The effect of nutritional interventions on intake and quality of life in pulmonary arterial hypertension

This dissertation investigates the role of nutrition in pulmonary arterial hypertension (PAH), a rare and progressive disease characterized by elevated pulmonary artery pressure leading to right heart failure, reduced exercise tolerance, and impaired quality of life (QoL). Despite major pharmacological advances, PAH treatment remains largely symptom-oriented, and nutrition has been an overlooked yet potentially modifiable factor influencing disease progression and well-being.
The central aim of this thesis was to explore how nutritional status, dietary intake, and targeted lifestyle interventions can influence QoL in patients with PAH, and to define the potential of an integrative, patient-centered approach to care.

Summary of Findings
Chapter 2
A narrative review demonstrated that malnutrition is common in PAH, driven by multifactorial causes such as gastrointestinal congestion, inflammation, altered metabolism, and medication side effects. Existing data suggest a high prevalence of deficiencies in iron and vitamin D, yet structured nutritional screening and dietary interventions are rarely implemented in clinical practice.
Chapter 3
The first systematic assessment of nutritional and biochemical status in PAH revealed widespread deficiencies in vitamin D, iron and new found deficiencies of functional vitamin B12, vitamin K1, and suboptimal selenium. Additionally, excessive sugar and fluid intake combined with overly restrictive sodium consumption were observed, likely reflecting the inappropriate application of heart failure (HF) dietary guidelines to PAH. These findings underscore the need for disease-specific nutritional recommendations.
Chapter 4
This pilot intervention introduced a novel video-based e-learning program to improve dietary habits and QoL in PAH patients. Seventeen clinically stable participants completed the program, resulting in sustained significant improvements in dietary patterns and singals of improvement in QoL, particularly in the physical domain, despite high baseline scores and optimal medication treatment. The study demonstrated that personalized digital nutrition education is feasible and can drive meaningful behavioral changes in this population.
Chapter 5
The feasibility of using Fitbit devices to monitor daily physical activity (DPA) was evaluated. While technical limitations affected data completeness, the study revealed that perceived engagement in meaningful activities (gardening, household chores) correlated more strongly with QoL than objective step counts. This finding highlights the importance of subjective measures in lifestyle research.
Chapter 6
A critical narrative review questioned the clinical appropriateness of oral nutritional supplements (ONS) commonly prescribed to patients with malnutrition in HF. Most ONS are ultra-processed, defined by NOVA-classification, and high in sugar, potentially counteracting cardiovascular health goals. The chapter advocates for whole-food, nutrient-rich dietary strategies over industrial formulations, calling for further randomized trials comparing both approaches.
Discussion and Future Perspectives:
This thesis challenges the current paradigm of pharmacologically dominated PAH management by positioning nutrition and QoL as integral components of care. The work proposes:
• Routine assessment and monitoring of nutritional status and QoL.
• Development of PAH-specific dietary guidelines emphasizing protein adequacy, reduced added sugars, and balanced sodium intake.
• Establishment of a PAH Lifestyle Clinic: an integrative care model combining dietetics, physiotherapy, psychosocial support, and digital tools for continuous monitoring.
• Creation of a longitudinal biobank to explore nutritional biomarkers and the microbiome’s role in PAH progression.

Conclusion
This dissertation provides the first comprehensive framework linking nutrition, lifestyle, and QoL in PAH. It demonstrates that nutritional interventions can meaningfully enhance well-being even in optimally treated patients. By integrating nutritional science into PAH management, healthcare can evolve toward a holistic, preventative, and empowering model.