A 62-year-old morbidly obese woman from Salida, Colorado (elevation 7,093 feet), with past tobacco use presented with one year of fatigue, dyspnea, and unexplained hypoxemia. She was previously diagnosed with obstructive sleep apnea, treated with CPAP and supplemental oxygen, but symptoms persisted with minimal walking. She required 2 L of oxygen at rest and 5-8 L with ambulation at her home elevation.
Vital signs were significant for BMI 45.4 kg/m2 and oxygen saturation 93% on 3 L. Physiology and imaging tests showed no significant underlying lung disease.
Echocardiogram showed increased right ventricular systolic pressure at 54 mmHg (previously normal), mild right atrial enlargement, and elevated mean left atrial pressure. Hemodynamics revealed mild pre-capillary pulmonary hypertension (PH): mean right atrial pressure 12 mmHg, mean pulmonary artery pressure (mPAP) 33 mmHg, mean pulmonary artery occlusion pressure (PAOP) 14 mmHg, direct Fick cardiac output (CO) 6.26 L/min, and pulmonary vascular resistance (PVR) 3.04 Wood units.
Given her morbid obesity, metabolic syndrome (HbA1c 6.2%, triglycerides 256 mg/dL, HDLc 41 mg/dL), fatty liver disease, and high-normal PAOP, we classified her as having combined WHO Group 2 and 3 PH, and counseled aggressive lifestyle changes.
The patient initiated a medically-supervised ketogenic diet. She lost 34 kg in one year, achieved a BMI < 40 kg/m2, normalized her triglycerides, and eliminated her supplemental oxygen requirement. Her NYHA functional class improved from III to II, and repeat hemodynamics after one year of ketogenic diet showed improvement, with mPAP 28 mmHg, mean PAOP 12 mmHg, CO 6.0 L/min, and PVR 2.7 Wood units. She now walks her dog one mile at home elevation without supplemental oxygen. This case highlights the success and feasibility of a dietary approach to treat pulmonary hypertension associated with metabolic syndrome with improvement in clinical status and hemodynamics.