0253 Eating Behaviors, Physical Activity, and Sleep in Shift Workers: Results from a Combined Field and Laboratory Study

Abstract Introduction In shift workers, short sleep duration combined with circadian misalignment may affect behaviors that impact regulation of energy balance and metabolism. We conducted a combined field-and-laboratory study to determine how real-life shift work affects diet, physical activity, and sleep via objective and self-report measures. Methods Participants were day (n=12) and night (n=12) shift workers from an urban hospital setting (nurses and technicians, all female). During the field portion of the study, participants wore a wrist-mounted accelerometer to track sleep and physical activity during their series of shifts, and completed a computer-assisted 24-hour dietary recall. After awakening from the sleep episode following the final work shift, participants entered the laboratory in the fasted state and underwent an ad libitum 14-item test-meal buffet to objectively quantify food choice and intake. Results Sleep duration was significantly shorter and worse quality in night vs. day workers. Physical activity levels were not different between groups. Based on 24-h dietary recall, night vs. day workers consumed less protein (65.9 ± 39.0 vs. 87.2 ± 40.7 g, p=0.01) and fiber (12.5 ± 6.0 vs. 16.9 ± 6.2 g, p=0.01), but did not differ in daily intakes of calories, fat, or carbohydrate. Night vs. day workers reported a longer daily window of eating duration (14.2 ± 3.8 vs. 12.0 ± 1.5 h, p=0.02). In the lab test-meal, there were no group differences in total calories consumed. When expressed as percent of calories consumed, night vs. day workers had lower protein intake (11.82 ± 4.05 vs. 16.03 ± 5.69 %; p=0.05). Conclusion To our knowledge, this was the first study to include a laboratory-based behavioral assessment of food choice/intake in real-life night and day shift workers using objective measures. We did not assess measures of circadian phase so can only assume that circadian misalignment, in addition to the disturbances in sleep duration and quality, contributes to findings. Changes to dietary patterns in night vs. day workers (namely, reduced protein intake which may affect satiety, and prolonged daily eating duration window) may present potential pathways by which night shift work contributes to risk for overweight and obesity. Support UL1TR000040

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Objective Food Intake in Night and Day Shift Workers: A Laboratory Study

Clocks & Sleep ◽

10.3390/clockssleep1010005 ◽

2018 ◽

Vol 1 (1) ◽

pp. 42-49 ◽

Cited By ~ 8

Author(s):

Yichi Chen ◽

Shaza Lauren ◽

Bernard P. Chang ◽

Ari Shechter

Keyword(s):

Food Intake ◽

Sleep Duration ◽

Shift Work ◽

Test Meal ◽

Food Choice ◽

Night Shift ◽

Overweight And Obesity ◽

Shift Workers ◽

Sleep Episode ◽

Night And Day

Night shift work is associated with risk of overweight and obesity. In night shift workers, short sleep duration combined with circadian misalignment may contribute to altered food intake regulation, favoring positive energy balance and weight gain. Prior work investigating food intake in shift workers has suffered methodologically due to reliance on subjective self-report for dietary assessment. No study has yet been done to examine the impact of night shift work on food intake in real-life shift workers using objective measures. Female day (n = 12) and night (n = 12) shift workers from a hospital setting participated in a laboratory-based objective food intake assessment. Participants entered the laboratory in the fasted state after awakening from the sleep episode following a final work shift, and underwent an ad libitum 14-item test meal buffet to objectively quantify food choice/intake. Sleep duration (measured via wrist-accelerometry) during the sleep episode before laboratory assessment was significantly longer in day vs. night workers (373.9 ± 127.5 vs. 260.6 ± 102.9 min, p = 0.03). No significant group difference was observed in calories consumed during the test meal (943.08 ± 469.55 vs. 878.58 ± 442.68 kcal, p = 0.74). When expressed as percent of energy consumed, day workers had higher protein consumption vs. night workers (16.03 ± 5.69 vs. 11.82 ± 4.05%; p = 0.05). To our knowledge, this is the first laboratory-based behavioral assessment of food choice/intake in actual night and day shift workers. Although not studied here, work by others has linked protein intake to satiety. This may be a potential pathway placing shift workers at risk for overweight and obesity.

