Obesity Paradox Uncovered In Pulmonary Hypertension

Jose Caceres, MD, from Jacobi Medical Center/Albert Einstein College of Medicine, recently presented research at the 2014 American Thoracic Society International Conference that adds fuel to the “obesity paradox phenomenon.” Whereas obesity (higher body mass index, or BMI) is usually associated with poorer health outcomes, Dr. Caceres’ research shows obese severe pulmonary hypertension patients actually have a reduced mortality risk.

“In our study of more than a thousand patients with significant pulmonary hypertension, we found that a higher BMI was associated with a reduced mortality risk, even after adjustment for baseline characteristics,” said M. Khalid Mojadid, MD, co-researcher of Dr. Caceres, in a news release. Their retrospective study of 1137 severe pulmonary hypertension patients–361 with a normal BMI, 639 with an obese BMI, and 137 with a morbidly obese BMI–showed that one-year mortality rates were 34.1%, 22.8%, and 12.4%, respectively. However, one-year readmission rates were not significantly different.

“An obesity paradox may also occur in patients with significant pulmonary hypertension,” said lead author Dr. Ronald Zolty.

The researchers were originally concerned about the role obesity plays in the onset of pulmonary hypertension. “Obesity-related illnesses, particularly obesity hypoventilation syndrome and sleep apnea, may play a role in the development of pulmonary hypertension, and so we examined whether the protective effects of obesity seen in patients with heart failure were also seen in these patients,” said Dr. Caceres.

Dr. Zolty has one theory behind the paradox in relation to pulmonary hypertension: “A possible mechanism underlying this phenomenon is increased serum lipoproteins associated with increased body fat, which may play a role in neutralizing circulating toxins and inflammatory proteins.”

The 2014 American Thoracic Society Conference was held in San Diego May 16-21.