Impact of Nutritional Status on Pulmonary Function in Pediatric Cystic Fibrosis: A Retrospective Multicenter Study from Upper Egypt

<b>Aim:</b> This study aimed to evaluate the nutritional status of children with cystic fibrosis (CF) and investigate the correlation between malnutrition and the decline of pulmonary function in this population. <b>Methods:</b> We retrospectively analyzed the clinical data of children with CF admitted to four large tertiary centers in Upper Egypt. We compared clinical characteristics among children with different nutritional statuses and evaluated the correlation between malnutrition and pulmonary functions. <b>Results:</b> A total of 104 children with CF, including 54 males (52%), aged 3 to 18 years, were analyzed. Respiratory symptoms were present in all cases (100%). Malnutrition was observed in 72% (75/104) of the participants, with affected children exhibiting significantly lower body weight and serum albumin levels. Pulmonary function tests showed that vital capacity (VC) and the predicted values for forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), FEV₁/FVC, and expiratory flow at 25%, 50%, and 75% of FVC were all lower in the malnourished group compared to children with normal nutrition. Correlation analysis demonstrated that the body mass index (BMI) Z-score was positively correlated with these pulmonary function indicators. <b>Conclusions:</b> Malnutrition is highly prevalent among Egyptian children with CF and is associated with decreased pulmonary function. Improving nutritional status may enhance lung function in this population.