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0006 The Role of Stress in Sleep in Night Shift Workers: Going Beyond Circadian Misalignment

SLEEP ◽

10.1093/sleep/zsaa056.005 ◽

2020 ◽

Vol 43 (Supplement_1) ◽

pp. A2-A3

Author(s):

E Schaap ◽

C Sagong ◽

A S Cuamatzi Castelan ◽

J Sayed ◽

T Roth ◽

...

Keyword(s):

Sleep Disturbance ◽

Sleep Duration ◽

Shift Work ◽

Night Shift ◽

Sleep Onset ◽

Shift Workers ◽

Circadian Misalignment ◽

Circadian Phase ◽

Falling Asleep ◽

Dim Light

Abstract Introduction Despite a growing need for nighttime work, few studies have characterized the causes of sleep disturbance in night shift workers beyond circadian misalignment. Recent research suggest that high sleep reactivity to stress (a predisposition for sleep disturbance due to stress) may also lead to sleep difficulties in shift workers. This study investigated if sleep reactivity is an independent predictor of daytime sleep disturbances after controlling for circadian phase. Methods Night shift workers (N= 48) completed an 8 hour polysomnography (PSG) during the daytime following a night shift (9am - 4pm). Circadian phase was measured using melatonin assays of saliva samples collected over 24 hours under dim light (<10 lux; Dim Light Melatonin Onset [DLMO]). Sleep reactivity was measured using the Ford Insomnia Response to Stress Test (FIRST). Linear regressions were conducted with PSG sleep parameters as outcome variables: difficulty falling asleep (Sleep Onset Latency [SOL] and Latency to Persistent Sleep [LPS]), difficulty staying asleep (Wake After Sleep Onset [WASO]), and sleep duration (Total Sleep Time [TST]). FIRST was tested as a predictor controlling for DLMO. Results After controlling for circadian phase, higher FIRST scores was associated with more difficulty staying asleep (WASO: t[45]=4.059, p<0.001) and shorter sleep duration (TST: t[45] = -4.403, p<0.0001), but not predictive of difficulty falling asleep (SOL: p>0.05). However, higher FIRST scores did predict a longer latency to persistent sleep (LPS: t[45]=2.272, p<0.05). Conclusion These results suggest that sleep reactivity to stress and circadian misalignment are independent processes that are both associated with disrupted daytime sleep in night shift workers. Given that night shift work can also cause psychosocial stress, treatments focused on circadian misalignment alone may not be sufficient. Our study highlights the need to consider sleep reactivity in the clinical management of shift work disorder. Support Support for this study was provided to PC by NHLBI (K23HL138166).

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Circadian misalignment increases mood vulnerability in simulated shift work

Scientific Reports ◽

10.1038/s41598-020-75245-9 ◽

2020 ◽

Vol 10 (1) ◽

Cited By ~ 1

Author(s):

Sarah L. Chellappa ◽

Christopher J. Morris ◽

Frank A. J. L. Scheer

Keyword(s):

Shift Work ◽

Night Shift ◽

Well Being ◽

Continuous Exposure ◽

Shift Workers ◽

Circadian Misalignment ◽

Alignment Condition ◽

Increased Risk ◽

Mood Effects ◽

Alignment Interaction

Abstract Night shift work can associate with an increased risk for depression. As night workers experience a ‘misalignment’ between their circadian system and daily sleep–wake behaviors, with negative health consequences, we investigated whether exposure to circadian misalignment underpins mood vulnerability in simulated shift work. We performed randomized within-subject crossover laboratory studies in non-shift workers and shift workers. Simulated night shifts were used to induce a misalignment between the endogenous circadian pacemaker and sleep/wake cycles (circadian misalignment), while environmental conditions and food intake were controlled. Circadian misalignment adversely impacted emotional state, such that mood and well-being levels were significantly decreased throughout 4 days of continuous exposure to circadian misalignment in non-shift workers, as compared to when they were under circadian alignment (interaction of “circadian alignment condition” vs. “day”, mood: p < 0.001; well-being: p < 0.001; adjusted p-values). Similarly, in shift workers, mood and well-being levels were significantly reduced throughout days of misalignment, as compared to circadian alignment (interaction of “circadian alignment condition” vs. “day”, mood: p = 0.002; well-being: p = 0.002; adjusted p-values). Our findings indicate that circadian misalignment is an important biological component for mood vulnerability, and that individuals who engage in shift work are susceptible to its deleterious mood effects.

