In their provocative article,1 Bursztyn and colleagues demonstrated that elderly individuals who routinely nap in the afternoon have a subsequent overall mortality rate that is doubled. This was evident in those without prior myocardial infarction and persisted when controlling for other risk factors. This study raises important and practical issues that require investigation.
The proposed mechanism for the increase in mortality, particularly vascular mortality, is the increase in sympathetic activity upon awakening that can result in increased heart rate, blood pressure, and platelet aggregability.2,3 However, mortality was not increased in the subgroup of patients with prior myocardial infarction. Was this because the subjects with prior myocardial infarctions were taking β-blockers, which dampen sympathetic activity,4 and/or aspirin, which blocks platelet aggregation?5