Using clinical data to predict sleep hypoxemia in patients with acromegaly

Hypoxemia secondary to sleep apnea is commonly seen in patients with acromegaly, and this alteration apparently leads to considerable morbidity and mortality among such patients. With the objective of identifying hypoxemia based on clinical data, we conducted a cross-sectional study of 34 patients with acromegaly, all of whom were submitted to nocturnal oximetry and evaluation of snoring, as well as to the determination of body mass index (BMI) and neck circumference. In addition, daytime sleepiness was evaluated using the Epworth sleepiness scale (ESS). In this study, sleep hypoxemia was defined as five or more episodes of desaturation per hour. The sensitivity and specificity of the various parameters in predicting such hypoxemia were, respectively, as follows: snoring (92.9% and 35%); BMI>28.5 kg/m2 (71.4% and 60%); neck circumference>44 cm (28.6% and 95%); ESS score>10 (42.9% and 70%). For patients with a neck circumference of more than 44 cm, the probability of sleep hypoxemia was found to increase from 41% (pre-test) to 80% (post-test). For patients with a neck circumference of less than 44 cm, positivity for two or three of the other parameters (snoring, ESS score>10 and BMI>28.5 kg/m2) increased the post-test probability to 62%, whereas positivity for only one (or none) reduced post-test probability to 8%. We can conclude that the clinical parameters evaluated allowed us to predict, with considerable accuracy, whether or not sleep hypoxemia would occur in patients with acromegaly.