The BRCA1 and BRCA2 breast cancer genes

This review discusses the need for sleep, effects of sleep deprivation on behaviour and performance in the military, and sleep management recommendations to optimise combat effectiveness. Most people, regardless of sex or race, prefer 7 to 8 hours of sleep each night. Sleeping during the day is less recuperative. Continuous sleep is more effective than multiple short naps-even when the total hours for naps is more. Ten to 20 minute naps are useful when continuous sleep is not possible. Sleep inertia is the 5 to 30 minute period of sluggishness after awakening and important military tasks should be avoided. Previously, continuous work episodes (CWEs) duration was restricted by limited night vision, unreliable equipment and reduced endurance of military personnel. With improved technology, CWEs are now restricted primarily by endurance which is affected by sleep deprivation. This was one of the experiences noted in recent conflicts (e.g. Desert Storm) by personnel in the air force, army and navy. Since there will be changes in operational requirements, several work-rest-sleep plans must be prepared. Sleeping the preferred 7 to 8 hours per 24 hours the week before an operation may help prepare for optimal performance. Personnel should be familiarised with conditions under which they may sleep. During combat, sleep management should ideally avoid situations where all personnel are exhausted at the same time. As sleep debt accumulates, a person's mood, motivation, attention, alertness, short-term memory, ability to complete routines, task performance (errors of omission more than errors of commission) and physical performance will become more negatively affected. Counter measures must then be taken (e.g. time for sleep or naps, changing routines or rotating jobs). Drugs like caffeine and amphetamine can help personnel stay awake. However, they may also keep them awake when they need to sleep- and on awakening, they could suffer from "hang-overs" and are less efficient. Sleep lost need not be replaced hour-for-hour. Therefore, after operations, personnel need continuous sleep for only 10 to 12 hours as longer sleep increases sleep inertia and delays getting back to normal schedules.     

Compensatory sleep responses to wakefulness induced by the dopamine autoreceptor antagonist (-)DS121

The effect of the dopamine autoreceptor antagonist (-)DS121 on wakefulness, locomotor activity, body temperature and subsequent compensatory sleep responses was examined in the rat. Animals entrained to a light-dark cycle were treated at 5 h after lights-on (CT-5) with 0.5, 1, 5 or 10 mg/kg i.p. (-)DS121 or methylcellulose vehicle. An additional group received 5 mg/kg i.p. (-)DS121 or vehicle 6 h after lights-off (CT-18). At CT-5, (-)DS121 dose-dependently increased wakefulness, locomotor activity and body temperature, and decreased both non-rapid eye movement sleep (NREM) and rapid eye movement sleep (REM) during the first 4 h post-treatment relative to vehicle controls. REM interference lasted up to 3 h longer than NREM. Low doses of (-)DS121 (0.5 and 1 mg/kg) produced relatively little waking that was not followed by significant compensatory sleep responses. In contrast, higher doses (5 and 10 mg/kg) produced compensatory hypersomnolence (robust increases in NREM immediately after the primary waking effect) that was proportional to the duration of drug-induced wakefulness. NREM recovery 24 h post-treatment was the same for the 5 mg/kg (65.4 +/- 9.9 min) and 10 mg/kg (64.8 +/- 9.3 min) doses, but was not proportional to prior wake duration. NREM displaced by drug-induced wakefulness was recovered completely by 24 h post-treatment at the 5 mg/kg dose, but only 63.5% recovered at 10 mg/kg. In contrast, equivalent wakefulness produced by sleep deprivation yielded 100% NREM recovery. At CT-18, (-)DS121 (5 mg/kg) increased wakefulness without disproportionately increasing locomotor activity, and was compensated fully by 24 h post-treatment. These data show that (-)DS121 dose-dependently increases wakefulness, which is followed by hypersomnolence that is proportional to drug-induced wake-promoting efficacy.     

