A 48-year-old man has recently been diagnosed with obstructive sleep apnea with an apnea-hypopnea index of 21.2/hr. He presents to the clinic for follow-up because he tried CPAP in the sleep laboratory and felt uncomfortable with it. He asks what the potential risks would be to his health if he chose to forego treatment. What advice do you give him? 

A. Untreated obstructive sleep apnea has an increased risk of mortality due to cardiovascular events including myocardial infarction and stroke. 

B. Untreated obstructive sleep apnea has an increased risk of depression. 

C. Untreated obstructive sleep apnea is associated with a sevenfold increased risk of automobile accidents. 

D. Untreated obstructive sleep apnea raises nocturnal blood pressure, and treatment with CPAP leads to a 2- to 4-mmHg drop in blood pressure. 

E. All of the above is good advice to give to the patient.

The answer is E. (Harrison's 19e Chap. 319) There are numerous benefits to treating OSAHS, and the consequences of untreated OSAHS are numerous and can be severe. They primarily fall in one of three categories: neurocognitive, cardiovascular, and metabolic. The neurocognitive effects are the ones most readily identified by the patient and include daytime sleepiness and inability to concentrate. In addition, individuals with untreated OSAHS have an increased risk of depression, particularly somatic depression with irritability, fatigue, and lack of energy. Moreover, untreated OSAHS increases the risk of occupational accidents by more than twofold and automobile accidents by as much as sevenfold. In addition to the neurocognitive effects, untreated OSA leads to increased sympathetic nervous system activity and increased systemic inflammatory responses. This leads to a loss of the normal nocturnal fall in blood pressure. However, treatment with CPAP can reduce 24-hour ambulatory blood pressure, although the overall effect on blood pressure is modest, decreasing the blood pressure about by 2–4 mmHg. Other cardiovascular and metabolic effects include an increased risk of coronary artery disease, heart failure with and without reduced ejection fraction, atrial and ventricular arrhythmias, atherosclerosis, stroke, and diabetes. Treatment with CPAP yields improvements in insulin resistance, decreases the recurrence rate of atrial fibrillation, and reduces several biomarkers of cardiovascular disease.