Obesity in Pulmonary Arterial Hypertension. The Pulmonary Hypertension Association Registry

Abstract

Rationale: Obesity is associated with pulmonary arterial hypertension (PAH), but its impact on outcomes such as health-related quality of life (HRQoL), hospitalizations, and survival is not well understood.Objectives: To assess the effect of obesity on HRQoL, hospitalizations, and survival in patients with PAH.Methods: We performed a cohort study of adults with PAH from the Pulmonary Hypertension Association Registry, a prospective multicenter registry. Multivariate linear mixed-effects regression was used to examine the relationship between weight categories and HRQoL using the Short Form-12 and emPHasis-10. We used multivariable negative binomial regression to estimate hospitalization incidence rate ratios (IRRs) and Cox regression to estimate hazard ratios (HRs) for transplant-free survival by weight status.Results: A total of 767 subjects were included (mean age of 57 years, 74% female, 33% overweight, and 40% with obesity), with median follow-up duration of 527 days. Overweight patients and patients with obesity had higher baseline emPHasis-10 scores (worse HRQoL), which persisted over time (P < 0.001). Patients who are overweight and obese have a trend toward increased incidence of hospitalizations compared with normal-weight patients (IRR, 1.34; 95% confidence interval [95% CI], 0.94-1.92 and IRR, 1.33; 95% CI 0.93-1.89, respectively). Overweight patients and patients with obesity had lower risk of transplant or death compared with normal-weight patients (HR, 0.45; 95% CI, 0.25-0.80 and HR, 0.39; 95% CI, 0.22-0.70, respectively).Conclusions: In a large multicenter, prospective cohort of PAH, patients who were overweight or obese had worse disease-specific HRQoL despite better transplant-free survival compared with normal-weight patients. Future interventions should address the specific needs of these patients.

Keywords: hospitalization; obesity; pulmonary arterial hypertension; quality of life; survival analysis.

Figure 1.

Flowchart of study inclusion. BMI = body mass index; CTEPH = chronic thromboembolic pulmonary hypertension; PAH = pulmonary arterial hypertension; PPHN = persistent pulmonary hypertension of the newborn; PVOD = pulmonary veno-occlusive disease.

Figure 2.

Health-related quality of life scores (HRQoL) by weight categories. Mean HRQoL measures and 95% confidence intervals for different weight categories. β coefficients are reported from multivariable mixed-effects generalized linear regression models. (A) emPHasis-10 scores (high score = worse HRQoL). (B) Short Form-12 physical scores (higher score = better HRQoL). (C) Short Form-12 mental scores (higher score = better HRQoL). SE = standard error; SF-12 = Short Form-12.

Figure 3.

Interaction plot showing age as an effect modifier between body mass index and emPHasis-10 score, with sample density shown along the x-axis.

Figure 4.

Transplant-free survival by weight status. Kaplan-Meier plot of transplant-free survival for weight categories from time of Pulmonary Hypertension Association Registry enrollment over a 2-year follow-up period.