The relationship of luteinizing hormone secretion to sleep in women during the early follicular phase: effects of sleep reversal and a prolonged three-hour sleep-wake schedule

The relationship of luteinizing hormone (LH) secretion to sleep in adult women was investigated in two ways: an acute 180 degrees sleep-wake cycle reversal in a group of six women and a schedule in which a young woman engaged in a three hour sleep-wake cycle (two hours awake, one hour allowed for sleep continuously for ten days--the study was carried out on the eighth day). Each subject in the reversal study had a baseline period during which plasma samples were collected every twenty minutes for twenty-four hours and nocturnal sleep was monitored electrophysiologically during the early follicular phase of the menstrual cycle. During a succeeding cycle, the study was repeated after sleep-wake reversal. LH secretory patterns were analyzed by comparing the 24-hour mean plasma LH concentration with the hourly averages in percentage terms, using Stage 2 sleep onset as the zero point. LH secretion was depressed to approximately the same degree in both the baseline and reversal studies. The average hourly percentage difference from the 24-hour mean for the four-hour period following sleep onset was -13.4% and -13.1% for the baseline and reversal, respectively. These percentage deviations represented practically the entire negative deviation for the 24-hour period in both studies. The difference between the first four-hour period after sleep onset and the second was significant. The subject on a three-hour cycle had a baseline in which a large decrease in LH secretion occurred after sleep onset (-52.2% during the third hour). Her LH secretory pattern during the three-hour sleep-wake schedule was characterized by a fall during sleep periods, particularly when slow wave sleep (SWS) predominated. However, no correlation was found between specific sleep stages and LH secretion in the six women of the reversal study. These results confirm a relationship of LH secretion to sleep in adult women, one which is different from that described during puberty.     

Sleep Deprivation and Its Consequences in Construction Workers

Sleep deprivation contributes to fatigue, which can have a profound effect on an individual’s wellbeing, work performance, and safety. To investigate this phenomenon, a study was conducted on a sample of construction workers on a large construction project in Vancouver, Canada. This paper reports on the results from the workers wearing an actigraph 24 h/day for a full week to precisely measure their sleep and rest. The results enabled sleep efficiency and mental effectiveness levels to be determined by correlating them to blood alcohol concentration levels. This allowed determination of increased risk due to inadequate sleep. It was found that workers fell well under recommended sleep requirement guidelines of 8-h sleep per night, which resulted in an increase in risk of accident of 9%. Although further work is needed to better understand the coping mechanisms of fatigue and how the resulting fatigue factor could be measured and managed, this study indicates that workers in the construction industry suffer decrements in performance and are at higher risk of accident at home and work solely due to inadequate sleep.     

Phase II study of 3-hour infusion of paclitaxel in previously untreated non-small cell lung cancer

Paclitaxel has clinical activity in non-small cell lung cancer, with response rates of 21 and 24% in a 24-h infusion. Recent clinical studies have shown that a 3-h infusion of the drug with premedication did not result in hypersensitivity reactions, and that neutropenia was milder in the 3-h than in the 24-h schedule. In this Phase II study, we tried to evaluate the efficacy and toxicity of paclitaxel given over 3 h in patients with previously untreated, unresectable stage III or IV non-small cell lung cancer. In addition, we attempted to investigate the pharmacokinetics and pharmacodynamics of the drug. Paclitaxel was administered i.v. over 3 h at a dose of 210 mg/m2 every 3 weeks with premedication of dexamethasone, ranitidine, and diphenhydramine. Heparinized blood samples were obtained from 12 patients for pharmacokinetic studies. Twenty-three (38%) of 60 assessable patients achieved a partial response, with a median duration of 3.2 (range, 2.3-11.1) months. The median survival for all patients was 11.2 months, and the 1-year survival rate was 48%. Thirty (50%) patients developed grade 4 neutropenia. Nonhematological toxicities were mild, except for pulmonary toxicity in one (1.7%) patient who required mechanical ventilatory support for 4 days. The duration of the paclitaxel concentration above 0.1 microM correlated well with the percentage of decrease in the absolute neutrophil count. In conclusion, a 3-h infusion of paclitaxel was safe and probably not less effective than a 24-h infusion.     

