Loneliness in Chronic Obstructive Pulmonary Disease: A Multidimensional Determinant of Clinical Outcomes and Disease Management.

Chronic obstructive pulmonary disease (COPD) imposes a substantial physical and psychosocial burden, yet the role of loneliness remains under-recognised in clinical practice. Loneliness, defined as a subjective discrepancy between desired and actual social relationships, has emerged as a clinically relevant determinant of patient outcomes. This narrative review synthesises current evidence on the epidemiology, mechanisms, and clinical consequences of loneliness in COPD, and evaluates its implications for disease management. Available evidence indicates that loneliness affects a considerable proportion of individuals with COPD, with prevalence estimates ranging from approximately 18% to over 30%, particularly among patients with greater symptom burden, functional limitation, and oxygen dependence. Dyspnoea and advancing disease severity reduce social participation and increase vulnerability to perceived social disconnection. Loneliness influences COPD outcomes through interconnected behavioural, biological, and healthcare engagement pathways, including systemic inflammation, neuroendocrine stress responses, physical inactivity, impaired self-management, and reduced engagement with healthcare services. These mechanisms contribute to poorer clinical trajectories, as loneliness is consistently associated with reduced health-related quality of life, increased exacerbations, higher healthcare utilisation, greater risk of hospitalisation, and elevated mortality, independent of depression and anxiety. Despite this, loneliness is rarely assessed in routine respiratory care, and targeted interventions remain limited. Emerging strategies, including pulmonary rehabilitation, peer support, and digital health interventions, show promise in reducing loneliness and improving outcomes. Loneliness represents a modifiable and clinically actionable risk factor in COPD, and its integration into routine assessment and management may enhance patient engagement, optimise treatment effectiveness, and reduce healthcare burden. Addressing loneliness represents a critical opportunity to advance more effective and comprehensive COPD care.