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0007 Daytime Sleep in Night Shift Workers: Quantifying the Role of Circadian Misalignment

SLEEP ◽

10.1093/sleep/zsaa056.006 ◽

2020 ◽

Vol 43 (Supplement_1) ◽

pp. A3-A3

Author(s):

E Mann ◽

C Sagong ◽

A Cuamatzi Castelan ◽

M Singh ◽

T Roth ◽

...

Keyword(s):

Sleep Duration ◽

Sleep Disturbances ◽

Night Shift ◽

Sleep Onset ◽

Sleep Onset Latency ◽

Shift Workers ◽

Circadian Misalignment ◽

Daytime Sleep ◽

Falling Asleep ◽

Dim Light

Abstract Introduction Circadian misalignment is commonly cited as a culprit of daytime sleep disturbances in night shift workers; however, the specific impact and magnitude that circadian misalignment has on daytime sleep has not been well-characterized in larger samples of night shift workers. Methods Participants included fixed-night shift workers (n=52, ages 18–50) who completed an 8-hour daytime polysomnography (PSG) in the lab following a night shift. Measures of sleep disturbances included: difficulty falling asleep (sleep onset latency [SOL], latency to persistent sleep [LPS]), difficulty staying asleep (sleep efficiency [SE], wake after sleep onset [WASO]), and sleep duration (total sleep time [TST]). Melatonin samples were collected hourly for 24 hours under dim light (<10 lux) and used to determine dim light melatonin offset (DLMOff). Circadian misalignment (CM) was calculated as the time difference between bedtime and DLMOff (higher values represented sleeping after DLMOff), and correlated with PSG sleep variables. Results CM was significantly associated with difficulty staying asleep (WASO: r=0.48, p<0.001; SE: r=-0.45, p<0.001), and sleep duration (TST: r=-0.38, p<0.01). Specifically, every 3 hours of CM on average added 19.2 minutes of WASO and reduced TST by 15 minutes. In contrast, CM was not significantly correlated with sleep onset difficulties (SOL: r=-0.27; LPS: r=-0.02). Conclusion These data suggest that circadian misalignment in shift workers may be a better predictor of difficulties staying asleep and sleep duration during the day relative to difficulties falling asleep. Because longer work hours (10–12 hours) are common in night shift worker, it may be that sleep initiation difficulties associated with circadian misalignment is masked by elevated fatigue or an increased homeostatic drive from prolonged wakefulness. These results may help guide decisions about the magnitude of phase shifts required (e.g., with light therapy) for the desired improvement in daytime sleep. Support Support for this study was provided to PC by the NHLBI (K23HL138166)

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Obesity and shift work: chronobiological aspects

Nutrition Research Reviews ◽

10.1017/s0954422410000016 ◽

2010 ◽

Vol 23 (1) ◽

pp. 155-168 ◽

Cited By ~ 230

Author(s):

L. C. Antunes ◽

R. Levandovski ◽

G. Dantas ◽

W. Caumo ◽

M. P. Hidalgo

Keyword(s):

