Association of nutritional indicators and mortality in idiopathic pulmonary fibrosis: a systematic review and meta-analysis

The association between nutritional indicators and mortality in idiopathic pulmonary fibrosis (IPF) remains unclear. This systematic review and meta‑analysis aimed to comprehensively evaluate the relationship between various nutritional indicators and mortality risk in IPF patients. PubMed, Embase, Web of Science, Cochrane Library, Ovid Emcare and Ovid Nursing Database were systematically searched up to February 1, 2026. Cohort studies reporting associations between nutritional indicators and mortality in IPF were included. For outcomes eligible for meta-analysis, pooled hazard ratios (HRs) and odds ratios (ORs) were synthesized. Nutritional indicators assessed included anthropometric measurements (Body mass index (BMI), weight loss), body composition (muscle mass, sarcopenia, fat‑free mass index (FFMI), fat indices), nutritional risk scores, and biochemical markers (serum albumin). Leave‑one‑out sensitivity analysis and Egger’s test for publication bias were performed. A total of 49 studies involving 30,028 IPF patients from 15 countries were included. BMI was associated with mortality (HR = 0.94, 95% CI: 0.91–0.97, I²=70.6%); subgroup analysis showed that low BMI (< 18.5 kg/m²) was associated with increased mortality (HR = 2.30, 95%CI: 1.10–4.77, I²=64.5%). Weight loss was also related to mortality (HR = 2.27, 95% CI: 1.83–2.81, I²=0.0%; OR = 1.70, 95% CI: 1.24–2.35, I²=32.2%). Regarding muscle mass, erector spinae muscle cross-sectional area (ESM_CSA), sarcopenia and FFMI were associated with mortality (HR = 0.96, 95%CI: 0.93–0.98, I²=0.0%; HR = 2.08, 95%CI: 1.34–3.22, I²=0.0%; HR = 0.63, 95%CI: 0.48–0.82, I²=0.0%). Fat‑related indices remained inconclusive due to limited data. Nutritional risk scores and serum albumin were related to mortality (HR = 1.71, 95% CI: 1.27–2.29, I²=0.0%; HR = 0.90, 95% CI: 0.85–0.94, I²=0.0%). According to GRADE assessment, the certainty of evidence was moderate for weight loss, ESM_CSA, sarcopenia and nutritional risk scores; low for FFMI and serum albumin; and very low for BMI and erector spinae muscle quality index (ESMI). BMI, weight loss, ESM_CSA, sarcopenia, FFMI, nutritional risk scores and serum albumin were associated with mortality risk. Further prospective studies are needed to validate their prognostic utility. The review protocol was prospectively registered in PROSPERO ( CRD420261364663).