Insomnia increases blood pressure variability in elderly
medwireNews: Long sleep duration and persistent insomnia are associated with increased visit-to-visit blood pressure (BP) variability in elderly individuals at high risk for cardiovascular disorder, research shows.
The variability in BP in individuals with long sleep duration and insomnia also showed clinical associations with arterial stiffness, suggesting a potentially increased risk for stroke or cardiovascular disease.
Researchers Kazuomi Kario and colleagues, from Jichi Medical University School of Medicine in Tochigi, Japan, suggest that the variability in visit-to-visit BP in these patients "might be derived from an autonomic imbalance and/or baroreceptor dysfunction."
They measured BP variability in 201 elderly individuals, aged an average of 79.9 years, with at least one cardiovascular risk factor during 12 visits over a period of 1 to 3 years.
The average sleep duration was 7.51 hours and the mean carotid artery intima-media thickness (IMT) was 1.03 mm.
Fifty of the participants slept for at least 9 hours per night, and this long sleep duration was significantly associated with visit-to-visit systolic BP variability after adjusting for confounding factors, such as age, diabetes, and smoking habits.
The same association was also significant for the 34 patients with persistent insomnia, whereas there was no association between visit-to-visit systolic BP and a short sleep duration of less than 6 hours per night.
The researchers note in the American Journal of Hypertension that long sleep duration and persistent insomnia each had synergistic interactions with carotid artery stiffness as well as visit-to-visit BP variability.
They found that patients with long sleep durations who were in the highest tertile for carotid artery stiffness had significantly higher BP variability than those with sleep durations of 6 to 9 hours who were in the lowest tertile for carotid artery stiffness.
Patients with insomnia showed significant interactions for both IMT and carotid arterial stiffness.
This suggests that "arterial stiffness could augment the relationship of long sleep duration and persistent insomnia with higher visit-to-visit BP variability," say Kario et al.
They add that the significant relationships seen in their study were independent of hypnotic use.
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By Lucy Piper, Senior medwireNews Reporter