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Wake up time, light, and mood in a population sample age 40-64 years.

Endo T, Kripke DF, Ancoli-Israel S - Psychiatry Investig (2014)

Bottom Line: From 1990 to 1994, a home survey of sleep disorders among adults ages 40-64 was conducted in the City of San Diego California, using stratified representative sampling techniques.Questionnaires included the CESD depression scale and a scale of symptoms typical of winter depression.Complete data were available from 286 men and women, whose mean in-bed intervals averaged 7 hours and 42 minutes.

View Article: PubMed Central - PubMed

Affiliation: Sleep Clinic Chofu, Tokyo, Japan.

ABSTRACT

Objective: Concern that disturbances of sleep and light exposures at night might increase cancer risks have been expressed, but little actual exposure data has been collected. Measurements from a representative population sample were examined to understand the magnitude of in-bed light exposure at night and possible correlates.

Methods: From 1990 to 1994, a home survey of sleep disorders among adults ages 40-64 was conducted in the City of San Diego California, using stratified representative sampling techniques. Along with questionnaires, sleep logs, and 3-night wrist activity and pulse oximetry measures, bedside illumination was measured with a computer recording system. Questionnaires included the CESD depression scale and a scale of symptoms typical of winter depression.

Results: Complete data were available from 286 men and women, whose mean in-bed intervals averaged 7 hours and 42 minutes. The mean room illumination during the first part of the night was mean 12.7 lux (median 3.2 lux) and during the last 2 hours in bed averaged 28.7 lux (median 18.9 lux). Nocturnal light exposure was positively correlated with age, male gender, summer season, time in bed, wake-up time, and depressive symptoms.

Conclusion: Complex bi-directional interactions may take place between sleep disturbances, depression, time in bed, wake-up-time, and in-bed illumination. The most crucial light exposures appear to occur in the last 2 hours in bed, largely after dawn, so daylight exposure may be an important factor.

No MeSH data available.


Related in: MedlinePlus

Time of going to bed (open circles) and time of getting out of bed (black circles) versus the illumination in the late in-bed interval. The illumination scale is semi-logarithmic. For convenience of display versus clock time, the times of going to bed are shown above times of awakening in the morning. The positive correlations of late-in-bed illumination with times of retiring and arising are shown. LIBP: late in-bed period.
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Figure 2: Time of going to bed (open circles) and time of getting out of bed (black circles) versus the illumination in the late in-bed interval. The illumination scale is semi-logarithmic. For convenience of display versus clock time, the times of going to bed are shown above times of awakening in the morning. The positive correlations of late-in-bed illumination with times of retiring and arising are shown. LIBP: late in-bed period.

Mentions: Figure 2 illustrates the relationship between the room illumination during LIBP and the in-bed timing. The log-transformed room illumination during LIBP was positively correlated with the times going to bed (r=0.32) and getting out of bed (r=0.58) and with in-bed interval length (rp=0.33, partial correlation controlled for gender, age and day length, p<0.0001), but the illumination of EIBP was not correlated to in-bed timing. The log-transformed room illumination during LIBP was also positively correlated with subjectively reported wake up time (partial correlation controlled for gender, age and day length, r=0.42, p<0.0001). The log-transformed room illumination during LIBP was significantly related to age, but this effect lost significance when the time getting out of bed was added as a covariate.


Wake up time, light, and mood in a population sample age 40-64 years.

Endo T, Kripke DF, Ancoli-Israel S - Psychiatry Investig (2014)

Time of going to bed (open circles) and time of getting out of bed (black circles) versus the illumination in the late in-bed interval. The illumination scale is semi-logarithmic. For convenience of display versus clock time, the times of going to bed are shown above times of awakening in the morning. The positive correlations of late-in-bed illumination with times of retiring and arising are shown. LIBP: late in-bed period.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390587&req=5

Figure 2: Time of going to bed (open circles) and time of getting out of bed (black circles) versus the illumination in the late in-bed interval. The illumination scale is semi-logarithmic. For convenience of display versus clock time, the times of going to bed are shown above times of awakening in the morning. The positive correlations of late-in-bed illumination with times of retiring and arising are shown. LIBP: late in-bed period.
Mentions: Figure 2 illustrates the relationship between the room illumination during LIBP and the in-bed timing. The log-transformed room illumination during LIBP was positively correlated with the times going to bed (r=0.32) and getting out of bed (r=0.58) and with in-bed interval length (rp=0.33, partial correlation controlled for gender, age and day length, p<0.0001), but the illumination of EIBP was not correlated to in-bed timing. The log-transformed room illumination during LIBP was also positively correlated with subjectively reported wake up time (partial correlation controlled for gender, age and day length, r=0.42, p<0.0001). The log-transformed room illumination during LIBP was significantly related to age, but this effect lost significance when the time getting out of bed was added as a covariate.

Bottom Line: From 1990 to 1994, a home survey of sleep disorders among adults ages 40-64 was conducted in the City of San Diego California, using stratified representative sampling techniques.Questionnaires included the CESD depression scale and a scale of symptoms typical of winter depression.Complete data were available from 286 men and women, whose mean in-bed intervals averaged 7 hours and 42 minutes.

View Article: PubMed Central - PubMed

Affiliation: Sleep Clinic Chofu, Tokyo, Japan.

ABSTRACT

Objective: Concern that disturbances of sleep and light exposures at night might increase cancer risks have been expressed, but little actual exposure data has been collected. Measurements from a representative population sample were examined to understand the magnitude of in-bed light exposure at night and possible correlates.

Methods: From 1990 to 1994, a home survey of sleep disorders among adults ages 40-64 was conducted in the City of San Diego California, using stratified representative sampling techniques. Along with questionnaires, sleep logs, and 3-night wrist activity and pulse oximetry measures, bedside illumination was measured with a computer recording system. Questionnaires included the CESD depression scale and a scale of symptoms typical of winter depression.

Results: Complete data were available from 286 men and women, whose mean in-bed intervals averaged 7 hours and 42 minutes. The mean room illumination during the first part of the night was mean 12.7 lux (median 3.2 lux) and during the last 2 hours in bed averaged 28.7 lux (median 18.9 lux). Nocturnal light exposure was positively correlated with age, male gender, summer season, time in bed, wake-up time, and depressive symptoms.

Conclusion: Complex bi-directional interactions may take place between sleep disturbances, depression, time in bed, wake-up-time, and in-bed illumination. The most crucial light exposures appear to occur in the last 2 hours in bed, largely after dawn, so daylight exposure may be an important factor.

No MeSH data available.


Related in: MedlinePlus