Prevalence of pulmonary hypertension and its association with respiratory disturbances in obese patients living at moderately high altitude

To determine the point prevalence of pulmonary hypertension (PH) and its relationship with respiratory disturbances in obese patients living at moderate altitude. A total of 57 obese patients comprised the final sample and consisted of 34 women and 23 men, with a mean age of 42.7+/-12.1 ys and a mean body mass index (BMI) 47.1+/-10.6 kg/m(2) (range from 30.1 to 76.1). The mean living altitude was 2248.7 m, range 2100-2400 m above sea level. Doppler echocardiography, pulmonary function tests, arterial blood gas analysis, and polysomnography were performed. Data showed that 96.5% of the studied sample had daytime PH defined as calculated systolic pulmonary artery pressure (PSAP) >30 mmHg (mean PSAP=50, s.d.=13 mmHg). The severity of diurnal PH was found to be related to the presence of alveolar hypoventilation and BMI. The main risk factor for severity of diurnal PH was hypoventilation with a significant odds ratio (OR) 7.96, 95% CI 1.35-46.84, BMI was (OR 1.12, 95% CI 1.02-1.25) and apnea/hypopnea index was not a predictor of pulmonary hypertension severity (OR 0.99, 95% CI 0.97-1.02). We concluded that prevalence of diurnal PH is high in obese patients living at moderate altitude, and that hypoventilation is the main risk factor associated with the severity of pulmonary hypertension.