Dietary Protein Intake, Normalized Handgrip Strength, and Gastrointestinal Symptoms in Stable Lung Transplant Recipients: A Cross-Sectional Study.

BACKGROUND & AIMS: Lung transplant recipients are at risk for nutritional impairment and reduced muscle function, but the clinical correlates of inadequate protein intake remain unclear. This study examined dietary protein intake and its associations with normalized handgrip strength, body composition, gastrointestinal symptoms, and laboratory-based nutritional markers in stable adult lung transplant recipients. METHODS: This single-center cross-sectional study included 78 recipients undergoing scheduled follow-up at least 6 months after transplantation. Dietary intake was assessed by a registered dietitian using a 24 h recall. Recipients were classified as low-protein (<1.0 g/kg ideal body weight [IBW]/day) or sufficient-protein (≥1.0 g/kg IBW/day). Handgrip strength was normalized to heightˆ0.85, and gastrointestinal symptoms were graded using the Common Terminology Criteria for Adverse Events. RESULTS: Thirty-eight recipients (48.7%) were classified as low-protein and 40 (51.3%) as sufficient-protein. The low-protein group had lower energy intake (25.4 vs. 29.9 kcal/kg IBW/day, p < 0.001) and normalized handgrip strength (15.7 vs. 19.5 kg/mˆ0.85, p = 0.019), whereas appendicular skeletal muscle index did not differ between groups. Protein intake correlated positively with normalized handgrip strength (Spearman rho = 0.326, 95% CI 0.100-0.520, p = 0.004). Any gastrointestinal symptom was more frequent in the low-protein group (39.5% vs. 12.5%, p = 0.009), while laboratory-based nutritional markers were similar. CONCLUSIONS: Lower protein intake was associated with reduced normalized handgrip strength and more frequent gastrointestinal symptoms, but not with lower muscle mass or abnormal laboratory-based nutritional markers.