Aline Silva-Costa

Sleep on the job partially compensates for sleep loss in night-shift nurses

Nursing personnel in Brazil are usually submitted to fixed 12 h shifts with no consecutive working days or nights. Moonlighting is common in this group, with a consequent increase in the number of working hours. The possibility of sleeping on the job during the night shift in the studied hospitals had already been described. The present study aims to analyze whether the time devoted to daily activities (sleep, rest, leisure, housework, commuting, personal needs, care of children or other people, non‐paid work, and study) is related to the number of worked hours and to nap‐taking during the night shift. The field study took place at two public hospitals in Rio de Janeiro, Brazil. Workers filled out a structured form on time devoted to the above‐mentioned activities for at least four consecutive days. The time devoted to sleep was analyzed according to its occurrence at home or on the job. Workers were classified according to the number of jobs (one job/two jobs) and the time dedicated to work according to the median of the whole series (below the median/above the median). All workers who had at least one working night were analyzed as to nap‐taking on the job. They were classified according to the sleep occurrence during the night shift—the sleep group and the non‐sleep group, both of which were compared to daytime workers. Statistical treatment of data included non‐parametrical procedures. The study group comprised 144 workers (mean age: 35.7±10.5 years old; 91% women; 78% nurse assistants, the remainder registered nurses). They recorded their daily activities for 4–11 days; 829 cumulative days were analyzed for the whole group. A total of 165 working nights were analyzed; sleep or rest occurred during 112 (68%) of them, with mean sleep/rest duration of 141±86 min. Time devoted to sleep and leisure varied according to the number of working hours, being significantly reduced in those submitted to longer work hours (p<0.001 and p=0.002, respectively). Results close to significance point to a reduction in the time dedicated to housework among workers with long work hours (p=0.053). The time spent on sleep/rest per working night did not differ according to the number of worked hours (p=0.490). A tendency was observed for those who have two jobs to devote more time to sleep/rest on the job (p=0.058). The time of personal needs was significantly lower among those who did not sleep on the job as compared to day workers (p=0.036). The total sleep time was significantly lower among those who did not sleep on the job, as compared to day workers and to those who slept on the job (p=0.004 and p=0.05, respectively). As to home sleep length, workers who slept and those who did not sleep on the job were similar and slept significantly less than exclusively daytime workers (p<0.001 and p=0.002, respectively). Sleeping on the job during the night shift seems to partially compensate for the shorter sleep at home among night workers and may play a beneficial effect in coping with two jobs.

Job Strain and Self-Reported Insomnia Symptoms among Nurses: What about the Influence of Emotional Demands and Social Support?

Job strain, derived from high psychological demands and low job control, is associated with insomnia, but information on the role of emotional demands and social support in this relationship is scarce. The aims of this study were (i) to test the association between job strain and self-reported insomnia symptoms, (ii) to evaluate the combination of emotional demands and job control regarding insomnia symptoms, and (iii) to analyze the influence of social support in these relationships. This cross-sectional study refers to a sample of nurses (N = 3,013 and N = 3,035 for Job Strain and Emotional demand-control model, resp.) working at public hospitals in Rio de Janeiro, Brazil. Data were collected through a self-report questionnaire. The prevalence of insomnia symptoms was 34.3%. Job strain was associated with increased odds for insomnia symptoms (OR: 2.20); the same result was observed with the combination of emotional demands and low job control (OR: 1.99). In both models, the inclusion of low social support combined with high demands and low job control led to increased odds for insomnia symptoms, compared to groups with high social support from coworkers and supervisors. Besides job strain, the study of emotional demands and social support are promising with regards to insomnia symptoms, particularly among nurses.

