation, should be the focus of further investigations,” the researchers concluded.