Circadian and ultradian variations of leptin in normal man under continuous enteral nutrition: relationship to sleep and body temperature

To determine the influence of circadian rhythmicity and sleep on the 24-h leptin diurnal variations, plasma leptin levels were measured at 10-min intervals over 24 h in seven normal subjects, once during nocturnal sleep, and once after an 8-h shift of sleep. The subjects were submitted to constant conditions (continuous enteral nutrition and bed rest in controlled chambers). Body temperature and plasma glucose and insulin levels were measured simultaneously. During nighttime sleep, leptin levels increased to a maximum (109.9 +/- 2.5% of the 24-h mean) and then decreased to reach a nadir in the late afternoon. The mean diurnal variation was 18.0 +/- 3.8% of the 24-h mean. In the daytime sleep condition, leptin levels rose during the night of deprivation to a maximum of 104.7 +/- 2.3% of the 24-h mean, decreased to a minimum around 0700 h, and then rose again during diurnal sleep (108.4 +/- 3.1% of the 24-h mean); the mean diurnal variation was 13.4 +/- 3.6% of the 24-h mean. ANOVA revealed a significant interaction between time of day and sleep effects (P < 0.05). The diurnal and the sleep-related variations of plasma leptin mirrored those of body temperature and roughly paralleled those of plasma glucose and insulin; the amplitudes of the diurnal leptin variations were significantly correlated with the amplitudes of the diurnal body temperature variations (P < 0.05). Plasma leptin levels also displayed irregular pulses of low amplitude (mean duration, 70 min) that were not affected by sleep, but were associated with a significant decrease in glucose and insulin levels (P < 0.01). These results demonstrate that under continuous enteral nutrition, plasma leptin levels are modulated by both a slight circadian component and sleep, which interact under normal conditions, and suggest that leptin is implicated in circadian thermoregulatory adjustments.     

Chronobiologic features in a 12-hour working day

A review of investigations into the effects of 12-hour workdays indicates that the extended workday is frequently related to decrement of performance efficiency, alertness and safety, and to increased subjective fatigue during work. Fatigue is increased even more during night shift work. As sleep duration after the night shift is also reduced, combined effects of fatigue and sleep debt can increase the risk of accidents, especially when workers work more nights in a row. In spite of the increased feeling of fatigue the workers prefer longer working hours to an eight-hour working schedule, because they have more free time to use for restitution, leisure and other domestic and second job activities.     

Compliance in treatment of the sleep apnea syndrome using continuous positive pressure respiration

BACKGROUND: Continuous positive airway pressure (CPAP) is the therapeutic method of choice in sleep apnoea syndrome (SAS) but involves at first discomfort for the patients. The correct indication, correct setting of the overpressure and good adaptation influence the application and therapeutic asset of CPAP. METHODS AND RESULTS: From a total number of 41 patients with SAS treated by CPAP 24 were examined (incl. three women), who had CPAP in domiciliary treatment for more than two months. The mean period of use was 288.2 days (range 52-824). 84% of the patients used CPAP daily, the mean number of applications per week was 6.26 (range 2-7). For the whole period of sleep CPAP was used by 75% patients and the mean sleep period with CPAP was 6 hours (range 2.5-8). None of the patients discontinued treatment completely. Four patients used CPAP inadequately (less than 25 hours per week) - one because of intolerance associated with severe CHOCHB, the second one for intolerance of overpressure of 15 mbar, the third one because of poor motivation and the fourth one because of dehydration of mucous membranes. All patients recorded the therapeutic effect of CPAP. Rhonchopathy disappeared in 87.5% patients, excessive somnolence improved in 91.7%, fatigue declined in 88.5%. The functional capacity and work performance improved in 95.8% patients. Undesirable effects were not serious nor frequent: escape of air from the mask (29.2%), dry mucosae (20.8%), pressure sores caused by the mask (20.8%), serous rhinitis (12.5%), burning sensation of the mucosae of the upper airways (8.3%) and conjunctivitis (4.2%) CONCLUSIONS: Adequate compliance with CPAP was recorded in 83.3% patients and a favourable effect of treatment was proved.     

