Obese patients with sleep apnea syndrome treated by progesterone

Two obese patients with sleep apnea syndrome were administered chlormadinone acetate (CMA), a synthetic progesterone, known as a potent respiratory stimulant to augment load compensation response as well as CO2 chemosensitivity. Before CMA administration, both cases showed normal chemosensitivity of hypoxic and hypercapnic ventilatory responses (HVR and HCVR) at daytime, although marked oxygen desaturation with sleep apnea was observed. During CMA administration for 7 days, HVR, HCVR and occlusion pressure response to flow-resistive loading were altogether augmented. In one case obstructive sleep apnea (OSA) was altered to obstructive hypopnea, and in the other case central apnea disappeared completely, resulting in remarkable improvement of oxygen desaturation at sleep and daytime somnolence in both cases. We conclude that CMA might be useful in the treatment of sleep apnea syndrome.