Sleep, blood pressure and obesity in 22,389 New Zealanders

To determine the relationship of sleep disorders with blood pressure and obesity in a large, relatively healthy, community-based cohort.

A cross-sectional study was undertaken using data from 22,389 volunteer blood donors in New Zealand aged 16-84 years. Height, weight, neck circumference and blood pressure were measured directly, and data on sleep and other factors were ascertained using a validated self-administered questionnaire.

Even in a relatively young, non-clinical cohort, lack of sleep (34%), snoring (33%), high blood pressure (20%) and obesity (19%) are common. After adjusting for relevant confounders, participants at high risk of sleep apnoea had double the odds of having high blood pressure but only in participants over 40 years. Very low and high quantities of sleep are also associated with high blood pressure. Even after controlling for neck circumference, self-reported sleep apnoea, sleep dissatisfaction and low amounts of sleep are associated with a higher body mass index.

Obesity and hypertension have significant associations with a variety of sleep disorders, even in those less than 40 years of age and after adjusting for a wide range of potential confounders.