Sleep apnea in acromegaly: pathogenetic factors and long-term follow up
C. Castellani, G. Francia, M. Ferrari, E. Viva & M. Davì
Background: Sleep apnea syndrome (SAS) is a common disease in acromegaly and it can persist during remission in up to 58% of the patients. Data regarding long term outcome of SAS in acromegalic patients are lacking. Moreover it is still unknown which component, either craniofacial deformation or soft tissue hypertrophy of the palate and upper airways, may play the major role in the pathogenesis of this complication.
Aim: To assess the presence of SAS in a series of acromegalic patients including active and controlled patients and to perform follow up in patients with SAS after biochemical control or during long-term remission. Moreover to evaluate site, degree and possible cause of upper airways obstruction by MRI and fiberoptic nasopharyngoscopy with the Muller maneuver (FNMM).
Patients and method: Polysomnography was performed in 58 acromegalic patients: 33 active and 25 controlled and was repeated in 25 patients with SAS of whom 16 after achieving biochemical control and 9 after long term remission (mean 6.6 years, S.D.±3.2). In 29 patients morphological study of the upper airways by MRI and FNMM was carried out.
Results: The prevalence of SAS was 64% in active and 52% in controlled patients. Among 16 active patients 8 (50%) showed SAS improvement and 2 (12.5%) recovered after biochemical control, whereas in 9 out of 13 (69.2%) controlled patients SAS persisted. Uvula alone or with tongue base was the main site of obstruction assessed by FNMM in 90% of patients. Uvula diameters correlated with the severity of airways narrowing at FNMM and tongue measure with the severity of the AHI.
Conclusions: SAS can improve after biochemical control of acromegaly, but can persist even after long term follow up despite recovery from acromegaly. Hypertrophy of soft palate and tongue is relevant factor responsible for occurrence and severity of SAS.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.