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Biomedical subjects

D F Kripke

Publications and source records attributed to D F Kripke.

At least 73 records · Page 4Linked to original sources
PubMed1991

Sleep-disordered breathing in community-dwelling elderly.

These are the final results of a survey of sleep-disordered breathing, which examined objective and subjective information from a large randomly selected elderly sample. We randomly selected 427 elderly people aged 65 yr and over in the city of San Diego, California. Twenty-four percent had an apnea index, AI, greater than or equal to 5 and 62% had a respiratory disturbance index, RDI, greater than or equal to 10. Correlates of sleep-disordered breathing included high relative weight and reports of snoring, breathing cessation at night, nocturnal wandering or confusion, daytime sleepiness and depression. Body mass index, falling asleep at inappropriate times, male gender, no alcohol within 2 hr of bedtime and napping were the best predictors of sleep-disordered breathing. Despite statistical significance, all of the associations between interview variables and apnea indices were small. No combination of demographic variables and symptoms allowed highly reliable prediction of AI or RDI.

Aged↗
PubMed1991

Periodic limb movements in sleep in community-dwelling elderly.

The prevalence of periodic limb movements in sleep (PLMS) in a randomly selected elderly sample is reported. In San Diego, 427 elderly volunteers aged 65 yr and over were recorded in their homes. Forty-five percent had a myoclonus index, MI greater than or equal to 5. Correlates of PLMS included dissatisfaction with sleep, sleeping alone and reported kicking at night. Although statistically significant, the strengths of the associations between interview variables and myoclonus indices were all small. No combination of demographic variables and symptoms allowed highly reliable prediction of PLMS.

Aged↗
PubMed1991

Dementia in institutionalized elderly: relation to sleep apnea.

Sleep apnea is characterized by transient hypoxemias which are thought to affect mental functioning. Accordingly, speculation and research have focussed on relationships between sleep apnea and dementia. We studied 235 nursing home (ie institutionalized) patients (152 women with a median age of 83.5; 83 men with a median age of 79.7) with portable sleep recording equipment. The Mattis Dementia Rating Scale and the Geriatric Depression Scale were given to each. Seventy percent of the patients had five or more respiratory disturbances per hour of sleep and 96 percent showed some dementia. Sleep apnea was significantly correlated with all subscales on the dementia rating scale. There were trivial differences in dementia ratings between those with mild-moderate apnea and those with no apnea. There were significant differences, however, between the latter two groups and those with severe apnea. In particular, items reflecting attention, initiation and perseveration, conceptualization, and memory tasks on the DRS distinguished between those with and without severe sleep apnea. Among those patients with no depression, all patients with severe sleep apnea were also severely demented. Our data suggest that there is a strong relationship between dementia and sleep apnea when the sleep apnea and dementia are severe. Although causality cannot be inferred from associations, our hypothesis for study is that sleep apnea causes deficits in brain function, possibly due to global effects rather than any particular cortical or subcortical structure.

Aged↗
PubMed1991

Potassium affects actigraph-identified sleep.

The present study examines the effects of potassium supplementation on sleep quality and phase, as indirectly inferred from wrist actigraphy and sleep logs, in normal young males on a low-potassium diet. A randomized, double-blind, placebo-controlled, counterbalanced crossover design compared 1 wk of oral potassium chloride supplements (96 meq/day) to 1 wk of identical placebo capsules. Outcome measures were taken from sleep logs and wrist actigraphy. Sleep was indirectly inferred from wrist-actigraph data using a computer algorithm. Potassium supplementation significantly delayed sleep-log-identified Bedtime (p less than 0.001). Potassium reduced Sleeping Interval for both sleep-log (p less than 0.01) and wrist-actigraph (p less than 0.1) data. Potassium significantly increased actigraphic Sleep Efficiency (p less than 0.05) due to a reduction in actigraphic Wake after Sleep Onset (WASO) (p less than 0.05). No effect of potassium on actigraphic sleep phase was observed. Side effects were minimal and not significantly different between treatment conditions. The results may indicate an improvement in sleep consolidation with potassium supplementation. Further studies using standard polysomnography are required to define potassium's effects on human sleep.

Adult↗
PubMed1990

EEG sleep studies in "pure" primary alcoholism during subacute withdrawal: relationships to normal controls, age, and other clinical variables.