Circadian rhythms during gradually delaying and advancing sleep and light schedules

The circadian rhythms of the night shift worker show very little phase shift in response to the daytime sleep and night work schedule. One strategy for producing circadian adaptation may be to use appropriately timed exposure to high-intensity light. We attempted to shift the circadian temperature rhythms of seven normal subjects while they followed a sleep schedule that gradually delayed (2 h per day) until sleep occurred during the daytime, as is customary for workers during the night shift. After 5 days, the sleep schedule was gradually advanced back to baseline. High illuminance light (2 h per day) and the attenuation or avoidance of sunlight were timed to facilitate temperature rhythm phase shifts. In general, the temperature rhythm did not shift along with the sleep-wake schedule, but appeared either to free run or remain entrained to the natural 24-h zeitgebers. This study showed how difficult it can be to shift human circadian rhythms in the field, when subjects are exposed to competing 24-hr zeitgebers.     

Sleep schedules and daytime functioning in adolescents

Sleep and waking behaviors change significantly during the adolescent years. The objective of this study was to describe the relation between adolescents' sleep/wake habits, characteristics of students (age, sex, school), and daytime functioning (mood, school performance, and behavior). A Sleep Habits Survey was administered in homeroom classes to 3,120 high school students at 4 public high schools from 3 Rhode Island school districts. Self-reported total sleep times (school and weekend nights) decreased by 40-50 min across ages 13-19, ps < .001. The sleep loss was due to increasingly later bedtimes, whereas rise times were more consistent across ages. Students who described themselves as struggling or failing school (C's, D's/F's) reported that on school nights they obtain about 25 min less sleep and go to bed an average of 40 min later than A and B students, ps < .001. In addition, students with worse grades reported greater weekend delays of sleep schedule than did those with better grades. Furthermore, this study examined a priori defined adequate sleep habit groups versus less than adequate sleep habit groups on their daytime functioning. Students in the short school-night total sleep group (< 6 hr 45 min) and/or large weekend bedtime delay group (> 120 min) reported increased daytime sleepiness, depressive mood, and sleep/wake behavior problems, ps < .05, versus those sleeping longer than 8 hr 15 min with less than 60 min weekend delay. Altogether, most of the adolescents surveyed do not get enough sleep, and their sleep loss interferes with daytime functioning.     

Twenty-four-hour ambulatory oxygen desaturation and electrocardiographic recording in obstructive sleep apnea syndrome

BACKGROUND: Although nocturnal pulseoximetry is routinely performed in obstructive sleep apnea syndrome (OSAS), pulseoximetry over a 24-h period has not been studied. HYPOTHESIS: The purpose of the study was to determine whether simultaneous 24-h oxygen desaturation and electrocardiographic (ECG) recording might be used to screen for daytime sleep sequelae in patients with OSAS. METHODS: Simultaneous recording of arterial oxygen saturation (SpO2) and ECG was conducted over a 24-h period in 18 male patients with OSAS (mean age 51.3 years) who were diagnosed by standard polysomnography (PSG), and in 15 age-matched healthy subjects (mean age 52.7 years) as controls to evaluate circadian variation of these parameters. The measures of heart rate variability (HRV) were calculated from 24-h ambulatory ECGs. Seventeen patients with OSAS showed excessive daytime sleepiness (EDS). We calculated the duration in which SpO2 decreased to < 90% (duration of SpO2 < 90%). The number of apnea/hypopneas per hour (AHI) during sleep was investigated with Apnomonitors (Chest MI, Co., Tokyo) on the same day as the SpO2 recordings. RESULTS: Controls showed no episodes of oxygen desaturation. In patients with OSAS, driving (33.3% of patients with OSAS) was the most common activity in which SpO2 decreased to < 90%, followed by daytime napping (27.8%) and resting after meals (22.2%). The duration of SpO2 < 90% over a 24-h period correlated significantly with the duration levels recorded during sleep (r = 0.99, p < 0.05) and in the afternoon (r = 0.62, p < 0.05), and with the AHI (r = 0.55, p < 0.05), but not with the duration of SpO2 < 90% in the morning. The number of ventricular premature beats correlated significantly with the duration of SpO2 < 90% for a 24-h period, but not with measures of HRV. Ventricular tachycardia was found in two (11.1%) and ST-T depression in three patients (16.6%) with underlying cardiac diseases. CONCLUSION: Our results suggest that daytime sleep attacks accompanied by oxygen desaturation in patients with moderate to severe OSAS may contribute to the occurrence of traffic or cardiovascular accidents. We conclude that 24-h ambulatory recordings of SpO2 and ECG are useful for screening for daytime sleep sequelae associated with the potential risk of this pathology in OSAS during social activities.     