Shift Work ◽

Biological Clock ◽

Overweight And Obesity ◽

Present Review ◽

Epidemiological Evidence ◽

Shift Workers ◽

Circadian Misalignment ◽

Increased Risk ◽

Business Competitiveness ◽

The Impact

The present review has the objective of summarising chronobiological aspects of shift work and obesity. There was a systematic search in PubMed databases, using the following descriptors: shift work; obesity; biological clock. Shift work is extremely frequent in several services and industries, in order to systematise the needs for flexibility of the workforce, necessary to optimise productivity and business competitiveness. In developing countries, this population represents a considerable contingent workforce. Recently, studies showed that overweight and obesity are more prevalent in shift workers than day workers. In addition, the literature shows that shift workers seem to gain weight more often than those workers submitted to a usual work day. In conclusion, there is considerable epidemiological evidence that shift work is associated with increased risk for obesity, diabetes and CVD, perhaps as a result of physiological maladaptation to chronically sleeping and eating at abnormal circadian times. The impact of shift work on metabolism supports a possible pathway to the development of obesity and its co-morbities. The present review demonstrated the adverse cardiometabolic implications of circadian misalignment, as occurs chronically with shift workers.

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The Impact of Shift Work on Diabetes Self-Management Activities

Journal of Doctoral Nursing Practice ◽

10.1891/2380-9418.12.1.66 ◽

2019 ◽

Vol 12 (1) ◽

pp. 66-72

Author(s):

Daniel J. Navarro ◽

Patricia T. Alpert ◽

Chad Cross

Keyword(s):

Physical Activity ◽

Primary Care ◽

Blood Glucose ◽

Shift Work ◽

Diabetes Care ◽

Night Shift ◽

Blood Glucose Control ◽

Self Management ◽

Shift Workers ◽

The Impact

BackgroundOnce a person is diagnosed with diabetes, aggressive management is imperative to minimize poor glycemic control devastating outcomes. However, for some patients reaching optimum blood glucose levels is challenging due to the complexity of diabetes care. To achieve good blood glucose control, patients affected by diabetes must engage in self-care activities that include routine blood glucose check, dietary control, physical activity, medication regimen, and routine medical provider visits. Diabetes-associated self-care activities aimed to reach good blood glucose control can be hindered by multiple factors including shift work.ObjectiveTo evaluate self-management activities of individuals affected by diabetes who are employed as shift workers. This study also informs primary care nurse practitioners of the challenges shift workers face in managing their disease.MethodsThis was a cross-sectional descriptive study. Participants were individuals affected by type II diabetes from a single primary care practice (N = 86); 45 were individuals working on the dayshift and 41 worked on the evening/night shift. Each participant completed the diabetes self-management questionnaire and author-developed demographic/supplemental questionnaire.ConclusionsThere were no differences in self-reported diabetes management activities (i.e., physical activity, glucose management, and healthcare use) between the two groups. Thirty-nine percent of participants working shifts reported worse sleep patterns compared to their dayshift counterparts (X2[1, N = 85] = 8.73, p = .003). Evening/night shift workers also reported more symptoms such as leg pain, fungal infection, numbness of the feet and legs, dizziness, and vision changes (X2[1, N = 79] = 43.037, p < .001).Implications for PracticeA better understanding of the impact that shift work has on diabetes care may help healthcare providers formulate meaningful treatment plans to meet the needs of evening/night shift diabetic workers. The use of a patient-centered medical home is one strategy.

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Social jetlag and sleep debts are altered in different rosters of night shift work

PLoS ONE ◽

10.1371/journal.pone.0262049 ◽

2022 ◽

Vol 17 (1) ◽

pp. e0262049

Author(s):

Swaantje Casjens ◽

Frank Brenscheidt ◽

Anita Tisch ◽

Beate Beermann ◽

Thomas Brüning ◽

...

Keyword(s):

