Simple Nutritional Score Emerges as Strong Predictor of Survival in PPF

A new study reports that a routine, low-cost nutritional assessment tool may offer a powerful way to predict survival in patients with progressive pulmonary fibrosis (PPF), a life-shortening condition with limited treatment options and high uncertainty around disease trajectory.

These new findings, published in BMC Pulmonary Medicine, suggest that incorporating the Controlling Nutritional Status (CONUT) score into the standard assessment of patients with PPF can both help improve risk stratification and aid in clinical decision-making.

Despite antifibrotic therapy, PPF remains associated with poor survival, and predicting which patients will deteriorate remains a major challenge. At the same time, malnutrition has been increasingly linked to outcomes in chronic lung disease, such as chronic obstructive pulmonary disease,² but most prior research has focused on indirect measures such as body mass index (BMI), which can be unreliable due to variations in factors such as body composition.

“While BMI has been frequently used to assess nutritional status, its limitations due to ethnic and regional variability reduce its predictive power,” explained the researchers. “For instance, Nakatsuka et al. found an association between annual weight loss and mortality in Japanese patients, but baseline BMI had no significant prognostic value.”

CONUT score offers an alternative approach by using 3 routinely available laboratory parameters—serum albumin, total cholesterol, and lymphocyte count—to quantify nutritional and immune status objectively. Unlike BMI-based tools, CONUT reflects protein reserves, caloric depletion, and immune competence, all of which may worsen during chronic respiratory decline.

The investigators conducted a retrospective analysis of 58 patients treated at a single tertiary center in Turkey. All patients had at least 2 indicators of disease progression within the previous year, and most patients were receiving antifibrotic treatment, 82.8% with nintedanib and 17.2% with pirfenidone.

Patients were grouped into 3 categories based on their CONUT scores: normal (0-1), mild malnutrition (2-4), and moderate malnutrition (≥5). Most patients (69%) fell in the normal range, while 27.6% had mild and 3.4% had moderate malnutrition.

At 6 months, forced vital capacity (FVC) decline was significantly more common in patients with mild or moderate malnutrition than in those with normal nutritional status (75% and 100% vs 30%; P = .017). Total cholesterol levels also tracked with worsening nutritional status, emphasizing metabolic depletion as a contributing factor. Importantly, corticosteroid use—present in nearly half the cohort—did not influence survival.

Survival analysis revealed a notable separation between nutritional groups. Patients with moderate malnutrition had the steepest decline in cumulative survival, followed by those with mild malnutrition, while patients with normal scores demonstrated the most favorable prognosis. The log-rank test confirmed a significant difference in survival across categories (P = .024).

Cox regression analysis further demonstrated that moderate malnutrition was independently associated with mortality, with a hazard ratio of 25.92 (95% CI, 1.52-40.65; P = .024).

“The wide confidence intervals observed, however, highlight potential model instability due to the small sample size, and the results should be interpreted cautiously,” noted the researchers.

BMI, by contrast, showed no prognostic value, a finding consistent with previous studies, including work demonstrating that weight loss over time, rather than baseline BMI, better predicts mortality in fibrotic ILD.

The study reinforces that malnutrition in PPF is not merely a marker of advanced disease but may actively contribute to clinical decline through systemic inflammation, increased respiratory muscle burden, hypoxemia, and reduced functional reserve, wrote the researchers. They note that nutritional deterioration may begin early and progress silently, making proactive assessment critical.

Still, the researchers acknowledge limitations: the single-center retrospective design, small cohort size, especially within the moderate malnutrition category, and absence of data on statin use, which could influence cholesterol-based scoring. They emphasized the need for larger, prospective, multicenter validation and for exploring whether nutritional intervention can alter disease course.

References

1. Akkurt ES, Ozdemirel TS, Ozyurek BA, Ensarioglu K, Birben OD, Zenbilli E. CONUT score as a prognostic biomarker in progressive pulmonary fibrosis: a simple tool for clinical risk stratification. BMC Pulm Med. Published online November 18, 2025. doi:10.1186/s12890-025-04013-0

2. Feng, M, Liu, Y, Li Q. et al. Association between geriatric nutritional risk index and adverse outcomes in critical ill patients with chronic obstructive pulmonary disease: a cohort study of 2824 older adults. BMC Pulm Med. 2024;24:634. doi:10.1186/s12890-024-03454-3