Sleep Initiation and Maintenance Disorders: Tworoger SS

Tworoger SS, Yasui Y, Vitiello MV, Schwartz RS, Ulrich CM, Aiello EJ, Irwin ML, Bowen D, Potter JD, McTiernan A. · The Fred Hutchinson Cancer Research Center, Division of Public Health Sciences, Cancer Prevention Research Program, Seattle, Wash 98109-1024, USA. · Sleep. · Pubmed #14655916 No free full text.

Abstract: STUDY OBJECTIVES: To examine the effects of a moderate-intensity exercise or stretching intervention and changes in fitness, body mass index, or time spent outdoors on self-reported sleep quality and to examine the relationship between the amount and timing of exercise and sleep quality. DESIGN: A randomized intervention trial. SETTING: A cancer research center in Seattle, Washington. PARTICIPANTS: Postmenopausal, overweight or obese, sedentary women not taking hormone replacement therapy, aged 50 to 75 years, and recruited from the Seattle metropolitan area. INTERVENTIONS: A yearlong moderate-intensity exercise (n=87) and a low-intensity stretching (n=86) program. MEASUREMENTS AND RESULTS: Among morning exercisers, those who exercised at least 225 minutes per week had less trouble falling asleep (odds ratio [OR]: 0.3, P < or = .05) compared with those who exercised less than 180 minutes per week. However, among evening exercisers, those who exercised at least 225 minutes per week had more trouble falling asleep (OR: 3.3, P < or = .05) compared to those who exercised less than 180 minutes per week. Stretchers were less likely to use sleep medication (OR = 0.4, P < or = .05) and have trouble falling asleep (OR: 0.7, P < or = .10) during the intervention period compared with baseline. A greater than 10% versus a 1% or less increase in maximum O2 consumption over the year was associated with longer sleep duration (P < or = .05), less frequently falling asleep during quiet activities (P < or = .05), and less use of sleep medication (P < or = .05). Reductions in body mass index and increases in time spent outdoors had inconsistent effects on sleep quality. CONCLUSIONS: Both stretching and exercise interventions may improve sleep quality in sedentary, overweight, postmenopausal women. Increased fitness was associated with improvements in sleep. However, the effect of moderate-intensity exercise may depend on the amount of exercise and time of day it is performed.

Tworoger SS, Lee S, Schernhammer ES, Grodstein F. · Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA. · Alzheimer Dis Assoc Disord. · Pubmed #16493235 No free full text.

Abstract: We examined the association of sleep duration, snoring, and difficulty sleeping with cognitive function in a cohort of community-dwelling women. Women (n = 1844), aged 70 to 81 years at initial cognitive interview in 2000, are members of the Nurses' Health Study cohort. Women completed six tests of cognitive function encompassing general cognition, verbal memory, category fluency, and attention. We repeated the assessment 2 years later. We used linear regression models to obtain multivariate-adjusted mean differences in initial test performance, and in cognitive decline over time, across categories of sleep duration (< or =5,6,7,8,9+ hours/night), frequency of snoring (never, occasionally, regularly), and sleep difficulties (rarely/never, occasionally, regularly). In analyses of initial test performance, women sleeping < or =5 hours/night scored worse than women sleeping 7 hours/night (mean difference on global score combining all cognitive tests = 0.15 standard units, 95% CI: -0.28, -0.02). Women who regularly had difficulty falling or staying asleep scored 0.11 units lower on the global score (95% CI: -0.22, 0.01) compared with those who rarely had difficulty sleeping. These differences were equivalent to the mean differences in score observed between participants who were 4 to 5 years apart in age. We found no associations with snoring or with any of the sleep variables and cognitive decline over 2 years. Associations between sleep patterns and initial cognitive function may be clinically relevant given that diminished cognition is a risk factor for dementia. However, the lack of an association with prospective cognitive decline warrants further investigation.