Immune disruptions and night shift work in hospital healthcare professionals: The intricate effects of social jet-lag and sleep debt.

Objectives: We aimed to examine the effects of circadian and sleep rhythm disruptions on immune biomarkers among hospital healthcare professionals working night shifts and rotating day shifts. Methods: Hospital nurses working either as permanent night shifters (n=95) or as day shifters rotating between morning and afternoon shifts (n=96) kept a daily diary on their sleep and work schedules over a full working week. Blood samples were collected at the beginning and end of the last shift during the week, and participants were categorized into three groups based on work shift: morning shift (39 day shifters sampled at 7:00 and 14:00), afternoon shift (57 day shifters sampled at 14:00 and 21:00), and night shift (95 night shifters sampled at 21:00 and 7:00). Circulating blood counts in immune cells, interleukin-6 and C-reactive protein concentrations as well as total sleep time per 24 hours during work days (TST24w) and free days (TST24f), sleep debt (TST24f - TST24w) and social jet-lag (a behavioral proxy of circadian misalignment) were assessed. Results: Compared with day shifters, night shifters had shorter sleep duration (TST24w=5.4 ± 1.4h), greater sleep debt (3.2 ± 1.4 h) and social jet-lag (6.7 ± 2.4 h). Variations of immune biomarkers concentrations were consistent with the expected diurnal variations among day shifters (i.e., low level in the morning, increase during the day, peak value in the evening). By contrast, in night shifters, blood concentrations of total lymphocytes, T-helper cells, cytotoxic T-cells, memory B-cells and interleukin-6 were lower at 21:00, increased during the night, and reached higher values at 7:00. Multivariate analyses ruled out significant impact of TST24w, sleep debt, and social jet-lag on immune biomarkers concentrations among day shifters. In contrast, among night shifters, multivariate analyses indicated a combined effect of total sleep time (TST24w), sleep debt and social jet-lag for total lymphocytes and T-helper cells but only a social jet-lag effect for interleukin-6 and a single total sleep time effect for neutrophil and B-Cells. Conclusions: Altogether, our results point to intricate response patterns of immune rhythms to circadian misalignment and sleep debt in night shifters. Specifically, these altered pattern expressions of immune cells may increase vulnerability to infections and reduce vaccination efficiency in night workers.

Digital circadian and sleep health in individual hospital shift workers: A cross sectional telemonitoring study.

BACKGROUND: Telemonitoring of circadian and sleep cycles could identify shift workers at increased risk of poor health, including cancer and cardiovascular diseases, thus supporting personalized prevention. METHODS: The Circadiem cross-sectional study aimed at determining early warning signals of risk of health alteration in hospital nightshifters (NS) versus dayshifters (DS, alternating morning and afternoon shifts). Circadian rhythmicity in activity, sleep, and temperature was telemonitored on work and free days for one week. Participants wore a bluetooth low energy thoracic accelerometry and temperature sensor that was wirelessly connected to a GPRS gateway and a health data hub server. Hidden Markov modelling of activity quantified Rhythm Index, rest quality (probability, p1-1, of remaining at rest), and rest duration. Spectral analyses determined periods in body surface temperature and accelerometry. Parameters were compared and predictors of circadian and sleep disruption were identified by multivariate analyses using information criteria-based model selection. Clusters of individual shift work response profiles were recognized. FINDINGS: Of 140 per-protocol participants (133 females), there were 63 NS and 77 DS. Both groups had similar median rest amount, yet NS had significantly worse median rest-activity Rhythm Index (0·38 [IQR, 0·29-0·47] vs. 0·69 [0·60-0·77], p<0·0001) and rest quality p1-1 (0·94 [0·94-0·95] vs 0·96 [0·94-0·97], p<0·0001) over the whole study week. Only 48% of the NS displayed a circadian period in temperature, as compared to 70% of the DS (p=0·026). Poor p1-1 was associated with nightshift work on both work (p<0·0001) and free days (p=0·0098). The number of years of past night work exposure predicted poor rest-activity Rhythm Index jointly with shift type, age and chronotype on workdays (p= 0·0074), and singly on free days (p=0·0005). INTERPRETATION: A dedicated analysis toolbox of streamed data from a wearable device identified circadian and sleep rhythm markers, that constitute surrogate candidate endpoints of poor health risk in shift-workers. FUNDING: French Agency for Food, Environmental and Occupational Health & Safety (EST-2014/1/064), University of Warwick, Medical Research Council (United Kingdom, MR/M013170), Cancer Research UK(C53561/A19933).