Need for recovery from work and sleep-related complaints among nursing professionals

The concept of need for recovery from work (NFR) was deduced from the effort recuperation model. In this model work produces costs in terms of effort during the working day. When there is enough time and possibilities to recuperate, a worker will arrive at the next working day with no residual symptoms of previous effort. NFR evaluates work characteristics such as psychosocial demands, professional work hours or schedules. However, sleep may be an important part of the recovery process. The aim of the study was to test the association between sleep-related complaints and NFR. A cross-sectional study was carried out at three hospitals. All females nursing professionals engaged in assistance to patients were invited to participate (N = 1,307). Participants answered a questionnaire that included four sleep-related complaints (insomnia, unsatisfactory sleep, sleepiness during work hours and insufficient sleep), work characteristics and NRF scale. Binomial logistic regression analysis showed that all sleep-related complaints are associated with a high need for recovery from work. Those who reported insufficient sleep showed a greater chance of high need for recovery; OR=2.730 (CI 95% 2.074 - 3.593). These results corroborate the hypothesis that sleep is an important aspect of the recovery process and, therefore, should be thoroughly investigated.

Minor psychiatric disorders among nursing workers – is there an association with current or former night work?

We aimed at analyzing whether Minor Psychiatric Disorders (MPD) is associated to night work either currently or in the past. A cross-sectional study was conducted at three public hospitals in Brazil, with female nursing workers. Data collection (N=1,134) was based on a comprehensive questionnaire that included the self-reported questionnaire (SRQ-20) for screening of MPD. Former night workers were subdivided into three groups according to their reasons for leaving night work: (i) directly related to work, (ii) related to better reconcile with studies or another job, and (iii) related to health, sleep, fatigue or stress. Binomial logistic regression was performed, with adjustment for potential confounders. A dose response gradient was observed between current night work and MPD (OR=1.5; 95% CI: 1.1-2.2 and OR=2.1; 95%CI: 1.5-3.1 for those who worked up to five nights and six or more nights per 2-week span, respectively). Potential detrimental effects of night work were confirmed. The association between working at night and MPD was not restricted to current night workers as workers who left night work for health/fatigue/sleep/strain also showed higher chances of reporting MPD (OR=1.8;95%CI:1.14-2.90). Results contribute to the scientific debate on the impact of night work on health and wellbeing.

Night work is associated with glycemic levels and anthropometric alterations preceding diabetes: Baseline results from ELSA-Brasil.

ABSTRACT Night work has been suggested as a risk factor for diabetes. Individuals with high triglyceride levels, high LDL cholesterol, low HDL cholesterol and obesity, especially abdominal obesity, have a greater chance of developing diabetes. The aim of this study was to analyze glycemic levels, total cholesterol, HDL-C, LDL-C, triglycerides and the anthropometric alterations that precede diabetes, considering their possible association with nigh work among a non-diabetic population. Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) comprises of 15,105 civil servants (35–74 years old) at baseline (2008–2010). The following parameters were analyzed: serum cholesterol (total cholesterol, HDL-C, LDL-C), triglycerides and glucose drawn from 12-hour fasting blood sample, glycated hemoglobin and 2-hour plasma glucose obtained after a 75 g oral glucose tolerance test, BMI, hip and waist measurements using standard equipment and techniques. Participants with diabetes, retired workers and day workers with previous experience of night work were excluded. Generalized linear models, a gamma regression model with an identity link function, were performed to test the association of night work with metabolic and anthropometric variables. The study sample consisted of 3918 men and 4935 women; 305 (7.8%) and 379 (7.7%) of the participants were men and women who worked at night, respectively. Among the men, the exposure to night work was associated with an increase in BMI (b-value = 0.542; p = 0.032) and waist circumference (b-value = 1.66; p = 0.014). For women, increased fasting plasma glucose (b-value = 2.278; p < 0.001), glycated hemoglobin (b-value = 0.099, p < 0.001) and 2 hour plasma glucose (b-value = 5.479, p = 0.001) were associated with night work after adjustments. No significant associations between night work and triglycerides, LDL-C, HDL-C, total cholesterol levels or waist–hip ratio were found. The influences of night work on metabolic and anthropometric factors suggest night work as a potential risk factor for type 2 diabetes. Further studies are needed to investigate the inconclusive data on gender differences in the associations.

