NOCTURNAL BREATHING ABNORMALITIES IN ACROMEGALY AFTER ADENOMECTOMY

OBJECTIVE The incidence of sleep apnoea is increased in acromegaly. Th e aim of the study was to determine the occurrence of nocturnal breath ing abnormalities and upper airway morphology in acromegalic patients some years after adenomectomy. DESIGN A case-control study. PATIENTS E leven patients with treated acromegaly and two control groups: (1) sle ep studies: 197 subjects randomly selected from the population, (2) ce phalometry: 27 healthy subjects and 17 patients with obstructive sleep apnoea. MEASUREMENTS Nocturnal breathing was monitored with a static charge-sensitive bed. The upper airway soft tissues and bone morpholog y were assessed by cephalometric X-ray photography, The upper airway c ollapsibility was investigated with dynamic nasopharyngoscopy, Endocri nological investigations were also performed. RESULTS Nocturnal breath ing abnormalities were present in all but one acromegalic patient (91% ), which was far more frequent than in the general population (29.4%, P < 0.0001). Treated acromegaly was the most powerful predictor of bre athing abnormalities, independent of the other significant predictors, age and body mass index, The predominant breathing abnormality was pe riodic breathing with symmetrically waxing and waning respiratory effo rt without a major body movement component, Episodes of complete obstr uction with repetitive arousals were rare. Except for the longer soft palate, the cephalometric findings were similar to normal. In comparis on to obstructive sleep apnoea, the treated acromegalic patients had r ather prognathic endoscopy collapsible upper airways at the level of t he soft palate, whereas at the base of the tongue little, if any, dyna mic narrowing was observed. CONCLUSION our study confirms that nocturn al breathing abnormalities are common in treated acromegaly, and may p ersist years after the removal of the GH secreting tumour. The breathi ng abnormalities and the upper airway morphology in acromegalic patien ts after adenomectomy are different from those observed in primary obs tructive sleep apnoea, suggesting a different pathophysiology of the a irway obstruction.