Sleep, Prospective Memory, and Immune Status among People Living with HIV.

Background: Persons living with HIV (PLWH) frequently report sleep complaints, but objective measurements are still lacking regarding sleep continuity, total sleep time per 24 h, and the links with both prospective memory performance and HIV infection parameters. Methods: PLWH (n = 96) and control (n = 96) groups (balanced for gender and age) were monitored by 24h-actigraphy for at least seven consecutive days. The prospective memory performance was assessed through a naturalistic, activity-based task performed twice a day on the actigraph. Results: PLWH had greater sleep latency and worse sleep continuity (higher fragmentation index) for night-time sleep and longest daytime nap (mean duration of the longest nap). Comparable results were reported for the prospective memory task; better performance scores were associated with several sleep parameters in controls but not in PLWH. Finally, within the PLWH group, being a long sleeper per 24 h (total sleep time > 8 h including more and long daytime naps) was associated with a greater severity of the disease (lower CD4 nadir and more frequent history of AIDS-defining events). Conclusions: These findings indicate that PLWH have more fragmented sleep and that the severity of HIV infection is associated with increased sleep duration.

Napping and weekend catchup sleep do not fully compensate for high rates of sleep debt and short sleep at a population level (in a representative nationwide sample of 12,637 adults).

INTRODUCTION: Short total sleep time (TST < 6 h) is a strong major health determinant that correlates with numerous metabolic, cardiovascular and mental comorbidities, as well as accidents. Our aim was to better understand, at a population level, how adults adapt their TST during the week, and how short sleepers and those with sleep debt and sleep restriction use napping or catching up on sleep during weekends (ie, sleep debt compensation by sleeping longer), which may prevent these comorbidities. METHODS: A large representative sample of 12,367 subjects (18-75 years old) responded by phone to questions about sleep on a national recurrent health poll (Health Barometer, Santé Publique France 2017) assessing sleep schedules (TST) at night, when napping, and over the course of a 24-h period while using a sleep log on workdays and weekends. Retained items were: (1) short sleep (TST ≤ 6 h/24 h); (2) chronic insomnia (international classification of sleep disorders third edition, ICSD-3 criteria); (3) sleep debt (self-reported ideal TST - TST > 60 min, severe > 90 min); and (4) sleep restriction (weekend TST - workday TST = 1-2 h, severe > 2 h). RESULTS: Average TST/24 h was 6h42 (± 3 min) on weekdays and 7h26 (± 3 min) during weekends. In addition, 35.9% (± 1.0%) of the subjects were short sleepers, 27.7% (± 1.0%) had sleep debt (18.8% (± 0.9%) severe), and 17.4% (± 0.9%) showed sleep restriction (14.4% (± 0.8%) severe). Moreover, 27.4% (± 0.9%) napped at least once per week on weekdays (average: 8.3 min (± 0.5 min)) and 32.2% (± 1.0%) on weekend days (13.7 min (± 0.7 min)). Of the 24.2% (± 0.9%) of subjects with severe sleep debt (> 90 min), only 18.2% (± 1.6%) balanced their sleep debt by catching up on sleep on weekends (14.9% (± 0.8%) of men and 21.5% (± 0.9%) of women), and 7.4% (± 1.2%) of these subjects balanced their sleep debt by napping (7.8% (± 0.5%) of men and 6.6% (± 0.4%) of women). The remaining 75.8% (± 5.4%) did not do anything to balance their severe sleep debt during the week. DISCUSSION AND CONCLUSIONS: Short sleep, sleep debt, and sleep restriction during weekdays affected about one third of adults in our study group. Napping and weekend catch-up sleep only compensated for severe sleep debt in one in four subjects.

A study on the optimal length of actigraphic recording in narcolepsy type 1.

