Ketogenic Diet for Obesity Hypoventilation Syndrome

Inclusion Criteria

• •Obesity (BMI≥30 kg/m2)
• •Hypercapnia (PaCO2\>45 or PvCO2\>50) on blood gas, OR a sleep study with end-tidal/transcutaneous CO2 monitoring showing an awake CO2 level \>50
• •Participants without blood gas data may also have suspected OHS on the basis of serum bicarbonate \>=28 mEq/L
• •Lack of an alternative pulmonary diagnosis that adequately explains hypercapnia. Note that a documented pulmonary diagnosis (e.g. chronic obstructive pulmonary disease (COPD) or asthma) per se will not necessarily exclude subjects, since OHS is often misdiagnosed as obstructive lung disease. Functional or radiographic data must corroborate the presence of the alternate diagnosis.
• •Subjects must have had a sleep study and clinical evaluation for sleep apnea. Most subjects with OHS are expected to have concomitant obstructive sleep apnea (OSA). This information is necessary to determine whether continuous positive airway pressure (CPAP)/noninvasive ventilation (NIV) will be used on the research sleep studies.