Diet and exercise improve cardiac function, QoL in PAH
FROM ATS 2024
SAN DIEGO — A lifestyle intervention focused on diet and exercise can improve cardiac function and the quality of life for patients with pulmonary arterial hypertension (PAH), results of a randomized clinical trial show.
In addition, for those participants in the diet and exercise group who lost weight, right ventricular glucose uptake improved, reported Gustavo A. Heresi, MD, MS of the division of pulmonary medicine at the Cleveland Clinic.
The intervention did not, however, have an effect on insulin sensitivity, suggesting that insulin resistance is not a significant pathological mechanism in PAH, he said in an oral abstract session at the American Thoracic Society’s international conference.
“With these data, in the context of prior studies showing the benefits of exercise interventions, we believe that diet and exercise should be incorporated and thought of as part of the treatment armamentarium for pulmonary arterial hypertension,” he said.
Despite the availability of 14 FDA-approved medications for PAH, the disease is incurable. It is marked by progressive pulmonary vasoconstriction, pulmonary vascular remodeling, fibrosis and inflammation, in situ thrombosis, and right ventricular failure.
Because abnormalities in both glucose and insulin metabolism are prevalent and associated with decreased survival in patients with PAH, Dr. Heresi and colleagues designed a randomized trial to test the hypothesis that a diet and exercise intervention could improve insulin sensitivity and right ventricular function.
PHINE details
In the study, dubbed Pulmonary Arterial Hypertension Improvement with Nutrition and Exercise (PHINE), the investigators enrolled adults with group 1 PAH who were stable on PAH medications for at least 2 months. Patients with portopulmonary hypertension, New York Heart Association (NYHA) class IV heart failure, syncope, or on supplemental oxygen greater than 4 liters per minute were excluded.
The patients were screened with a graded exercise test, intravenous glucose tolerance test, and other measures at baseline, and after stratification by NYHA class and tricuspid annular plane systolic excursion (TAPSE) score were randomized to the intervention arm (16 patients) or standard of care control arm (14 patients).
The intervention consisted of supervised exercise training for 50-60 minutes on a treadmill at 80%-85% of the patient’s maximum heart rate 5 days per week, plus weekly counseling on a combination low glycemic index/Mediterranean dietary pattern. The diet portion included olive oil as the primary fat source, three 1-ounce servings of nuts and peanuts weekly, fish and legumes at a minimum of 3 servings weekly, and no sugar-sweetened beverage, commercial bakery products, pastries, white breads, white rice, or white potatoes.
Results
At the conclusion of the study at 12 weeks there were no statistically significant differences between the groups in either insulin sensitivity or right ventricular strain.
However, patients in the intervention arm had significant improvements compared with controls in mean RV function as measured by TAPSE, improved exercise capacity as measured by peak oxygen uptake and 6-minute walking distance, quality of life as measured by EmPHasis-10 health-related quality of life score, and NYHA functional class.
As noted, right ventricular glucose uptake was improved among those patients in the intervention group who lost weight over the study period.