OBJECTIVE: The aim of the present study was to assess the optimal length of actigraphic recordings in patients with narcolepsy type 1. METHODS: A secondary analysis was carried out with the previously collected data in eleven patients with narcolepsy type 1. Ten of the 11 patients were medicated at the time of actigraphic recording. Each patient originally wore an Actiwatch AW64 actigraph for at least 28 consecutive days. Overall, the patients were analyzed for 308 nights. RESULTS: No significant differences were observed between the mean values of the 7-day and 14-day analyzed sets for the parameters sleep efficiency, fragmentation index, sleep onset latency, wake after sleep onset, and total sleep time. CONCLUSIONS: Our data suggest that 7 days of actigraphic recording could be sufficient for these patients. SIGNIFICANCE: Our results for the optimal length of actigraphic recording could be useful for both physicians and patients.

Daytime Exposure to Blue-Enriched Light Counters the Effects of Sleep Restriction on Cortisol, Testosterone, Alpha-Amylase and Executive Processes.

Sleep debt is becoming a better acknowledged cause of physiological stress and neurobehavioral deficits with major public-health concerns. We investigated whether exposure to blue light during daytime could be an efficient countermeasure to limit sleep restriction's impact on relevant behavioral (stress, sleepiness, sustained attention, and memory performance) and physiological (saliva cortisol, testosterone, and alpha-amylase) markers. Our semi-ecological, crossover, randomized design included 17 young men that underwent two sleep-restricted nights (3 h each) followed or not by blue light exposure (30-min-long sessions at 100 lux repeated four times throughout the day). Behavioral and physiological measurements were performed in the lab but outside these periods the participants kept following their usual routine. After sleep restriction, morning cortisol and testosterone, and afternoon alpha-amylase levels decreased. In parallel, subjective ratings of stress and sleepiness increased while performance on the sustained attention and memory tasks deteriorated. In contrast, after periods of blue light exposure, all these parameters were largely restored to baseline levels, despite an identical sleep restriction procedure, although this restorative effect was reduced for the memory task. Our findings suggest that even short exposure to blue light could trigger persistent beneficial effects throughout the day and could be potentially efficient in real-life settings.

Using actigraphy to assess sleep and wake rhythms of narcolepsy type 1 patients: a comparison with primary insomniacs and healthy controls.

OBJECTIVE/BACKGROUND: It has been shown that actigraphy may have a discriminant function (DS) for the diagnosis of narcolepsy type 1 patients (NT1), based on a combination of nighttime and daytime parameters. Here, we aimed to test those findings using another actigraph model with a different clinical sample as control (ie, primary insomniacs, PI), carrying out a secondary analysis of previously collected data. PATIENTS/METHODS: The study sample consisted of 13 NT1 (nine females; mean age 39.38 ± 11.48), 13 PI (nine females; mean age 38.69 ± 10.72) and 13 Healthy Controls (HC) (nine females; mean age 38 ± 10.77). Participants wore the Actiwatch AW64 (Cambridge Neurotechnology Ltd, Cambridge, UK) around the non-dominant wrist for seven consecutive days. RESULTS: Significant differences between groups were observed with a higher number of episodes of wakefulness (wake bouts, WB) in PI than HC, a higher fragmentation index (FI) in NT1 than HC and PI, a higher duration of the longest nap (LNAP) in NT1 than HC and PI and higher DS in PI and NT1 than HC. A new DS (NDS), with LNAP and FI as independent variables, was proposed; which was higher in NT1 than HC and PI. CONCLUSIONS: The present study confirms that actigraphy discriminates NT1 from HC. However, considering PI, a new discriminant function NDS which takes into account LNAP and FI is better for this actigraph model.

Sleep Disturbance and Total Sleep Time in Persons Living with HIV: A Cross-Sectional Study.

Short and long sleep durations have been associated with inflammation and chronic diseases. To study the association between sleep duration/quality and HIV disease severity, a cross-sectional study was conducted in patients living with HIV (PLWHs) using self-administered questionnaires assessing total sleep time, insomnia (ICSD-3 criteria), and poor sleep quality (PSQI > 5). Multivariable logistic regression identified the factors associated with sleep disorders and with HIV features. 640 Parisian ambulatory PLWHs were included. The prevalence of insomnia was 50 and 68% of patients had a PSQI > 5. Patients with CD4 count < 500 cells/mm3 were more likely to be long sleepers (> 8 h/day) (OR 1.49; 95% CI [1.10-1.99]: p < 0.01), and less likely to be short sleepers (< 6 h/day) (OR 0.69; 95% CI[0.50-0.96]; p = 0.04) or to experience insomnia (OR 0.59; 95% CI[0.40-0.86]; p < 0.01). HIV features were not associated with a PSQI > 5. Thus, insomnia and impaired sleep quality were highly prevalent in well-controlled PLWHs and the severity of HIV infection was associated with long sleep times.

