A recent study utilizing Mendelian randomization analyses found that genetically predicted insomnia, short sleep duration, and frequent daytime napping significantly increased the risk of various cardiovascular diseases, including coronary artery disease, myocardial infarction, heart failure, atrial fibrillation, and stroke. The effects of insomnia and short sleep on cardiovascular diseases were partially mediated by major depressive disorder, and being a morning person was linked to a decreased risk of major depressive disorder.

Source: Open Heart