Flinders University: Link between irregular sleep and hypertension risk

A study of more than two million nights of sleep and blood pressure data found that irregularities in sleep timing and duration were associated with an increased risk of hypertension.

Results show that high sleep duration irregularity was associated with a 9% to 15% increase in hypertension risk. Furthermore, a 38-minute increase in sleep midpoint irregularity was associated with an 11% risk increase, and a 31-minute increase in sleep onset time irregularity was associated with a 29% increased risk of hypertension.

“This new approach to non-invasive nightly monitoring of sleep duration and timing in people’s homes for an average period of six months each combined with regular blood pressure monitoring has shown us just how important having a regular sleep routine and getting enough sleep is for your health, in this case your heart health,” said lead author Dr Hannah Scott from the Adelaide Institute for Sleep Health (AISH) at Flinders University.

“These novel data shed new light into the restorative benefits of sleep and raise potential concerns for the substantial proportion of shift workers in our modern 24-hour society.”

The researchers analysed data collected over nine months from 12,300 participants who were between 18 and 90 years old. Metrics were recorded with an under-mattress sleep device and a portable blood pressure monitor. Sleep duration regularity was assessed as the standard deviation via device-assessed total sleep time. Sleep timing regularity was assessed as the standard deviation in sleep onset time and in sleep midpoint. Logistic regressions controlling for age, sex, body mass index, and mean total sleep time were conducted to investigate potential associations between sleep regularity and hypertension, which was found in 2,499 participants.

“These new insights into the potential adverse impact of irregular sleep timing and duration on heart health further highlight the importance of the role synchronizing the body clock and prioritizing enough sleep opportunity for optimal health and wellbeing,” said senior author Professor Danny Eckert, Director of AISH.

The researchers noted that prior studies of sleep and heart health have been limited in sample size and restricted to a short period of time. The current study investigated associations between sleep regularity and hypertension in a large, global sample over multiple months.

This was an unfunded investigator-initiated study. Deidentified data were provided by Withings for unrestricted investigator-led analysis. One of the co-authors serves as a consultant for Withings.