Hot flashes and night sweats in relation to trouble sleeping and daytime sleepiness

The purpose of this study was to determine whether self-reported night sweats (NS) and hot flashes (HF) were differentially associated with sleep problems, assessed by "trouble sleeping" on a symptom checklist and the Sleep Habits Questionnaire (SHQ), or with the degree of daytime fatigue, assessed by "lack of energy" on a symptom checklist and the Epworth Sleepiness Scale (ESS).

Data were drawn from a study of midlife women aged 40-60 in Doha, Qatar (N=841). Participants were categorized as having (1) neither HF nor NS, (2) only HF, (3) only NS, or (4) both HF and NS. Bivariate analyses using χ2 and ANOVA were conducted, followed by logistic and linear regression analyses.

Women with both HF and NS scored significantly higher on the SHQ than those with neither HF nor NS (16.3 vs. 12.6, P<0.001). In contrast, mean ESS did not differ by HF/NS category. Among women with only NS, the odds of reporting trouble sleeping were almost twice as high (adjusted odds ratio [OR]: 1.78, 95% CI: 1.11-2.84), and the odds of reporting lack of energy were more than two times higher (adjusted OR: 2.63, 95% CI: 1.48-4.68), compared with women reporting neither HF nor NS, after controlling for menopausal status, age, depressed mood, aches/stiffness in joints, education, and nationality. Women reporting only HF did not differ significantly from those reporting neither HF nor NS in relation to lack of energy or trouble sleeping.

These findings suggest that NS are more disruptive to women's sleep and daytime fatigue than are HF.