Non-24-hour sleep-wake syndrome in a sighted man: circadian rhythm studies and efficacy of melatonin treatment

The case of a 41-year-old sighted man with non-24-hour sleep-wake syndrome is presented. A 7-week baseline assessment confirmed that the patient expressed endogenous melatonin and sleep-wake rhythms with a period of 25.1 hours. We sought to investigate the underlying pathology and to entrain the patient to a normal sleep-wake schedule. No deficiency in melatonin synthesis was found. Furthermore, normal coupling between the melatonin and sleep propensity rhythms was documented using an "ultrashort" sleep-wake protocol. Environmental light exposure was monitored for 41 days, and the circadian timing was calculated. Sensitivity to photic input was determined with light-induced melatonin-suppression tests. Three intensities (500, 1,000, and 2,500 lux) were examined during three separate trials. The 2,500-lux trial resulted in 78% suppression, but the lesser intensity exposures were without substantial effect. Thus, the patient appeared to be subsensitive to bright light. A 4-week trial of daily melatonin administration (0.5 mg at 2100 hours) stabilized the endogenous melatonin and sleep rhythms to a period of 24.1 hours, albeit at a somewhat delayed phase. A 14-month follow-up interview revealed that the patient continued to take melatonin daily, and his sleep-wake schedule was stable to a near 24-hour schedule.     

Physiological comparison of three interventions in light assembly work: reduced work pace, increased break allowance and shortened working days

An industrial assembly task known to imply a high risk for shoulder-neck disorders was simulated in the laboratory. Eight females (aged 22-32 years) were trained to manage industrial work pace (120 according to the methods-time measurement system, MTM). They carried out seven work protocols at different days with different combinations of work pace (120 or 100 MTM), break allowance (20 min of active or passive breaks added every 2 h), and duration of the working day (2, 4 or 6 h). During 6 h of work at 120 MTM the electromyographic (EMG) amplitude from the upper trapezius muscle increased by about 11%, the EMG zero crossing rate decreased by about 2.5%, and perceived fatigue increased by about 4 CR10 scale units. When work pace was reduced to 100 MTM, the upper trapezius EMG amplitude decreased by 20% and became less variable. Heart rate decreased by about 10 bpm, perceived fatigue decreased by about 1 CR10 scale units, and shoulder tenderness was reduced by about 5%. However, the work task could still not be performed in a physiological steady state. Added breaks, whether active or passive, had no apparent effects on upper trapezius load during work or on physiological responses. Recovery of EMG, maximal strength, heart rate and blood pressure sensitivity, and tenderness was complete 4 h after work, independent of the preceding work conditions. These findings suggest that a limitation of the daily duration of assembly work may be more effective in limiting acute fatigue than reduced work pace or increased break allowance.     

The influence of a heavy thermal load on REM sleep in the rat

This study was carried out in order to further test the hypothesis that the occurrence of REM sleep in the rat in the form of episodes separated by long intervals (single REM sleep episodes) and by short intervals (sequential REM sleep episodes) is differently influenced by changes in both sleep and ambient related processes. Rats were studied during the exposure to Ta -10 degrees C for 24 or 48 h and during a 12 h recovery period at laboratory Ta (23 degrees C) following either the first or the second 24 h of cold exposure. The exposure to such a low Ta induced an almost complete abolition of REM sleep which was followed, during recovery, by a marked REM sleep rebound. However, in spite of the larger REM sleep deprivation, the REM sleep rebound was weaker following the 48 h-exposure than that following the exposure for 24 h. The increase in the amount of REM sleep during the recovery period was due to an increase in the amount of that occurring in the form of sequential episodes, whilst that in the form of single episodes did not change with respect to control levels. However, the occurrence of REM sleep in the form of sequential episodes was partially impaired during the REM sleep rebound observed in the recovery period following the 48 h-exposure. These results would suggest that the homeostatic regulation of physiological variables may conflict with that of REM sleep occurrence and that the degree of such a contrast is indicated, at low Ta, by the amount of REM sleep in the form of single episodes and, during the following recovery, by the amount of REM sleep in the form of sequential episodes.     

