Body Mass Index [BMI] and neck circumference [NC] in diagnosing obstructive sleep apnea

ABSTRACT

Obstructive sleep apnea [OSA] is a common disorder for which obesity is a major risk factor. It has been suggested that the circumference of the neck [NC] is more predictive of OSA than general obesity assessed by the Body Mass Index [BMI]. In the National Tertiary Center for Sleep Study, Hamad Medical Corporation, Qatar, 187 patients were studied to evaluate the usefulness of NC and BMI in diagnosing OSA and in selecting patients for overnight polysomnography [PSG]. Eighty patients [42.8%], 69 males and 11 females with higher mean age, had evidence of significant OSA [RDI>15 events/h sleep]. OSA was found more in the non-Qatari [n=57, 55.3%] than the Qatari's [n=23, 27.4%]. NC mean levels were more in OSA group [42.51 +/- 3.12] than non OSA group [39.57 +/- 4.35] but, classifying obese as BMI = 30, there was no significant difference in the BMI of apneic and non-apneic groups. The study suggested that OSA is more common in males and NC correlates well in predicting OSA compared to generalized obesity/ BMI has no clinical relevance in diagnosing OSA