According to research published in the Archives of Internal Medicine, sleeping fewer than 7 ½ hours per night could increase the risk of heart disease among the elderly.
In a study of 1,255 Japanese patients with hypertension and an average age of 70.4 years, it was found that short sleep duration was associated with a 1.68-fold increased risk of cardiovascular disease. This was especially true if there was also an observed increase in nighttime blood pressure. In subjects who had both short sleep and high nighttime blood pressure, the risk was increased 4.43-fold.
Lack of sleep has been associated with multiple health problems including obesity, diabetes, and cardiovascular disease.
Eguchi K, et al. "Short sleep duration as an independent predictor of cardiovascular events in Japanese patients with hypertension". Arch Intern Med 2008; 168(20): 2225-30.