Night work and prostate cancer risk: results from the EPICAP Study.

OBJECTIVE: To investigate the role of night work in prostate cancer based on data from the EPICAP Study. METHODS: EPICAP is a French population-based case-control study including 818 incident prostate cancer cases and 875 frequency-matched controls that have been interviewed face to face on several potential risk factors including lifetime occupational history. Detailed information on work schedules for each job (permanent or rotating night work, duration, total number of nights, length of the shift, number of consecutive nights) as well as sleep duration and chronotype, was gathered. Prostate cancer aggressiveness was assessed by Gleason Score. RESULTS: Night work was not associated with prostate cancer, whatever the aggressiveness of prostate cancer, while we observed an overall increased risk among men with an evening chronotype (OR=1.83, 95% CI 1.05 to 3.19). A long duration of at least 20 years of permanent night work was associated with aggressive prostate cancer (OR=1.76, 95% CI 1.13 to 2.75), even more pronounced in combination with a shift length >10 hours or ≥ 6 consecutive nights (OR=4.64, 95% CI 1.78 to 12.13; OR=2.43, 95% CI 1.32 to 4.47, respectively). CONCLUSION: Overall, ever night work, either permanent or rotating, was not associated to prostate cancer. Nevertheless, our results suggest that a long duration of permanent night work in combination with a long shift length or at least six consecutive nights may be associated with prostate cancer, particularly with aggressive prostate cancer. Further studies are needed to confirm those findings.

Napping: A public health issue. From epidemiological to laboratory studies.

Sleep specialists have proposed measures to counteract the negative short- and long-term consequences of sleep debt, and some have suggested the nap as a potential and powerful "public health tool". Here, we address this countermeasure aspect of napping viewed as an action against sleep deprivation rather than an action associated with poor health. We review the physiological functions that have been associated positively with napping in both public health and clinical settings (sleep-related accidents, work and school, and cardiovascular risk) and in laboratory-based studies with potential public health issues (cognitive performance, stress, immune function and pain sensitivity). We also discuss the circumstances in which napping-depending on several factors, including nap duration, frequency, and age-could be a potential public health tool and a countermeasure for sleep loss in terms of reducing accidents and cardiovascular events and improving sleep-restriction-sensitive working performance. However, the impact of napping and the nature of the sleep stage(s) involved still need to be evaluated, especially from the perspective of coping strategies in populations with chronic sleep debt, such as night and shift workers.

Vascular response to 1 week of sleep restriction in healthy subjects. A metabolic response?

BACKGROUND: Sleep loss may induce endothelial dysfunction, a key factor in cardiovascular risk. We examined the endothelial function during one week of sleep restriction and a recovery period (from 3-to-13 days) in healthy subjects, and its link to autonomic, inflammatory and/or endocrine responses. METHODS: 12 men were followed at baseline (B1, 8-h sleep), after 2 (SR2) and 6 (SR6) days of SR (4-h sleep: 02:00-06:00) and after 1 (R1) and 12 (R12) recovery nights (8h sleep). At 10:00, we assessed changes in: arm cutaneous vascular conductance (CVC) induced by local application of methacholine (MCh), cathodal current (CIV) and heat (44°C), finger CVC and skin temperature (Tfi) during local cold exposure (5°C, 20-min) and passive recovery (22°C, 20-min). Blood samples were collected at 08:00. RESULTS: Compared with baseline (B1), MCh and heat-induced maximal CVC values (CVC peak) were decreased at SR6 and R1. No effect of SR was observed for Tfi and CVC during immersion whereas these values were lower during passive recovery on SR6 and R1. From SR2 to R12, plasma concentrations of insulin, IGF-1 (total and free) and MCP-1 were significantly increased while those of testosterone and prolactin were decreased. Whole-blood blood mRNA concentrations of TNF-α and IL-1ß were higher than B1. No changes in noradrenaline concentrations, heart rate and blood pressure were observed. CONCLUSIONS: These results demonstrate that SR reduces endothelial-dependent vasodilatation and local tolerance to cold. This endothelial dysfunction is independent of blood pressure and sympathetic activity but associated with inflammatory and metabolic pathway responses (ClinicalTrials-NCT01989741).

