They're not sure if the flashes cause the insomnia, or it's the lack of sleep that causes the flashes, but either way there seems to be more of an association between the two than with the menopause.
The researchers interviewed 3,243 women in California whose ages ranged from 35 to 65 years. The vast majority - nearly 60 per cent - hadn't reached menopause, just 22 per cent were going through the menopause, and the rest were postmenopausal.
Chronic insomnia - defined as poor or non-restorative sleep over a six-month period - was experienced by 80 per cent of all women who also suffered hot flashes.
(Source: Archives of Internal Medicine, 2006; 166: 1262-7).
E-news broadcast 17 August 2006 No.284 [Subscribe]