Methods and compositions for treating obesity-hypoventilation syndrome
Methods and compositions for treating a subject for obesity-hypoventilation syndrome, or related conditions, are provided. The subject methods include applying an electrical stimulus to a subject in a manner that modulates chest cavity capacity in a manner effective to treat the subject. Also provided are compositions, kits and systems for use in practicing the subject methods.
1. A method of treating a subject for obesity-hypoventilation syndrome (OHS), said method comprising:
providing a subject diagnosed with OHS, wherein the subject has persistence of hypercapnic respiratory failure with a PCO 2 >47 mmHg for at least three months, a body mass index greater than 33, an apnea-hypopnea index (AHI) measured from a complete polysomnographic study of less than 20 events per hour, and a forced expiratory volume/forced vital capacity (FEV 1 /FVC ratio above 0.65; and
treating said subject for OHS by applying an electrical stimulus to:
a diaphragm target site, wherein the stimulus enhances diaphragm contraction during expiration and the stimulus enhances diaphragm relaxation during inspiration; and
a chest wall target site, wherein the stimulus enhances chest cavity capacity during inspiration and reduces chest cavity capacity during expiration.
2. The method according to claim 1 , wherein said method comprises applying the electrical stimulus to said chest wall target site to enhance chest wall contraction.
3. The method according to claim 1 , wherein said electrical stimulus is continuous.
4. The method according to claim 1 , wherein said electrical stimulus is from an implanted intramuscular electrode adjacent to a point of termination of the corresponding motor nerve supply for the muscle at said target site.
5. The method according to claim 1 , wherein said method further comprises synchronizing said electrical stimulus of said at least one target site with said subject's own attempts at breathing.
6. The method according to claim 1 , wherein the electrical stimulation of the diaphragm and chest wall target sites is performed to achieve the maximum possible total lung capacity for said subject.
7. The method according to claim 1 , wherein said electrical stimulus is applied during expiration to inhibit native electrical stimulation of the diaphragm.
8. The method according to claim 1 , wherein said electrical stimulus is applied during expiration to inhibit native electrical stimulation of said subject's chest wall muscles.
9. The method according to claim 1 , wherein dietetic treatment has failed to induce weight loss in said subject for at least 3 months.