Insomnia and Cardiometabolic Morbidity
Until recently, chronic insomnia has not been linked firmly with significant medical morbidity, such as cardiovascular disease. Several surveys have shown a significant relationship between difficulty falling asleep or poor sleep with cardiometabolic outcomes such as hypertension60-62 and diabetes.63-66 For example, persistent complaints of difficulty initiating or maintaining sleep were associated with an increased risk of hypertension,61 acute myocardial infarction,62 and incident type 2 diabetes.63-66 However, these studies showed relatively small effect sizes and did not include a PSG evaluation so as to control for SDB or other sleep pathology. The findings of these early studies were dismissed as methodologically flawed by many clinicians and researchers alike.67,68 In fact, at least one report showed a reduced mortality rate for those individuals complaining of sleep difficulties after 6 years of follow-up.