The effects of frequently rotating shiftwork on sleep and the family life of hospital nurses

The effects of three frequently rotating shifts in an irregular sequence on the daily activities of 239 Japanese female hospital nurses were studied by the time-budget method. The nurses recorded their daily activities for several consecutive days. The questionnaire was returned by 80.8% of the participants, and recordings of 1016 days were analysed. A two-way analysis of variance clarified that the shift combination influenced the daily activities. The most distinct result was that nurses spent significantly more time on free-time activities on the day when they worked the night shift followed by the evening shift than they did on the day when they worked any other shift combination. Nurses offset sleep deprivation either by sleeping during the day before and after working the night shift (82-100%) or by sleeping 2 to 4 h later in the morning after working the evening shift and on days off. There was a strong positive correlation between total sleep time (including day sleep) and the length of the interval between two consecutive shifts (r = 0.95, p < 0.001). This result suggests that more than 16 h between work shifts is required to allow more than 7 h of total sleep time. In an analysis by household status, nurses who had young children (average age, 2.8 years) slept less and spent less time on free-time activities than did other nurses.     

Companionable sleep: Social regulation of sleep and cosleeping in egyptian families.

This exploratory study examined family sleep patterns and quality in a setting of normative napping and cosleeping. Participants were 78 members of 16 families from 2 locales in Egypt (Cairo and a village). Each family member provided a history of sleeping arrangements, 1 week of continuous activity records, and details of each sleep event. Sleep records documented late-onset and dispersed sleep patterns with extensive cosleeping. Of recorded sleep events, 69% involved cosleeping, 24% included more than 1 cosleeper, and only 21% were solitary. Mid-late afternoon napping occurred on 31% of days, and night sleep onsets averaged after midnight. Age and gender structured sleep arrangements and, together with locale, extensively explained sleep behavior (onset, duration, total) and quality. Cosleepers had fewer night arousals, shorter and less variable night sleep duration, and less total sleep. Increased solitary sleep in adolescents and young adults was associated with increased sleep dysregulation, including exaggerated phase shifts in males and more nighttime arousals in females. Where normative, cosleeping may provide psychosensory stimuli that moderate arousal and stabilize sleep. Such moderating features may address important self-regulatory developmental needs during adolescence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sleep quality in Lyme disease

Complaints of chronic fatigue as well as sleep disturbances are prevalent in Lyme disease. We compared polysomnographic measures of sleep in patients with documented Lyme disease with those of a group of age-matched normal control subjects. Eleven patients meeting Centers for Disease Control criteria for late Lyme disease with serologic confirmation by enzyme-linked immunosorbent assay and Western blot without a history of other medical or psychiatric illness and 10 age-matched control subjects were studied. Lyme disease patients and controls underwent 2 nights of polysomnography. Multiple sleep latency testing (MSLT) was performed in the patients. Sleep was staged by standard criteria, and continuity of sleep was assessed for each stage of frequency analysis of consecutive epochs. All patients studied reported sleep-related complaints, including difficulty initiating sleep (27%), frequent nocturnal awakenings (27%), excessive daytime somnolence (73%) and restless legs/nocturnal leg jerking (9%). Greater sleep latency, decreased sleep efficiency and a greater arousal index were noted in Lyme patients. The median length of uninterrupted occurrences of stage 2 and stage 4 non-rapid eye movement (NREM) sleep was less in Lyme patients (6.3 +/- 3.0 epochs in patients vs. 11.4 +/- 4.4 epochs in controls for stage 2, p < 0.01, and 4.3 +/- 4.4 epochs in patients vs. 11.2 +/- 6.3 epochs in controls for stage 4, p < 0.01), indicating greater sleep fragmentation. Mean sleep onset latency during the MSLT was normal (12.7 +/- 5.6 minutes). Three patients demonstrated alpha-wave intrusion into NREM sleep. These sleep abnormalities may contribute to the fatigue and sleep complaints common in this disease.     

