SLEEP-APNEA IN ACROMEGALY - PREVALENCE, PATHOGENESIS AND THERAPY - REPORT ON 2 CASES

It has long been known, that irregular, heavy snoring and daytime slee piness are common features of acromegaly. Only recently has the high i ncidence (30-60%) and clinical relevance of the sleep apnoea underlyin g these symptoms been recognized. Both diseases have a group of common symptoms and prognostic features: Increased cardiovascular and respir atory mortality, elevated incidence of hypertension, daytime sleepines s, decreased vitality, headaches and depression. These are very promin ent in sleep apnoea and often reversible under treatment. In acromegal y their etiology has been widely unexplained and they commonly persist even when human growth hormone (hGH) levels remain normal after opera tive treatment. We report on 2 patients presenting with excessive dayt ime sleepiness and severe obstructive sleep apnoea caused by acromegal y. Both had macroglossia and hypertrophy of hypopharyngeal tissues reg ressive after surgical therapy. The average hGH-levels were 20 and 31 ng/ml before and 3 and 1.7 ng/ml several months after operation respec tively. Apnoea indices and minimal oxygen saturations (SO2) were 59/h and 55/h, and 60% and 58% initially and improved postoperatively to 40 /h and 50/h, and 72% and 70%. Polysomnographic parameters were normali zed by NCPAP-therapy pre- and postoperatively and daytime sleepiness i mproved dramatically. In one patient the NCPAP-pressure could be decre ased postoperatively. Since patients with sleep apnoea have an increas ed perioperative risk of hypoxia and because transsphenoidal operation and postoperative nasal tamponade were per formed, both patients were tracheostomised perioperatively. According to the literature sleep ap noea is caused by upper airway obstruction due to swelling of tonge an d hypopharyngeal soft tissues. The question, whether central breathing regulation is also involved remains unsettled. Postoperative tissue s welling is regressive in 60% of the patients and sleep apnoea can impr ove polysomnographialcally and more rarely clinically. In most cases f urther NCPAP-therapy is needed. In conclusion it should be known wheth er sleep apnoea is present or not in acromegalic patients since it is common and has therapeutic consequences for perioperative and long ter m management.