The 2018 study isn’t the only one out there. In fact, there is quite a bit of research that seems to say that sleeping too much is riskier than you think. Per a multi-ethnic cohort study published in 2014 in Preventive Medicine, both short and long sleep durations were linked with all-cause and cardiovascular disease mortality.
Getting more than 10 hours of sleep was associated with metabolic syndrome and elevated triglycerides in both male and female participants in a 2018 study published in BMC Public Health. The same study also found a link between reduced good cholesterol levels, also known as high-density lipoprotein (HDL) cholesterol, increased fasting glucose markers, and increased waist circumference in women who slept for more than 10 hours. Metabolic syndrome refers to a cluster of health conditions that include obesity, high blood pressure, and unhealthy cholesterol levels, and has been linked with premature death in men and women.
It is important to note, however, that while these studies show correlation between early death and oversleeping, it is difficult to establish a definite causation. Researchers are quick to point out that the studies could be reflecting certain underlying health conditions (physical or mental) that could be causing the participants to sleep more. For example, some research has found that depression and low socioeconomic status were common among over-sleepers. Not having a job, financial trouble, and poor nutrition can also cause a person to sleep more.
