Interleukin-6 and Tumor Necrosis Factor-α Are Associated with Quality of Life–Related Symptoms in Pulmonary Arterial Hypertension

Rationale Inflammation is associated with symptoms in many chronic illnesses; however, this link has not been established in pulmonary arterial hypertension. Objectives The objective of this study was to investigate the association between inflammatory markers and quality of life–related symptoms in patients with pulmonary arterial hypertension. We hypothesized that higher circulating IL-6 and tumor necrosis factor-α levels would be associated with worse quality of life–related symptoms. Methods We performed a secondary analysis using baseline and 3-month assessments of 62 subjects in a clinical trial of aspirin and simvastatin to determine the association between plasma IL-6 and tumor necrosis factor-α levels and the Medical Outcomes Study Short Form-36 subscales (pain, vitality, mental health). Measurements and Main Results The mean age was 49.7 ± 13.4 years; 87% were female. Higher IL-6 levels were significantly associated with lower Medical Outcomes Study Short Form-36 subscale scores, indicating worse bodily pain, vitality, and mental health (all P < 0.01). Higher tumor necrosis factor-α levels were significantly associated with increased bodily pain, but better mental health scores. Conclusions IL-6 and tumor necrosis factor-α levels are associated with certain quality of life domains in patients with pulmonary arterial hypertension. Clinical trial registered with www.clinicaltrials.gov (NCT00384865).