Low-carb, High-fat Diet Seen to Safely Treat PH With Metabolic Syndrome

A ketogenic diet — one that’s low in carbohydrates and higher in fat  — given under medical supervision seems to be safe and effective in treating pulmonary hypertension (PH) when it is associated metabolic syndrome, a case report suggests.

The report, “Nutritional ketosis to treat pulmonary hypertension associated with obesity and metabolic syndrome: a case report,” was published in the journal Pulmonary Circulation.

Metabolic syndrome refers to a group of conditions that include high blood pressure and blood sugar levels, excess fat around the waist, high levels of triglycerides (a type of fat, measured in the blood), and low levels of HDL, the so-called “good cholesterol.” Obesity and type 2 diabetes are risk factors for this syndrome.

Particularly, metabolic syndrome is highly prevalent among people with PH who have heart failure with preserved ejection fraction, which means the heart pumps normally but is too stiff to fill properly. This raises the possibility that metabolic syndrome may contribute to PH.

A specific nutritional intervention, called the ketogenic diet, has been found to be safe and effective in lowering inflammation, insulin use, and weight in people with type 2 diabetes.

Ketogenic (or keto) diet involves a significant reduction in carbohydrate intake, replacing carbs with fat and, at a more moderate level, proteins. The drop in carbs induces a metabolic state called ketosis, in which ketone bodies become a source of cellular energy instead of carbs (breads, pastas, processed cereals, etc.). As a result, blood sugar and weight tend to drop.

A previous study showed an improvement in hemodynamics, or blood flow parameters, as well as lower blood cholesterol after gastric bypass surgery to lose weight in a woman with obesity and pulmonary arterial hypertension.

Considering the role of ketogenic diet and weight loss on improving metabolic conditions related with PH, the researchers proposed that a keto diet may lead to clinical and hemodynamic improvements in PH patients who have metabolic syndrome.

A team led by researchers at National Jewish Health in Denver described the case of a woman, 62, a former smoker who arrived at their center morbidly obese, and with a one-year history of shortness of breath and low blood oxygen levels. Despite using supplemental oxygen, she continued to experience shortness of breath and fatigue. The woman lived at nearly 7,100 feet (about 2,165 meters) above sea level.

Spirometry measures, including forced expiratory volume in one second (FEV1%), forced vital capacity (FVC) and the FEV1/FVC ratio, were determined to assess lung function. Both FEV1 and FVC are measures of how much air a person can exhale after a forced breath.

Hemodynamic parameters, such as mean pulmonary arterial pressure (mPAP), pulmonary artery occlusion pressure (PAOP), cardiac output, and pulmonary vascular resistance (PVR) were also studied. PAOP is a measure of left heart filling pressure, cardiac output refers to the amount of blood pumped through the circulatory system, and PVR evaluates the internal resistance to blood flow within the pulmonary arteries.

Cardiac function was measured through New York Heart Association (NYHA) Classification.

Due to her various co-existing illnesses —  metabolic syndrome, obesity, fatty liver disease, and PH — she was classified as group 3 PH (PH related to lung disease) and advised to adopt drastic lifestyle changes to arrest and reverse metabolic syndrome.

The patient was prescribed atorvastatin, a medicine to reduce blood cholesterol levels, and started on a ketogenic diet. Her progress on this diet was followed virtually, using through a constant care platform provided by a telehealth team.

The platform allows patients to receive education and practical resources, while also being able to connect with other patients for social support.

Daily glucose, ketone, weight, blood pressure, and symptoms were recorded, and the care plan was regularly adjusted according to her needs and goals.

Over one year, the patient lost 34 kg (about 75 lbs; 25% body weight reduction), her body mass index — a measure of body fat — dropped from 45.5 kg/m² to 34.1 kg/m², while her triglycerides fell from 256 mg/dL to 194 mg/dL.

Significant improvements in FEV1 (63% to 84%) and FVC (65% to 88%) were also observed, as were in hemodynamics measures.

The patient’s NYHA functional class improved from 3 to 2, reflecting fewer limitations. She reported now able to walk her dog one mile near her home without needing supplemental oxygen.

Overall, these results showed that addressing metabolic syndrome via a supervised ketogenic diet may have a key role in treating PH.

“In patients with Group 2 or 3 PH, it is paramount to treat the underlying condition,” the researchers wrote.

“We bring this case and technique to the pulmonary hypertension community to share a tool in our therapeutic toolkit and highlight the importance of nutritional advice extending beyond telling a patient they should lose weight to invoking a rational strategy,” they added.