Prevalence of Overweight and Obesity in the Era of CFTR Modulators in Patients with Cystic Fibrosis

<b>Background/Objectives</b>: Cystic fibrosis (CF) is a genetic disorder historically associated with malnutrition. The advent of CF transmembrane conductance regulator (CFTR) modulators and improved pulmonary outcomes have coincided with increased body mass index (BMI). This study aims to evaluate the prevalence of overweight/obesity among children with cystic fibrosis and associated comorbidities. <b>Methods</b>: A retrospective chart review assessed patients with CF (2-23 years of age). Data collected included demographics, CF genotype, anthropometric measurements, pancreatic function, medication history, and any comorbid diagnoses. BMI categories were defined as: underweight (<5th percentile), normal weight (5th-85th percentile), overweight (85th-95th percentile), and obese (>95th percentile). <b>Results</b>: Among 243 patients (mean age 10.4 years, 53% male), 4 (1.6%) were malnourished, 192 (79%) had normal weight, and 47 (19.3%) were overweight (OW)/obese (26 (10.7%) OW, and 21 (8.6%) were obese). OW/obese patients (mean age 11.3 years, 61.7% male) included 20 patients (42.5%) with two severe CF-related mutations, 21 (44%) with pancreatic insufficiency, and 40 (85.1%) receiving CFTR modulator treatment. Obstructive sleep apnea (OSA) was the most common comorbidity in OW/obese patients with CF, followed by impaired glucose intolerance and CF-related diabetes and hyperlipidemia; these associations did not reach statistical significance. <b>Conclusions</b>: Overweight/obesity affects nearly one in five patients with CF, including those with severe genotype and pancreatic insufficiency.