Napping reverses the salivary interleukin-6 and urinary norepinephrine changes induced by sleep restriction.

CONTEXT: Neuroendocrine and immune stresses imposed by chronic sleep restriction are known to be involved in the harmful cardiovascular effects associated with poor sleep. OBJECTIVES: Despite a well-known beneficial effect of napping on alertness, its effects on neuroendocrine stress and immune responses after sleep restriction are largely unknown. DESIGN: This study was a strictly controlled (sleep-wake status, light environment, caloric intake), crossover, randomized design in continuously polysomnography-monitored subjects. SETTING: The study was conducted in a laboratory-based study. PARTICIPANTS: The subjects were 11 healthy young men. INTERVENTION: We investigated the effects on neuroendocrine and immune biomarkers of a night of sleep restricted to 2 h followed by a day without naps or with 30 minute morning and afternoon naps, both conditions followed by an ad libitum recovery night starting at 20:00. MAIN OUTCOME MEASURES: Salivary interleukin-6 and urinary catecholamines were assessed throughout the daytime study periods. RESULTS: The increase in norepinephrine values seen at the end of the afternoon after the sleep-restricted night was not present when the subjects had the opportunity to take naps. Interleukin-6 changes observed after sleep deprivation were also normalized after napping. During the recovery day in the no-nap condition, there were increased levels of afternoon epinephrine and dopamine, which was not the case in the nap condition. A recovery night after napping was associated with a reduced amount of slow-wave sleep compared to after the no-nap condition. CONCLUSIONS: Our data suggest that napping has stress-releasing and immune effects. Napping could be easily applied in real settings as a countermeasure to the detrimental health consequences of sleep debt.

Napping reverses increased pain sensitivity due to sleep restriction.

STUDY OBJECTIVE: To investigate pain sensitivity after sleep restriction and the restorative effect of napping. DESIGN: A strictly controlled randomized crossover study with continuous polysomnography monitoring was performed. SETTING: Laboratory-based study. PARTICIPANTS: 11 healthy male volunteers. INTERVENTIONS: Volunteers attended two three-day sessions: "sleep restriction" alone and "sleep restriction and nap". Each session involved a baseline night of normal sleep, a night of sleep deprivation and a night of free recovery sleep. Participants were allowed to sleep only from 02:00 to 04:00 during the sleep deprivation night. During the "sleep restriction and nap" session, volunteers took two 30-minute naps, one in the morning and one in the afternoon. MEASUREMENTS AND RESULTS: Quantitative sensory testing was performed with heat, cold and pressure, at 10:00 and 16:00, on three areas: the supraspinatus, lower back and thigh. After sleep restriction, quantitative sensory testing revealed differential changes in pain stimuli thresholds, but not in thermal threshold detection: lower back heat pain threshold decreased, pressure pain threshold increased in the supraspinatus area and no change was observed for the thigh. Napping restored responses to heat pain stimuli in the lower back and to pressure stimuli in the supraspinatus area. CONCLUSIONS: Sleep restriction induces different types of hypersensitivity to pain stimuli in different body areas, consistent with multilevel mechanisms, these changes being reversed by napping. The napping restorative effect on pain thresholds result principally from effects on pain mechanisms, since it was independent of vigilance status.

The risks of sleeping "too much". Survey of a National Representative Sample of 24671 adults (INPES health barometer).

BACKGROUND: A significant U-shaped association between sleep duration and several morbidity (obesity, diabetes or cardiovascular disease) and mortality risks has been regularly reported. However, although the physiological pathways and risks associated with "too short sleep" (<5 hours/day) have been well demonstrated, little is known about "too much sleeping". PURPOSE: To explore socio-demographic characteristics and comorbidities of "long sleepers" (over 10 hours/day) from a nationally representative sample of adults. METHODS: A cross-sectional nationally representative sample of 24,671 subjects from 15 to 85-year-old. An estimated total sleep time (TST) on non-leisure days was calculated based on a specifically designed sleep log which allows to distinguish "long sleepers" from "short sleepers" (<5 hours/day). Insomnia was assessed according to the International classification of sleep disorders (ICSD-2). RESULTS: The average TST was 7 hours and 13 minutes (+/- 17 minutes). Six hundred and twelve subjects were "long sleepers" (2.7%) and 1969 "short sleepers" (7.5%). Compared to the whole group, "long sleepers" were more often female, younger (15-25 year-old) or older (above 65 year-old), with no academic degree, mostly clerks and blue collar workers. "Long sleepers" were significantly more likely to have psychiatric diseases and a greater body mass index (BMI). However, long sleep was not significantly associated with the presence of any other chronic medical disease assessed. Conversely, short sleep duration was significantly associated with almost all the other chronic diseases assessed. CONCLUSIONS: In the general population, sleeping too much was associated with psychiatric diseases and higher BMI, but not with other chronic medical diseases.

