New research has found that people who don’t get enough sleep, get too much sleep, or who have poor quality sleep have increased levels of calcium in their coronary arteries – an early indicator of cardiovascular disease. Dr Chan-Won Kim of Kangbuk Samsung Hospital of Sungkyunkwan University School of Medicine in Seoul (South Korea), and colleagues anazlyed data from a sleep questionnaire completed by more than 47,000 men and women, with an average age of 42. Results showed that the participants’ average sleep duration was 6.4 hours per night, and about 84% reported their sleep quality as “good.” Short sleepers – those who got 5 hours or less sleep per night – were found to have 50% more calcium in their coronary arteries than those who slept for 7 hours per night, while long sleepers – those who slept for 9 hours or more – had 70% more calcium than those who slept for 7 hours. Participants who reported poor sleep quality also tended to have more coronary calcium and their arteries tended to be stiffer. While the study does not prove that sleep problems are the cause of early cardiovascular disease, it does suggest that sleep problems may be an indicator of health problems. “The associations of too short or too long sleep duration and of poor sleep quality with early indicators of heart disease, such as coronary calcium and arterial stiffness, provides strong support to the increasing body of evidence that links inadequate sleep with an increased risk of heart attacks,” said Dr Kim. “It is still not clear if inadequate sleep is the cause or the consequence of ill health, but good sleep hygiene, including avoiding electronic media at bedtime, should be part of a healthy lifestyle.”