Associations of a Short Sleep Duration, Insufficient Sleep, and Insomnia with Self-Rated Health among Nurses

Epidemiological evidence suggests that sleep duration and poor sleep are associated with mortality, as well as with a wide range of negative health outcomes. However, few studies have examined the association between sleep and self-rated health, particularly through the combination of sleep complaints. The objective of this study was to examine whether self-rated health is associated with sleep complaints, considering the combination of sleep duration, insomnia, and sleep sufficiency. This cross-sectional study was performed in the 18 largest public hospitals in the city of Rio de Janeiro, Brazil. A total of 2518 female nurses answered a self-filled multidimensional questionnaire. The adjusted odds ratios and 95% confidence intervals (CIs) estimated the chance of poor self-rated health in the presence of different combinations of sleep duration and quality. Compared with women who reported adequate sleep duration with no sleep quality complaints (reference group), the odds ratios (95% CI) for poor self-rated health were 1.79 (1.27–2.24) for those who reported only insufficient sleep, 1.85 (0.94–3.66) for only a short sleep duration, and 3.12 (1.94–5.01) for only insomnia. Compared with those who expressed all three complaints (short sleep duration, insomnia, and insufficient sleep), the odds ratio for poor self-rated health was 4.49 (3.25–6.22). Differences in the magnitude of the associations were observed, depending on the combination of sleep complaints. Because self-rated health is a consistent predictor of morbidity, these results reinforce the increasing awareness of the role of sleep in health and disease. Our findings contribute to the recognition of sleep as a public health matter that deserves to be better understood and addressed by policymakers.

Gender-specific association between night-work exposure and type-2 diabetes: results from longitudinal study of adult health, ELSA-Brasil

OBJECTIVES Diabetes is a multifactorial disease of increasing prevalence. The literature suggests an impact of night work on metabolic components, though the relationship with diabetes is unclear. Our aim was to investigate gender-specific associations between night work and type-2 diabetes (DM2) or impaired glucose tolerance (IGT) using baseline data of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). METHODS The cohort comprised 15 105 civil servants, aged 35-74 years. Baseline assessments (2008-2010) included clinical and laboratory measurements and interviews on sociodemographic, occupational, and health characteristics. RESULTS In the baseline sample (N=14 427), 19.6% were classified as having DM2 and 20.5% as having IGT. Mean age was 52.1 (SD 9.1) years. A total of 2041 participants worked at night for 1-20 years and 687 for >20 years. Among women exposed to night work for >20 years compared with no night work after adjustments for potential confounders, including obesity, the odds ratios (OR) derived from multinomial logistic regression for DM2 and IGT were 1.42 [95% confidence interval (95% CI) 1.39-1.45] and 0.96 (95% CI 0.94-0.99), respectively. Among men exposed to night work for >20 years compared with no night work, the OR for DM2 and IGT were 1.06 (95% CI 1.04-1.08) and 0.99 (95% CI 0.98-1.01), respectively. CONCLUSIONS The association between years of night work and diabetes is stronger among women than men. Longitudinal studies from ELSA-Brasil will be able to corroborate or refute these findings.

0213 The relationship between night work and mental health among hospital workers

Objectives Night work is suggested as a risk factor for mental health. The objectives of this study were (i) to test the association between the duration of exposure to night work and mental health, evaluated through depression and minor psychiatric disorder (MPD) and (ii) to assess the relationship between intention to leave the night shift and mental health. Method A cross-sectional study was conducted among 432 workers (physical doctors and nursing personnel) at two hospitals in Manaus, Amazonas State, Brazil. Depression condition and MPD were assessed by PHQ-9 and SRQ-20, respectively. The statistical analyses (bivariate, multivariate logistic and multinomial regression) were conducted at SPSS (v.18.0). Results Female workers, those younger than 38 years old, with children under the age of 6 showed higher prevalence of depression and MPD compared to their counterparts. No significant association was detected between time of exposure to night work and mental symptoms. After adjusting for age, sex, education and children’s age, night workers that intended to leave this work schedule showed greater chance of MPD (OR=2.14; 95%IC:1.09–4.23) when compared to those who did not express such a will. Conclusions The time of exposure to night work does not seem to be relevant for the symptoms of mental health here studied. Analysing the intention to leave night work revealed to be an adequate approach to identify workers who are less tolerant to night work, thus possibly detecting those with higher chances of being affected as to their mental health.

