Currently, over 32% of US adults are obese. McQuillan (Circulation 2001) found a correlation between obesity and pulmonary artery systolic pressure. We hypothesized that patients with World Health Organization (WHO) diagnostic group I pulmonary arterial hypertension (PAH) may have a larger body mass index (BMI) compared to age and sex matched controls in the National Health and Nutrition Examination Survey (NHANES).
All patients enrolled in REVEAL were eligible. Data analyzed included BMI, age, and sex at the time of PAH diagnosis by right heart catheterization (RHC). The results were compared to an age and sex matched group from the NHANES. Specifically, differences in BMI, percentage obese (BMI ≥ 30) and percentage underweight (BMI < 18.5) in the entire PAH group and subgroups of idiopathic and associated PAH patients were determined.
2,141 REVEAL patients with available height and weight data were analyzed: age 48 ± 17, 1681 (78.5%) women. Mean BMI compared at time of PAH diagnosis by RHC was no different for the entire group of PAH patients (Overall in table) compared to NHANES (see table); however, both the percentage obese and underweight were increased in the PAH patients. Subgroup analysis demonstrated that the idiopathic PAH and PAH associated with drugs and toxins had both higher BMI and percentage obese, whereas three subgroups (congenital heart disease, connective tissue disease and HIV) had lower mean BMI.
The mean BMI in the REVEAL (WHO group I PAH) patients was the same as the normal comparison group; however, the percentages of obese and underweight patients were increased in patients compared to the NHANES population. The discrepancy can be explained by the balancing effect of more overweight and underweight patients in different WHO PAH subgroups. The reason for the increased frequency of obesity in IPAH is unknown and will require additional analysis.
Body habitus varies with underlying etiology of PAH (eg, CTD and CHD subgroups being relatively underweight while IPAH and Drugs/toxins are overweight).
Charles Burger, No Financial Disclosure Information; No Product/Research Disclosure Information