Impact of body mass index on the risk assessment of mortality in pulmonary arterial hypertension

Introduction Pulmonary hypertension (PH) is a chronic devastating disease. Obese patients with PH seems to have better outcomes as regards survival, a phenomenon which has been known recently as 'obesity paradox.' Aim of the study To highlight the impact of obesity on the severity of PH via correlating BMI with the different variables of risk stratification for first-year mortality. Patients and methods Eighty five adult pulmonary arterial hypertension patients were enrolled in our study, classified according to their BMI into normal, overweight, and obese groups. They were subjected to clinical assessment, anthropometric measurements, echocardiography, and right heart catheterization. Results The mean age of patients was 38.8 years (+/- 13.57 years), female sex was the predominant. No significant statistical differences were noticed as regards the clinical presentation, hemodynamics as cardiac index, central venous oxygen saturation. Mean of right atrial pressure was lower among overweight patients significantly, 6 min walk distance was higher in overweight group than the other groups. Obese group showed the least percentage of high risk pulmonary arterial hypertension patients among the three groups. Conclusion In spite that obese patients have the lowest exercise tolerance and the highest mean right atrial pressure, yet they have the lowest percentage of high risk patients for mortality, the underlying etiology for this obesity paradox may be not evident however correlation with the fat distribution type is recommended.