Disentangling the effects of insomnia and night work on cardiovascular diseases: a study in nursing professionals

Cardiovascular diseases (CVDs) are known to be associated with poor sleep quality in general populations, but they have not been consistently associated with specific work schedules. Studies of CVD generally do not simultaneously consider sleep and work schedules, but that approach could help to disentangle their effects. We investigated the association between insomnia and a self-reported physician diagnosis of CVD in day and night workers, considering all sleep episodes during nocturnal and diurnal sleep. A cross-sectional study was conducted in 1307 female nursing professionals from 3 public hospitals, using baseline data from the “Health and Work in Nursing - a Cohort Study.” Participants were divided into two groups: i) day workers with no previous experience in night shifts (n=281) and whose data on insomnia were related to nocturnal sleep and ii) those who worked exclusively at night (n=340) and had data on both nocturnal and diurnal sleep episodes, as they often sleep at daytime. Multiple logistic regression analysis was performed. Among day workers, insomnia complaints increased the odds of CVD 2.79-fold (95% CI=1.01-6.71) compared with workers who had no complaints. Among night workers, reports of insomnia during both nocturnal and diurnal sleep increased the odds of reported CVD 3.07-fold (95% CI=1.30-7.24). Workers with insomnia had similar probabilities of reporting CVD regardless of their work schedule, suggesting a relationship to insomnia and not to night work per se. The results also highlighted the importance of including evaluation of all sleep episodes (diurnal plus nocturnal sleep) for night workers.

Work schedule and self-reported hypertension - the potential beneficial role of on-shift naps for night workers.

ABSTRACT Data on the association between shift work and hypertension are controversial. Sleep restriction is hypothesized to be involved in this relationship. Since on-shift nap can partly compensate for sleep deprivation among night workers, this investigation is aimed at (i) comparing the prevalence of hypertension among workers considering both current and former night work, (ii) testing the association between on-shift naps and hypertension among night workers, and (iii) analyzing the influence of sleep complaints in the association between on-shift nap and hypertension. Nap was defined as a sleep episode with duration shorter than the average nighttime sleep. A cross-sectional study was performed at the 18 largest public hospitals in Rio de Janeiro, Brazil, in 2010–2011 (N = 2588 female registered nurses). Nurses were informally allowed to nap for up to three consecutive hours during working nights. Workers completed a multidimensional questionnaire including self-reported information on physician diagnosis of hypertension, napping, and sleep complaints (insomnia, diurnal sleepiness, and non-satisfactory sleep). Epidemiological and statistical treatment of data included binomial logistic regression and interaction tests. Higher chances of hypertension were observed for both current and former night workers compared with workers with no previous experience in night work, i.e. exclusive day workers (OR = 1.68; CI95% 1.22–2.33 and OR = 1.40; CI95% 1.01–1.96, respectively) after adjustment for age, race/ethnicity, physical activity, smoking, alcohol consumption, insomnia, weekly work hours, and BMI. Compared with exclusive day workers, both non-nappers and nappers were at a higher likelihood of reporting hypertension (OR = 1.93 CI95% 1.35–2.79 and OR = 1.41 CI95% 1.08–2.20, respectively). An interaction was observed between napping behavior and insomnia (p = 0.037). In the whole sample of night workers, the lower OR for nappers was confirmed when they were directly compared with non-nappers (OR = 0.76 CI95% 0.59–0.98). Analysis of night workers stratified by insomnia showed a significant reduction in OR for nappers (compared to non-nappers) only among insomniacs (OR = 0.58). Napping during night work may be a protective factor for hypertension, particularly among insomniacs. Factors related to melatonin secretion, blood pressure control, and blood pressure dipping patterns are likely to be involved in the relationship between on-shift napping and blood pressure.