Elevated incidence of sleep apnea in acromegaly – correlation to disease activity

Grunstein et al. [1] found an elevated prevalence of sleep apnea in patients with acromegaly. We performed polysomnographies in 52 patients with acromegaly on two consecutive nights. Patients were considered of having sleep apnea if they had more than 10 apneas or hypopneas per hour (respiratory disturbance index (RDI) >10/h). If these apneas were predominantly obstructive, they were considered as patients with obstructive sleep apnea (OSA), otherwise with central sleep apnea (CSA). The cohort consisted of 25 male and 27 female patients with a median age of 51 years (range 19–82). 44 patients underwent transsphenoidal surgery, 9 had received conventional radiation therapy afterwards. 16 patients had been currently treated with somatostatin analogues and 2 with dopamine agonists. 21 patients had “safe“ growth hormone levels (<2,5) and normalised IGF-1 levels. 31 had active acromegaly; 9 without prior medical treatment. 29 patients (56%) were found to have a RDI of >10/hr and 12 of them had a RDI >20/hr. Four of these 29 patients (13%) had a CSA with a RDI >10/hr, 24 had predominantly OSA. A correlation was found between the duration of the active disease and the RDI (r=0,29; n=52; p<0,05). As expected there was also a positive correlation between RDI and BMI (r=0,294; n=52; p<0,05). We could also find a correlation between disease activity and RDI (r=0,351; n=52; p<0,05). 20/31 patients with biochemical active acromegaly had SA, compared to 9/21 patients in the cured group.

56% of our patients had a sleep apnea. After cure the incidence declined significantly. Due to the frequent occurrence of respiratory disturbances and their positive correlation to the duration of acromegaly, we believe that polysomnographies should be performed in patients with long-term (>10 years) active acromegaly and increased BMI.

[1] Grunstein RR et al. (1991)