Effect of Sandostatin (R) LAR (R) on sleep apnoea in acromegaly: correlation with computerized tomographic cephalometry and hormonal activity

Objectives Sleep apnoea has been reported to occur in subjects with acromeg aly. This study evaluates the relationship among biochemical activity, slee p apnoeic activity and upper airway anatomic profile in acromegaly, and the effect of Sandostatin((R)) LAR((R)), a long-acting somatostatin analogue, on these parameters. Patients Fourteen subjects with acromegaly were recruited. Measurements Subjects were assessed at baseline and those with apnoea-hypop noea index (AHI) greater than or equal to 5 were reassessed after 6 months of treatment with Sandostatin((R)) LAR((R)) 20-30 mg IMI 4-weekly. Biochemi cal activity was assessed with levels of GH and IGF-1. Sleep disordered bre athing was assessed with overnight polysomnography. Upper airway anatomic p rofile was defined with computerized tomographic cephalometry. Results Of 14 subjects (age 42.0 +/- 8.1 years, mean +/- SD; 11 men) at bas eline, there was a positive correlation between GH and tongue length (VT; P = 0.004), and between AHI and cephalometric indices: length of soft palate (PMU; P = 0.002); mandibular plane-hyoid bone distance (MPH; P = 0.017), m aximum thickness of soft palate (Max-SP; P = 0.018) and VT (P = 0.027). Eig ht patients had sleep disordered breathing (AHI greater than or equal to 5) which was predominantly obstructive in nature (AHI = 29.4 +/- 22.6). After treatment, there were significant improvements in hormonal profile: GH, mU /l (before, 51.5 +/- 27.8; after, 8.0 +/- 7.4; P = 0.017) and IGF-1, nmol/l (before, 95.5 +/- 23.4; after, 35.0 +/- 12.4; P = 0.012); sleep-disordered breathing: AHI (before, 29.4 +/- 22.6; after, 13.4 +/- 11.12; P = 0.025), snoring episodes (before, 486 +/- 240; after, 165 +/- 170; P = 0.05); cepha lometric indices, mm: MPH (before, 18.8 +/- 12.1; after, 14.8 +/- 8.4; P = 0.018), VT (before, 72.3 +/- 4.4; after, 69.7 +/- 4.3; P = 0.05). There was a positive correlation between the reduction in GH and AHI (r = 0.738, P = 0.037). Conclusion The findings demonstrated that there was correlation between sle ep apnoea severity and soft tissue overgrowth at the upper airway region in acromegaly. They also suggest that Sandostatin((R)) LAR((R)) improved obst ructive sleep apnoea in acromegaly, and the effect might be partly mediated via a reduction in upper airway soft tissue, in particular that of the ton gue, concomitant with a reduction in GH levels.