Hot flashes often followed by insomnia

NEW YORK, June 29 (Reuters) Women who suffer hot flashes, especially severe hot flashes, often have trouble sleeping, a new study confirms. And, according to study author Maurice M. Ohayon, ''hot flashes are linked with insomnia regardless of the menopausal status of women.'' ''A woman can be in her pre-menopause and have hot flashes during the day and/or the night that may impair sleep quality,'' Ohayon, from the Stanford Sleep Epidemiology Research Center in Palo Alto, California told Reuters Health. As the severity of hot flashes increases, so does the insomnia.

As many as 85 per cent of women going through menopause experience hot flashes, which may last well beyond a woman's last menstrual cycle. Because these unpleasant sensations of intense heat and sweating can occur at night, their presence has been frequently linked to insomnia in menopausal women.

However, because many factors other than hot flashes or menopause can also lead to sleep problems, the exact link between hot flashes and insomnia has been hard to establish.

In Ohayon's study, 982 women were interviewed regarding hot flashes, insomnia and other ailments that might impact sleep.

Of these women, 562 (57.2 per cent) were premenopausal; 219 (22.3 per cent) were perimenopausal, defined as having irregular menstrual bleeding in the previous year; and 201 (20.5 per cent) were postmenopausal, defined as no menstrual bleeding in the previous year.

Information gleaned from these interviews shows that insomnia is ''mostly secondary to hot flashes,'' Ohayon said. ''More importantly, the association between hot flashes and insomnia remains very strong even when we controlled for other factors that could explain insomnia for example, depression, anxiety, sleep apnea, restless legs syndrome'' Ohayon said.

Overall, about 33 per cent of women said they suffered from hot flashes, according to the report published in the Archives of Internal Medicine. This included 12 per cent of premenopausal women, 79 per cent of perimenopausal women, and 39 per cent of postmenopausal women.

About half of the women with hot flashes said these episodes were usually mild and did not involve sweating; about one third said their hot flashes were moderate, meaning the hot flash involved sweating but did not require a woman to stop an activity; and 15 per cent reported severe hot flashes, meaning she experienced sweating and had to stop what she was doing.

More than 80 per cent of women with regular severe hot flashes had chronic insomnia, defined as having trouble falling asleep, staying asleep, ''non-restful'' sleep, or overall dissatisfaction with sleep quality or quantity for at least 6 months.

''Hot flashes remain an important factor in insomnia in women in midlife, independent of their menopausal status,'' Ohayon concluded in his report.

REUTERS SY BST0942