The article "Association of Sleep-Disordered Breathing, Sleep Apnea, and Hypertension in a Large Community-Based Study" published in the Journal of the American Medical Association in April 2000 is the largest published population-based study to provide the breakdown of subjects’ apnea-hypopnea index (AHI) by body-mass index (BMI). Sleep apnea, as defined by the National Institutes of Health Sleep Heart Health Study, is an AHI of five or greater. An AHI ³
5 has been shown to have significant consequences and should be treated. According to Nieto et al, the majority of subjects with an AHI ³
5 are not obese.
While obesity is clearly a risk factor for sleep apnea, sleep apnea is multi-factorial and occurs among people in all weight categories. It should be noted that the relationship between BMI and OSA is weaker among the elderly and children.
As the AHI increases, the proportion of subjects with OSA who are obese does increase:
Thus in screening for sleep apnea, it is important to consider all risk factors and presenting symptoms. Risk factors include a family history of sleep apnea, a large neck, a recessed chin, male sex, abnormalities in the structure of the upper airway, smoking, alcohol use, and age, as well as excess weight.
Presenting symptoms include loud snoring, excessive daytime sleepiness (i.e., falling asleep easily and sometimes inappropriately), high blood pressure and other cardiovascular complications, morning headaches, memory problems, feelings of depression, reflux, nocturia, and impotence. The vast majority of the more than twelve million Americans with sleep apnea have not been diagnosed.
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