Sleep Quality ◽

Sleep Deprivation ◽

Sleep Duration ◽

Shift Work ◽

Night Shift ◽

Shift Workers ◽

Social Jetlag ◽

Sleep Debt ◽

The Impact ◽

Night Shifts

Background Night and shift work are suspected to cause various adverse effects on health and sleep. Sleep deprivation through shift work is assumed to be compensated on free days. So far it is not clear how different shift systems and shift lengths affect sleep structure on work and free days. Especially working night shifts disrupts the circadian rhythm but also extended working hours (12h) might affect sleep characteristics. Hitherto, the magnitude of sleep debt, social jetlag, and Locomotor Inactivity During Sleep (LIDS) in different shift systems is unknown. Methods Here, we investigated the impact of five different shift rosters on sleep in 129 industrial workers from Germany. Permanent night work with multiple shift systems with and without night shifts and with different shift lengths were compared. Wrist-activity was monitored over 28 days revealing sleep on- and offsets as well as LIDS as proxy for sleep quality. Overall, 3,865 sleep bouts comprising 22,310 hours of sleep were examined. Results The mean daily age-adjusted sleep duration (including naps) was 6:43h and did not differ between shift workers of different rosters. However, sleep duration on workdays was particularly low in rotational shift systems with 12h-shifts (5:00h), while overall sleep debt was highest. Shift workers showed a median absolute social jetlag of 3:03h, which differed considerably between shift types and rosters (p<0.0001). Permanent night workers had the highest social jetlag (5:08h) and latest mid-sleeps on workdays and free days. Sleep quality was reduced in permanent night shift workers compared with shift workers in other rosters and differed between daytime and nighttime sleep. Conclusions Shift work leads to partial sleep deprivation, which particularly affects workers in 12h-shifts and permanent night shifts. Working these shifts resulted in higher sleep debts and larger absolute social jetlag whereas sleep quality was especially reduced in permanent night shift workers compared with shift workers of other rosters.

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The Effects of Shift Work on Cardio-Metabolic Diseases and Eating Patterns

Nutrients ◽

10.3390/nu13114178 ◽

2021 ◽

Vol 13 (11) ◽

pp. 4178

Author(s):

Alexandra Hemmer ◽

Julie Mareschal ◽

Charna Dibner ◽

Jacques A. Pralong ◽

Victor Dorribo ◽

...

Keyword(s):

Circadian Rhythms ◽

Health Outcomes ◽

Shift Work ◽

Metabolic Disorders ◽

Metabolic Diseases ◽

Eating Patterns ◽

Shift Workers ◽

Circadian Misalignment ◽

The Metabolic Syndrome ◽

Physiological Markers

Energy metabolism is tightly linked with circadian rhythms, exposure to ambient light, sleep/wake, fasting/eating, and rest/activity cycles. External factors, such as shift work, lead to a disruption of these rhythms, often called circadian misalignment. Circadian misalignment has an impact on some physiological markers. However, these proxy measurements do not immediately translate into major clinical health outcomes, as shown by later detrimental health effects of shift work and cardio-metabolic disorders. This review focuses on the effects of shift work on circadian rhythms and its implications in cardio-metabolic disorders and eating patterns. Shift work appears to be a risk factor of overweight, obesity, type 2 diabetes, elevated blood pressure, and the metabolic syndrome. However, past studies showed discordant findings regarding the changes of lipid profile and eating patterns. Most studies were either small and short lab studies, or bigger and longer cohort studies, which could not measure health outcomes in a detailed manner. These two designs explain the heterogeneity of shift schedules, occupations, sample size, and methods across studies. Given the burden of non-communicable diseases and the growing concerns about shift workers’ health, novel approaches to study shift work in real contexts are needed and would allow a better understanding of the interlocked risk factors and potential mechanisms involved in the onset of metabolic disorders.

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Effects of irregular-shift work and physical activity on cardiovascular risk factors in truck drivers

Revista de Saúde Pública ◽

10.1590/s0034-8910.2013047004510 ◽

2013 ◽

Vol 47 (3) ◽

pp. 497-505 ◽

Cited By ~ 18

Author(s):

Elaine Cristina Marqueze ◽

Melissa Araújo Ulhôa ◽

Claudia Roberta de Castro Moreno

Keyword(s):