A randomized crossover study of an oral appliance vs nasal-continuous positive airway pressure in the treatment of mild-moderate obstructive sleep apnea

STUDY OBJECTIVE: To compare efficacy, side effects, patient compliance, and preference between oral appliance (OA) therapy and nasal-continuous positive airway pressure (N-CPAP) therapy. DESIGN: Randomized, prospective, crossover study. SETTING: University hospital and tertiary sleep referral center. PATIENTS: Twenty-seven unselected patients with mild-moderate obstructive sleep apnea (OSA). INTERVENTIONS: There was a 2-week wash-in and a 2-week wash-out period, and 2 x 4-month treatment periods (OA and N-CPAP). Efficacy, side effects, compliance, and preference were evaluated by a questionnaire and home sleep monitoring. MEASUREMENTS AND RESULTS: Two patients dropped out early in the study and treatment results are presented on the remaining 25 patients. The apnea/hypopnea index was lower with N-CPAP (3.5 +/- 1.6) (mean +/- SD) than with the OA (9.7 +/- 7.3) (p < 0.05). Twelve of the 25 patients who used the OA (48%) were treatment successes (reduction of apnea/hypopnea to <10/h and relief of symptoms), 6 (24%) were compliance failures (unable or unwilling to use the treatment), and 7 (28%) were treatment failures (failure to reduce apnea/hypopnea index to <10/h and/or failure to relieve symptoms). Four people refused to use N-CPAP after using the OA. Thirteen of the 21 patients who used N-CPAP were overall treatment successes (62%), 8 were compliance failures (38%), and there were no treatment failures. Side effects were more common and the patients were less satisfied with N-CPAP (p < 0.005). Seven patients were treatment successes with both treatments, six of these patients preferred OA, and one preferred N-CPAP as a long-term treatment. CONCLUSIONS: We conclude that OA is an effective treatment in some patients with mild-moderate OSA and is associated with fewer side effects and greater patient satisfaction than N-CPAP.     

Low-dose amiodarone versus sotalol for suppression of recurrent symptomatic atrial fibrillation

The goal of this work is to study the consequences of the last on variations of the blood pressure (BP) in the course of 24 hours. From 1994 to 1997 we have selected 99 hypertensive patients and studied their BP profile. This study included 72 women and 27 men. Their age varies from 22 to 72 years (average 56.7 +/- 9 years). All these patients has an ambulatory blood pressure measurement (ABPM) before the fast and during Ramadan. Before Ramadan the period of the sleep goes from 10 pm +/- 1 h to 8 am +/- 1 h. During the month of Ramadan, the sleep lasts from 0 h +/- 1 to 9 am +/- 1 h. [table: see text] No statistically significant difference is noted between these 2 periods neither for the systolic BP (SBP) nor for the diastolic BP (DBP), for the BP of 24 hours, and the diurnal and nocturnal periods. We have then the compared the hourly average on 24 hours of the 99 patients. We observed that during the month of Ramadan the peak of the awakening is delayed by 2 hours and the nocturnal through is delayed by 1 hour. After this study, which is the first one to deal with variations of blood pressure during the fast of Ramadan we can confirm that in patients with essential hypertension without complications, the fast is well supported. The variations of BP are minimal and are related to the variations of the sleep, activity and eating pattern.     

Sleep patterns, shiftwork, and individual differences: a comparison of onshore and offshore control-room operators

The sleep patterns of offshore control-room operators were compared with those of personnel carrying out similar work onshore, taking into account individual differences in age, number of years of shiftwork, and neuroticism. The dependent variables were self-reported sleep quality and duration for day-shift (D-S) and night-shift (N-S) work, and during leave periods (L-P). Offshore workers reported longer N-S sleep duration, and lower D-S sleep quality than those onshore, but the two groups did not differ in L-P measures. The effects of environmental differences (onshore versus offshore) on sleep patterns were more marked than those of the two different shift systems (weekly rotation and fast rotation) in operation onshore. Age was negatively related to both duration and quality of sleep; over and above age, number of years of shiftwork was negatively related to sleep duration. Neuroticism was also negatively related to sleep duration and, more strongly, to sleep quality. These findings are discussed in relation to the literature on shiftwork and sleep in general, and the characteristics of the offshore environment in particular.