Format

Send to

Choose Destination
Sleep. 2011 Nov 1;34(11):1583-93. doi: 10.5665/sleep.1402.

Self-reported sleep duration and time in bed as predictors of physical function decline: results from the InCHIANTI study.

Author information

1
National Institute for Health and Welfare, Department of Health, Functional Capacity and Welfare, Functional Capacity Unit, Turku, Finland. sari.stenholm@thl.fi

Abstract

STUDY OBJECTIVES:

To characterize elderly persons into sleep/rest groups based on their self-reported habitual total sleeping time (TST) and habitual time in bed (TIB) and to examine the prospective association between sleep/rest behavior on physical function decline.

DESIGN:

Population-based InCHIANTI study with 6 years follow-up (Tuscany, Italy).

SETTING:

Community.

PARTICIPANTS:

Men and women aged ≥ 65 years (n = 751).

MEASUREMENTS AND RESULTS:

At baseline, participants were categorized into 5 sleep/rest behavior groups according to their self-reported TST and TIB, computed from bedtime and wake-up time. Physical function was assessed at baseline and at 3- and 6-year follow-ups as walking speed, the Short Physical Performance Battery (SPPB), and self-reported mobility disability (ability to walk 400 m or climb one flight of stairs). Both long (≥ 9 h) TST and long TIB predicted accelerated decline in objectively measured physical performance and greater incidence in subjectively assessed mobility disability, but short (≤ 6 h) TST did not. After combining TST and TIB, long sleepers (TST and TIB ≥ 9 h) experienced the greatest decline in physical performance and had the highest risk for incident mobility disability in comparison to mid-range sleepers with 7-8 h TST and TIB. Subjective short sleepers reporting short (≤ 6 h) TST but long (≥ 9 h) TIB showed a greater decline in SPPB score and had a higher risk of incident mobility disability than true short sleepers with short (≤ 6 h) TST and TIB ≤ 8 hours.

CONCLUSIONS:

Extended time in bed as well as long total sleeping time is associated with greater physical function decline than mid-range or short sleep. TIB offers important additive information to the self-reported sleep duration when evaluating the consequences of sleep duration on health and functional status.

KEYWORDS:

Aging; disability; epidemiology; follow-up studies; gerontology; physical performance; sleep; sleep duration; time in bed

PMID:
22043129
PMCID:
PMC3198213
DOI:
10.5665/sleep.1402
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for PubMed Central
Loading ...
Support Center