Poor sleep is associated with ischaemic heart disease and stroke, according to research presented today at ESC Congress. The observational study in nearly 13 000 people revealed different patterns of sleep disturbance between the two conditions, with ischaemic heart disease being linked to shorter sleep and brief moments of waking up.
“Poor sleep is associated with cardiovascular diseases such as ischaemic heart disease and stroke but the kind of sleep disturbances that are most risky is not well documented,” said lead researcher Dr Nobuo Sasaki, of the Hiroshima Atomic Bomb Casualty Council, Japan. “‘Poor sleep’ includes too short or too long sleep, difficulty falling asleep, and difficulty maintaining sleep.”
This study investigated the association between sleep disturbances and cardiovascular disease. It also aimed to clarify possible differences in sleep disturbances between ischaemic heart disease and stroke.
The study included 12 876 residents of Hiroshima, Japan (6 762 men and 6 114 women, average age 68 years) who were registered for an annual health check. Of those, 773 patients had a history of ischaemic heart disease (myocardial infarction and/or angina), 560 patients had a history of stroke (intracranial haemorrhagic and/or cerebral infarction), and 11 543 had no cardiovascular disease. Patients with both ischaemic heart disease and stroke, or another type of cardiovascular disease, were excluded from the study.
Sleep habits were assessed with the Pittsburgh Sleep Quality Index (PSQI), a 19-item self-reporting questionnaire which yields seven component scores. C1 assesses subjective poor sleep quality, C2 long sleep latency, C3 short sleep duration, C4 low sleep efficiency, C5 difficulty in maintaining sleep, C6 use of sleeping pills, and C7 daytime dysfunction. Each component is ranked 0, 1, 2, or 3, with a score ≥ 2 defining sleep disturbance (except C6 score ≥ 1).