Physical Activity ◽

Risk Factors ◽

Cardiovascular Risk ◽

Cardiovascular Risk Factors ◽

Shift Work ◽

Leisure Time ◽

Leisure Time Physical Activity ◽

Truck Drivers ◽

Shift Workers ◽

Work Demand

OBJECTIVE: To analyze the putative effect of type of shift and its interaction with leisure-time physical activity on cardiovascular risk factors in truck drivers.METHODS: A cross-sectional study was undertaken on 57 male truck drivers working at a transportation company, of whom 31 worked irregular shifts and 26 worked on the day-shift. Participants recorded their physical activity using the International Physical Activity Questionnaire along with measurements of blood pressure, body mass index and waist-hip ratio. Participants also provided a fasting blood sample for analysis of lipid-related outcomes. Data were analyzed using a factorial model which was covariate-controlled for age, smoking, work demand, control at work and social support.RESULTS: Most of the irregular-shift and day-shift workers worked more than 8 hours per day (67.7% and 73.1%, respectively). The mean duration of experience working the irregular schedule was 15.7 years. Day-shift workers had never engaged in irregular-shift work and had been working as a truck driver for 10.8 years on average. The irregular-shift drivers had lower work demand but less control compared to day-shift drivers (p < 0.05). Moderately-active irregular-shift workers had higher systolic and diastolic arterial pressures (143.7 and 93.2 mmHg, respectively) than moderately-active day-shift workers (116 and 73.3 mmHg, respectively) (p < 0.05) as well as higher total cholesterol concentrations (232.1 and 145 mg/dl, respectively) (p = 0.01). Irrespective of their physical activity, irregular-shift drivers had higher total cholesterol and LDL-cholesterol concentrations (211.8 and 135.7 mg/dl, respectively) than day-shift workers (161.9 and 96.7 mg/dl, respectively (ANCOVA, p < 0.05).CONCLUSIONS: Truck drivers are exposed to cardiovascular risk factors due to the characteristics of the job, such as high work demand, long working hours and time in this profession, regardless of shift type or leisure-time physical activity.

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The mediating role of lifestyle in the relationship between shift work, obesity and diabetes

International Archives of Occupational and Environmental Health ◽

10.1007/s00420-021-01662-6 ◽

2021 ◽

Author(s):

Gerben Hulsegge ◽

Karin I. Proper ◽

Bette Loef ◽

Heleen Paagman ◽

Johannes R. Anema ◽

...

Keyword(s):

Physical Activity ◽

Sleep Quality ◽

Shift Work ◽

Activity Levels ◽

Shift Workers ◽

Mediating Role ◽

Obesity And Diabetes ◽

The Relationship ◽

Lower Physical Activity

Abstract Purpose Shift work has been related to obesity and diabetes, but the potential mediating role of lifestyle is yet unknown. Our aim was to investigate this mediating role of physical activity, diet, smoking, and sleep quality in the relationships between shift work, and obesity and diabetes. Methods In this cross-sectional study, 3188 shift workers and 6395 non-shift workers participated between 2013 and 2018 in periodical occupational health checks. Weight and height were objectively measured to calculate obesity (BMI ≥ 30 kg/m2). Diabetes status, physical activity, diet, smoking, and sleep quality were assessed using standardized questionnaires. Structural equation models adjusted for relevant confounders were used to analyze the mediating role of lifestyle in the relationships between shift work, and obesity and diabetes. Results Shift workers were more often obese (OR: 1.37, 95% CI 1.16–1.61) and reported more often to have diabetes (OR:1.35, 95% CI 1.003–1.11) than non-shift workers. Shift workers had lower physical activity levels, ate fruit and vegetables less often, smoked more often, and had poorer sleep quality (p < 0.05). Mediation analysis revealed that shift workers had a higher odds of obesity (OR: 1.07, 95% CI 1.01–1.15) and diabetes (OR: 1.13, 95% CI 1.02–1.27) mediated by poorer sleep quality. Lower physical activity levels (OR: 1.11, 95% CI 1.05–1.19) and lower intake of fruit and vegetables (OR: 1.04, 95% CI 1.01–1.15) were also mediators in the relationship between shift work and obesity, but not in the relationship between shift work and diabetes (p ≥ 0.05). Conclusion These results imply that interventions targeting diet, physical activity and in particular sleep problems specifically developed for shift workers could potentially reduce the adverse health effects of shift work.

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