On August 11, a communication from Mark Toshner at Papworth Royal Hospital was published in the Annals of the American Thoracic Society titled “Inflammation and Obesity Correlate in Pulmonary Hypertension but Associate with Diverging Outcomes.” This multicenter study systematically reveals for the first time the complex association between C-reactive protein (CRP) and body mass index (BMI) in patients with pulmonary hypertension (PH) and their opposing effects on clinical outcomes.The research team analyzed data from 10,301 PH patients across three major cohorts in the UK and internationally (covering WHO classifications 1-5 of PH). Through time-series clustering, patients were divided into low CRP (median 2 mg/l) and high CRP (median 6.5 mg/l) groups. Patients in the high CRP group exhibited more significant obesity characteristics (median BMI difference of 5.4 kg/m²), higher right atrial pressure (difference of 2 mmHg), and poorer 6-minute walk distance (shortened by 55 meters). Elevated levels of inflammation were significantly associated with reduced survival, increased comorbidities, elevated pulmonary vascular resistance (PVR), and a history of smoking.Notably, although obesity is positively correlated with the inflammatory marker CRP, high BMI exhibited the “obesity paradox”—associated with improved survival, lower PVR, and preserved exercise capacity treatment response. Multi-omics analysis further confirmed that CRP and BMI correspond to different inflammatory molecular profiles: elevated CRP is associated with pro-inflammatory protein expression, while obesity-related inflammation may influence prognosis through metabolic protective mechanisms.The researchers emphasized that this finding has dual implications for PH clinical practice and trial design: CRP can serve as a risk stratification indicator, and obese patients should not be excluded from intensified treatment due to elevated inflammatory markers. The team calls for future research to distinguish the sources of inflammation to develop personalized treatment strategies. This study provides new phenotypic classification criteria for understanding the heterogeneity of PH.