Interrelationships between diet quality and health-related quality of life in Irish adults living with cystic fibrosis

Purpose: In the Cystic Fibrosis (CF) modulator era, focus for many has shifted from growth and survival to prevention of diet-related chronic diseases. In doing so, diet quality should be prioritised. However, factors influencing diet quality in CF have yet to be examined. This study aims to explore relationships between health-related quality of life (HRQoL), demographic and clinical characteristics, and diet quality in adults living with CF. Methods: Cross-sectional study of Irish adults with CF. Dietary intake was assessed using three-day food diaries and analysed using the Healthy Eating Index-2020 (HEI-2020) and Diet Quality Index-International (DQI-I), both scored 0–100, with higher scores indicating better diet quality. Patient-reported outcome measure questionnaires collected HRQoL data and symptom status. Data was statistically analysed in SPSS®. Results: Among N = 73 participants (female: 56.2%, age: 35.1 ± 10.3 years), 79.4% were taking CFTR modulators. Mean predicted percentage forced expiratory volume (FEV₁%) was 78.7 ± 24.9%, and median body mass index was 23.9 (4.2) kg/m². Mean HEI-2020 and DQI-I scores were 59.3 ± 12.4 and 51.2 ± 9.8, respectively. Anxiety/depression symptoms were reported by 43.1% of participants, and 30.6% reported the presence of pain/discomfort. Bloating in stomach was reported in 68.1% of participants, with 43.1% reporting moderate to severe symptoms. FEV₁% and digestive symptoms were independently positive significant predictors of HEI-2020 scores (R²adj = 0.166, n = 67, p = 0.004). Conclusion: In the modulator era, suboptimal vitality, anxiety / depression, and gut symptoms remain prevalent among adults living with CF. Future dietary interventions should aim to improve diet quality and consider incorporating dietary patterns that positively influence the gut microbiome.