Biomedical subjects

Jeffrey A Elliott

Publications and source records attributed to Jeffrey A Elliott.

25 records · Page 2Linked to original sources

PubMed2003

Efficacy of enhanced evening light for advanced sleep phase syndrome.

This study tested whether a newly designed enhanced evening light therapy was well tolerated and effective in relieving symptoms of Advanced, Sleep Phase Syndrome (ASPS). Participants with self-reported ASPS symptoms were 47 older adults (21 men and 26 women, age 60-86). After baseline, participants underwent 28 consecutive days of either dim or enhanced intensity light treatment for 2-3 hr in the evening. Enhanced evening light (approximately 265 lux) exposure was no more effective than a placebo dim light (approximately 2 lux) at alleviating advanced sleep phase as measured by actigraphically recorded sleep and urinary 6-sulphatoxymelatonin (aMT6s) excretion patterns. Participants receiving the enhanced light reported subjective benefit and a significant delay in sleep onset as compared to the placebo. Although compliance was good and the new enhanced evening light therapy design was well tolerated, the benefits were statistically equivocal.

Aged↗

PubMed2002

No association of 6-sulfatoxymelatonin with in-bed 60-Hz magnetic field exposure or illumination level among older adults.

We examined the association of 6-sulfatoxymelatonin (aMT6s) excretion with in-bed 60-Hz magnetic field (MF) exposure and other potential regulators. Adults aged 50-81 years (n=242 years, mean 67.6+/-5.7 years) were monitored for 1 week in their home environments. Mean and maximum MF exposure were assessed with EMDEX Lite instruments. Illumination mesor, amplitude, and acrophase (peak time) were determined from 24-h Actillume wrist monitors. Other regulators of aMT6s assessed were age, usage of melatonin-altering medications, and day length. During two 24-h intervals, all urine voidings were collected. The mesor, amplitude, and acrophase of aMT6s excretion were determined. Multiple regression analyses revealed no association between MF and aMT6s. Medication usage was associated with significantly lower aMT6s mesor and amplitude. Illumination acrophase and amplitude were significantly associated with aMT6s acrophase. These data suggest no influence of nocturnal environmental MF exposure on aMT6s excretion in older adults.

Aged↗

PubMed2002

Depression and endogenous melatonin in postmenopausal women.

BACKGROUND: Previous reports on melatonin secretion in depression are numerous but conflicting. There are very few studies relating the duration of the nocturnal melatonin peak to depression, and the results of those studies have been equivocal. METHODS: We studied mood disorders and urinary melatonin excretion in 382 postmenopausal women. Psychiatric diagnoses and global assessment of functioning (GAF) scores were determined based on a Structured Clinical Interview for DSM-IV Axis I Disorders (SCID). Urinary 6-sulfatoxymelatonin (6-SMT) samples were collected for two 24-h periods at home. RESULTS: A positive family history of depression was significantly related to a longer duration of 6-SMT excretion. There were marginally significant associations between current major depression and delayed offset of 6-SMT excretion and between later acrophase and lifetime major depression, even with control for age, ethnicity, season, and several medications. LIMITATIONS: The subjects were studied in their home environments, where light effects were not controlled. Data were restricted to postmenopausal women, including a limited number of subjects with current major depression. CONCLUSIONS: These results suggest that there might be a familial vulnerability in the endogenous melatonin signal in subjects prone to depression, and an abnormality in the duration of the melatonin signal in those with current major depression.

Aged↗

PubMed2002

Evening light exposure: implications for sleep and depression.

OBJECTIVES: To examine whether dim illumination in the evening is a factor in sleep disturbances of aging, depression, and circadian phase advance. DESIGN: One-week continuous recordings were made to record illumination exposure and to infer 24-hour sleep patterns from wrist activity. SETTING: Recordings took place during normal home and community activities. PARTICIPANTS: Complete data of 154 postmenopausal women, mean age 66.7, were selected from a larger study of participants in the Women's Health Initiative. MEASUREMENTS: Illumination in lux was averaged for 4 hours before bedtime and over 24 hours. Mood was measured using a brief eight-item screen. RESULTS: Illumination in the 4 hours before bedtime was quite dim: median 24 lux. Nevertheless, evening light exposure was not significantly related to sleep amount (in bed or out of bed) sleep efficiency, sleep latency, wake within sleep, or mood. In contrast, the overall amount of light throughout the 24 hours was negatively correlated with sleep latency, wake within sleep, and depressed mood. CONCLUSIONS: Low evening lighting does not appear to be a crucial factor in sleep and mood disturbances of aging, but overall lighting may contribute to these disturbances.