Electroencephalogram (EEG) sleep recordings were compared in 34 normal controls and 31 inpatients with relatively pure primary alcoholism who had been abstinent for about 17 days. Compared with normal controls, primary alcoholics took longer to fall asleep, slept less, and had poor sleep efficiency. Sleep loss reflected reduced non-rapid eye movement (NREM) sleep, especially stage 2 sleep, stage 4 sleep, and total delta (stage 3 and 4) sleep. Alcoholic patients had higher REM density of the first REM period. Sleep deteriorated with age in both normal controls and patients, with younger alcoholics showing sleep patterns typical of older controls. Among other clinical-demographic variables examined, the shorter the duration of sobriety at the time of the study, the later patients went to bed and fell asleep. The number of drinks per drinking day in the 3 months before admission was directly related to the duration of the first REM period. In addition, the maximum number of withdrawal symptoms the patient had ever experienced was inversely related to the amount of delta sleep. Sleep measures were not correlated with depression rating, liver enzymes, or other measures of alcohol consumption.

Adult↗
PubMed1990

Altered waveform of plasma nocturnal melatonin secretion in premenstrual depression.

The nocturnal secretion of plasma melatonin was determined under dim to dark conditions in eight patients with prospectively confirmed premenstrual syndrome and in eight age- and menstrual cycle phase-matched normal control subjects. Plasma samples for melatonin were collected every 30 minutes from 6 PM to 9 AM during the early follicular, late follicular, midluteal and late luteal phases of the menstrual cycle. Compared with normal controls, patients with premenstrual syndrome had an earlier (phase-advanced) offset of melatonin secretion, which contributed to a shorter secretion duration and a decreased area under the curve. No statistically significant differences were found between women with premenstrual syndrome and normal controls for melatonin onset or peak concentration, or for estradiol or progesterone levels. The data demonstrate that women with premenstrual syndrome have chronobiological abnormalities of melatonin secretion. The fact that these patients respond to treatments that affect circadian physiology, such as sleep deprivation and phototherapy, suggests that circadian abnormalities may contribute to the pathogenesis of premenstrual syndrome.

Adult↗
PubMed1990

Melatonin suppression in bipolar and unipolar mood disorders.

Nocturnal melatonin suppression to 500 lux light was studied during an acute episode of illness in 8 patients with bipolar disorder, 7 patients with unipolar depression, and 15 age-, sex-, and season-matched normal controls. Unipolar patients did not differ from controls in melatonin suppression. In contrast to previous studies, controls showed greater melatonin suppression than bipolar patients. Baseline melatonin concentration, however, was significantly lower in the bipolar group compared to the unipolar and control groups.

Bipolar Disorder↗
PubMed1990

Night light alters menstrual cycles.

Dewan asserted 20 years ago that a bedside light could shorten and regularize the menstrual cycle among women with long and irregular menstrual patterns. To replicate this, seven volunteers slept with a 100-watt bulb by the bedside from days 13-17 of their menstrual cycles, while nine controls similarly used a dim red placebo (photographic safe light). Indeed, the 100-watt bulbs shortened menstrual cycles from a mean of 45.7 days to 33.1 days and reduced variability, but the placebo had no effect. These results suggest that light may have promise for treatment of infertility, for contraception, and for other endocrine interventions.

Adolescent↗
PubMed1990

Short REM latency in primary alcoholic patients with secondary depression.

Primary alcoholic patients with secondary depression had significantly shorter REM latency and less non-REM sleep than alcoholics without other psychiatric diagnoses and normal control subjects. Both patient groups had significantly longer sleep latency and less sleep efficiency, total sleep time, and delta sleep than control subjects.

Adult↗
PubMed1990

Sleep evaluation in chronic insomniacs during 14-day use of flurazepam and midazolam.

This article contains the sleep results of the efficacy study of flurazepam 30 mg and 15 mg, midazolam 15 mg, and placebo in the 99 chronic insomniacs studied as part of this multicenter study. After a 20-day drug washout, all-night sleep was recorded on 2 baseline nights, on the first 2 treatment nights, on treatment night 7, and on the last 2 nights of the study (nights 13 and 14). To reduce the number of comparisons, electroencephalographic (EEG) sleep latency, EEG wake time, EEG sleep efficiency, post-sleep questionnaire (PSQ) sleep latency, and PSQ total sleep were preselected as the major sleep variables. Between-groups comparisons indicated that, when compared with the placebo control, all drugs improved sleep, but differences were statistically significant only for the first 2 nights, i.e., the early interval. Midazolam was more effective than either dose level of flurazepam on treatment night 1. Within-group analyses indicated that all drug groups showed significantly improved sleep from baseline throughout drug administration, but the placebo group did not significantly improve from baseline by either objective or subjective measures at any of the three time intervals. The sleep of patients taking flurazepam 30 mg did not differ significantly from the sleep of those receiving the 15 mg dose for any of the five major sleep variables at any interval. Objective EEG and subjective PSQ sleep variables showed significant positive correlations.