Insomnia and accidents: cross-sectional study (EQUINOX) on sleep-related home, work and car accidents in 5293 subjects with insomnia from 10 countries.

The link between sleepiness and the risk of motor vehicle accidents is well known, but little is understood regarding the risk of home, work and car accidents of subjects with insomnia. An international cross-sectional survey was conducted across 10 countries in a population of subjects with sleep disturbances. Primary care physicians administered a questionnaire that included assessment of sociodemographic characteristics, sleep disturbance and accidents (motor vehicle, work and home) related to sleep problems to each subject. Insomnia was defined using the International Classification of Sleep Disorders (ICSD-10) criteria. A total of 5293 subjects were included in the study, of whom 20.9% reported having had at least one home accident within the past 12 months, 10.1% at least one work accident, 9% reported having fallen asleep while driving at least once and 4.1% reported having had at least one car accident related to their sleepiness. All types of accident were reported more commonly by subjects living in urban compared to other residential areas. Car accidents were reported more commonly by employed subjects, whereas home injuries were reported more frequently by the unemployed. Car accidents were reported more frequently by males than by females, whereas home accidents were reported more commonly by females. Patients with insomnia have high rates of home accidents, car accidents and work accidents related to sleep disturbances independently of any adverse effects of hypnotic treatments. Reduced total sleep time may be one factor explaining the high risk of accidents in individuals who complain of insomnia.

Neuroendocrine, immune and oxidative stress in shift workers.

Shift work is commonly associated with disturbed life rhythms, resulting in chronic exposure to circadian desynchronization and sleep restriction. Epidemiological data have shown that shift workers are at an increased risk of cardiovascular disease and breast cancer. In this review, we will explore how observed increases in neuroendocrine stress, non-specific immune responses and pro-oxidative status could act as biological mediators for these damaging health risks in shift workers. To explain these risks, compelling evidence from laboratory studies links circadian misalignment but also sleep restriction to disruptions in the neuroendocrine, immune and oxidative stress systems. Assessment of neuroendocrine, oxidative and immune stress in the shift worker population is still a limited and novel field, which may have considerable clinical relevance. Finally, we will consider the potential benefits of a countermeasure, such as napping, in minimizing the neuroendocrine and immune stress and cardiovascular risk imposed by shift work.

Short sleep duration and increased risk of hypertension: a primary care medicine investigation.

OBJECTIVES: Compelling evidence from laboratory-based and population-based studies link sleep loss to negative cardiovascular health outcomes. However, little is known about the association between sleep duration and hypertension in primary care health settings, independently of other well controlled clinical and biochemical characteristics. We investigated the association between sleep duration and the prevalence of hypertension adjusting for 21 potential confounding factors in a noncontrolled primary care sample. METHODS: The sample included 1046 French adults older than 40 years (mean age, 55.5 years), who visited any of the general practitioners of primary care centers in the Paris area. Blood pressure (BP) readings, blood samples and standardized health and sleep questionnaires were performed on each participant. Hypertension inclusion criteria were either high BP measurements (SBP ≥ 140 mmHg or DBP ≥ 90 mmHg) or the use of antihypertensive medications. Sleep duration was recorded as the self-reported average number of hours of sleep per night during the week. Logistic regressions were performed to test the association between hypertension and sleep duration adjusted for sociodemographic, clinical, biochemical, lifestyle, psychological and sleep disorder covariates. RESULTS: Compared to the group sleeping 7 h, individuals sleeping 5 h or less had an increased odds ratio (OR) for the prevalence of hypertension [OR = 1.80, 95% confidence interval (1.06-3.05)], after adjusting for 21 potential confounders which did not markedly attenuate this association. CONCLUSION: Our data provide further epidemiologic evidence that with no specific selection in primary care medicine, usual short-sleep duration increases the risk of hypertension prevalence in adults over 40 years.