Aged↗

PubMed2002

Illumination of upper and middle visual fields produces equivalent suppression of melatonin in older volunteers.

Bright light treatment has become an important method of treating depression and circadian rhythm sleep disorders. The efficacy of bright light treatment may be dependent upon the position of the light-source, as it determines the relative illumination in each portion of the visual field. This study compared illumination of upper and middle visual fields to determine whether melatonin suppression is different or equivalent. Thirteen older volunteers received three illumination conditions in counterbalanced orders: 1000 lux in the upper visual field, 1000 lux in the middle visual field, or dim diffuse illumination < 5 lux. A four-choice reaction time task was performed during tests to ensure eye direction and illumination of the intended portion of the visual field. Illumination in the upper and middle visual fields significantly suppressed melatonin compared to < 5 lux (p < 0.001). Melatonin suppression was not significantly different with upper or middle field illumination. These results indicate that bright light treatments placed above the eye level might be as effective as those requiring patients to look directly at the light source. Clinical comparative testing would be valuable. In addition, this study demonstrates that significant suppression of melatonin may be achieved through the use of bright light in healthy older volunteers.

Aged↗

PubMed2002

Circadian phase-delaying effects of bright light alone and combined with exercise in humans.

In a within-subjects (n = 18), counterbalanced design, the circadian phase-shifting effects of 3 h of 1) bright light (3,000 lx) alone 2) and bright light combined with vigorous exercise were compared. For each treatment, volunteers spent 3 nights and 2 days in the laboratory, typically receiving the treatment from approximately 2300 to 0200 on night 2. Bedtimes and waketimes were fixed to the volunteers' habits. Illumination was 50 lx during other wake hours and 0 lx during sleep. Bright Light Alone elicited a significant phase delay in rectal temperature minimum (70 min), but not in urinary 6-sulphatoxymelatonin (6-SMT) acrophase (20 min). Bright Light + Exercise elicited a significant phase delay in 6-SMT (68 min), but did not result in a significant difference in shift compared with Bright Light Alone. The study had adequate statistical power (80%) to detect phase-shift differences between treatments of approximately 2-2.5 h. Thus any antagonism of light shifts with exercise could not have been revealed. Within the limited exercise and light parameters of this study, the results suggest that exercise does not reliably modulate phase-shifting effects of late night bright light in humans.

Adolescent↗

PubMed2002

Bright-light mask treatment of delayed sleep phase syndrome.

We treated delayed sleep phase syndrome (DSPS) with an illuminated mask that provides light through closed eyelids during sleep. Volunteers received either bright white light (2,700 lux, n = 28) or dim red light placebo (0.1 lux, n = 26) for 26 days at home. Mask lights were turned on (< 0.01 lux) 4 h before arising, ramped up for 1 h, and remained on at full brightness until arising. Volunteers also attempted to systematically advance sleep time, avoid naps, and avoid evening bright light. The light mask was well tolerated and produced little sleep disturbance. The acrophase of urinary 6-sulphatoxymelatonin (6-SMT) excretion advanced significantly from baseline in the bright group (p < 0.0006) and not in the dim group, but final phases were not significantly earlier in the bright group (ANCOVA ns). Bright treatment did produce significantly earlier phases, however, among volunteers whose baseline 6-SMT acrophase was later than the median of 0602 h (bright shift: 0732-0554 h, p < 0.0009; dim shift: 0746-0717 h, ns; ANCOVA p = 0.03). In this subgroup, sleep onset advanced significantly only with bright but not dim treatment (sleep onset shift: bright 0306-0145 h, p < 0.0002; dim 0229-0211 h, ns; ANCOVA p < .05). Despite equal expectations at baseline, participants rated bright treatment as more effective than dim treatment (p < 0.04). We conclude that bright-light mask treatment advances circadian phase and provides clinical benefit in DSPS individuals whose initial circadian delay is relatively severe.

Adolescent↗