Sleep irregularity measurement tied to hypertension, high BP

Hypertension and higher blood pressure (BP) levels are associated with the objective measurement of sleep irregularity, as assessed by standard deviation (SD) of sleep duration for 1 week, particularly in individuals without obstructive sleep apnoea (OSA), a study has shown.

A team of investigators performed a clinical evaluation of adult participants from the ELSA-Brasil study, including objective sleep duration (actigraphy), insomnia, and a sleep study for defining OSA. They used two parameters obtained through actigraphy to quantify sleep irregularity: 7-day SD of sleep duration and 7-day SD of sleep-onset timing.

Independent associations of sleep irregularity with hypertension and BP values were explored through a multivariate analysis.

Of the 1,720 participants (mean age 49 years, 43.4 percent men) analysed, 27 percent had a hypertension diagnosis.

Continuous analysis of 7-day SD of sleep duration showed a modest association with prevalent hypertension, after adjustments for age, gender, race, body mass index, excessive alcohol consumption, physical activity intensity, urinary sodium excretion, insomnia, objective sleep duration, and OSA (apnoea‒hypopnoea index ≥15 events/h).

On the other hand, 7-day SD of sleep duration >90 min independently correlated with systolic (β, 1.55, 95 percent confidence interval [CI], 0.23‒2.8) and diastolic BP (β, 1.07, 95 percent CI, 0.12‒2.01). On stratification analysis that excluded participants with OSA, 7-day SD of sleep duration >90 min correlated with a 48-percent higher likelihood of having hypertension (odds ratio, 1.48, 95 percent CI, 1.05‒2.07).

“No significant associations were observed for the SD of sleep-onset timing,” the investigators said.