Adult↗
PubMed1989

Potassium advances circadian activity rhythms: interactions with lithium.

Lithium delays the circadian rhythm of wheel-running in Syrian hamsters at plasma concentrations (0.59-0.74 mM) that also cause toxic weight loss. A moderate elevation of dietary potassium (up to 6 times normal intake) prevented lithium-induced weight loss in a dose-dependent manner, but had no effect on the delay of activity rhythms caused by lithium. Without lithium, the highest level of potassium intake advanced activity rhythms by 1 h relative to an entraining light:dark cycle. These results suggest that lithium's toxic, but not behavioral, actions involve an interaction with potassium ion. Furthermore, dietary potassium supplementation might have independent uses as treatment for chronobiological disorders.

Animals↗
PubMed1989

Lithium delays circadian phase of temperature and REM sleep in a bipolar depressive: a case report.

The effects of lithium on the circadian rhythms of body temperature and rapid eye movement (REM) sleep were examined in a patient with bipolar depression. The acrophase of body temperature showed a phase delay of 74 min after 1 week of lithium treatment. REM latency increased significantly with lithium, and the onset of subsequent REM periods was also delayed. The proportion of the night spent in REM sleep decreased significantly. There was no effect of lithium on the patient's mood. The data are consistent with the hypothesized phase-delaying properties of lithium but do not support the causal link between circadian phase and affective state.

Bipolar Disorder↗
PubMed1989

Effects of brief naps on mood and sleep in sleep-deprived depressed patients.

To determine the effects of brief naps on mood and electroencephalographic (EEG) sleep in sleep-deprived depressed patients, data from 19 hospitalized patients with depression were analyzed; all were kept awake from 0700h until the following day, when they were allowed 10-min naps at either 0830h or 1500h. Six of the patients showed a clinically significant improvement (greater than 40% change) on the Hamilton Rating Scale for Depression (HRSD) before the nap after all-night sleep deprivation, and the group as a whole showed a significant improvement on the HRSD, the Profile of Mood States, and the Brief Psychiatric Rating Scale subscale for depression. Naps did not alter mood in the responders, but did improve measured depression on the HRSD in the non-responders. Morning and afternoon naps did not differ significantly in their effects on mood or nap sleep. On the recovery sleep, patients who were classified as responders after the nap showed a significantly greater increase in delta (Stage 3 + 4) sleep compared with baseline than nonresponders.

Affect↗
PubMed1989

Light suppression of melatonin in unipolar depressed patients.

The effects of nocturnal light (500 lux) exposure on plasma melatonin were studied in seven men suffering from unipolar depression and in seven healthy men. Both groups showed significant declines in plasma melatonin concentrations during 1 hour's light exposure. Differential group declines were not detected.

Adult↗
PubMed1989

Biological effect of bright light.

1. Five minute bright light exposures reduced plasma levels of melatonin in eight normal subjects. 2. No significant change in ACTH levels occurred. 3. These results raise the possibility that short intense light exposures can synchronize circadian rhythms as well as benefit patients with seasonal affective disorder. They also indicate that short pulses of bright light do not affect pituitary ACTH production.

Adrenocorticotropic Hormone↗
PubMed1989

Twenty-four-hour sleep-wake patterns in a nursing home population.

Sleep-activity patterns were objectively recorded over a 24-hr period in 19 elderly nursing home residents. On average, both sleep and wake times were observed during every hour of the 24 recorded hours; however, the sleep pattern of the residents was fragmented so that they rarely experienced even a single hour of consolidated time spent sleeping. It is hypothesized that several independent factors, including compensation for lost sleep, increased total time in bed, weakening of social constraints, and deterioration of the circadian sleep-wake rhythm, are interacting to produce this increase in sleep fragmentation.

Activities of Daily Living↗