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

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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296 Sex differences in sleep and wakefulness of police officers working shifts: evidence from a field study

SLEEP ◽

10.1093/sleep/zsab072.295 ◽

2021 ◽

Vol 44 (Supplement_2) ◽

pp. A118-A118

Author(s):

Gabriela Caetano ◽

Laura Kervezee ◽

Fernando Gonzales-Aste ◽

Philippe Boudreau ◽

Diane Boivin

Keyword(s):

Sex Differences ◽

Circadian Rhythms ◽

Shift Work ◽

Police Officers ◽

Field Studies ◽

Time Of Day ◽

Cycle Phase ◽

Shift Workers ◽

Work Related ◽

Time Awake

Abstract Introduction National reports of work-related injuries found the excess risk of work injury attributed to shift work to be significantly higher among women. The Working Time Society (WTS) concluded that male sex is one of the few factors that is “consistently associated with perceived or actual shift work tolerance”. However, it is unclear if physiological parameters are involved. Laboratory-controlled studies report sex differences in circadian rhythms (body temperature, melatonin). In sleep deprivation protocols, alertness and cognitive performances were affected by sex, menstrual cycle phase and hormonal contraceptives [HC] use. Nevertheless, field studies that compare male and female shift workers are scarce. Methods An observational study including 76 police officers working on patrol: 56 males and 20 females (11 using [HC], 6 not using [non-HC] and 3 with unknown use of hormonal contraception) aged 32.0 ± 5.3 years. Participants were followed throughout a month-long work cycle (1,457 morning, evening, night, or other shifts, plus rest days). They filled out time-stamped questionnaires (Samn-Perelli, KSS, Visual Analogue Scales, ~5/day; sleep and work-related information, ~1–2/day), completed 5-min Psychomotor Vigilance Tasks (PVT, ~2/day), and wore an actigraph to collect activity data. Linear mixed-effects models were used to analyze the effects of group, time awake and time-of-day on fatigue, sleepiness, alertness, mood and PVT measures. Results Self-reported measures and psychomotor performance significantly varied with time awake and time-of-day. Fatigue and sleepiness levels were significantly higher among female compared to male police officers, both with time awake and across the 24-h day. These variations were similar between non-HC females and the other groups. Compared to males, HC females were more fatigued and less alert, both with time awake and across the 24-h day, and sleepier with time awake. Having children at home did not explain these differences. Conclusion The results of this study expand our knowledge on the sex differences in the sleep and circadian physiology and demonstrate a critical effect of HC on women fatigue, sleepiness and alertness when working shifts. Sex and hormonal parameters must be considered in occupational medicine as well as in future laboratory and field studies on shift workers and circadian rhythms. Support (if any) IRSST, FRQS.

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Ayurveda Internal Medicine for the Management of Common Metabolic Disorders W.S.R. to Madhumeha and Sthoulya

Journal of Drug Delivery and Therapeutics ◽

10.22270/jddt.v9i5-s.3637 ◽

2019 ◽

Vol 9 (5-s) ◽

pp. 167-169

Author(s):

Dhananjay S. Khot

Keyword(s):

Internal Medicine ◽

Metabolic Syndrome ◽

Life Style ◽

Metabolic Disorders ◽

Dietary Habits ◽

Metabolic Diseases ◽

Health Issues ◽

The Metabolic Syndrome ◽

Sedentary Life Style

The metabolic disorders are major health issues of today’s scenario and incidences of metabolic diseases increases day by day due to the disturbed pattern of life style. Ayurveda texts have described term “Santarpanjanya Vikaras” which resembles diseases of defective tissue metabolism. Ayurveda mentioned that improper dietary habits and sedentary life style affects state of Agni which resulted Ama production and finally leading to the metabolic syndrome. The vitiation of Dosha, diminish state of Dhatu and blockage of channels, etc. also can initiate pathogenesis of metabolic disorders. The Kayachikitsa branch of Ayurveda recommended use of internal medicine for the management of various metabolic disorders. Considering increased health burden of society due to the metabolic syndrome present article explore role of ayurveda internal medicine for the management of metabolic syndrome. Keywords: Ayurveda, metabolic syndrome, Santarpanjanya, Madhumeha and Sthoulya.

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Genomic heterogeneity affects the response to Daylight Saving Time

10.1101/2021.03.10.434637 ◽

2021 ◽

Author(s):

Jonathan Tyler ◽

Yu Fang ◽

Cathy Goldstein ◽

Daniel Forger ◽

Srijan Sen ◽

...

Keyword(s):

Circadian Rhythms ◽

Shift Work ◽

Mental Health Problems ◽

Multiple Time ◽

Physical And Mental Health ◽

Daylight Saving Time ◽

Circadian Misalignment ◽

Daylight Saving ◽

The One ◽

External Time

ABSTRACTCircadian rhythms drive the timing of many physiological events in the 24-hour day. When individuals undergo an abrupt external shift (e.g., change in work schedule or travel across multiple time zones), circadian rhythms become misaligned with the new time and may take several days to adjust. Chronic circadian misalignment, e.g., as a result of shift work, has been shown to lead to several physical and mental health problems. Despite the serious health implications of circadian misalignment, relatively little is known about how genetic variation affects an individual’s ability to shift to abrupt external changes. Accordingly, we use the one-hour advance from the onset of daylight saving time (DST) as a natural experiment to comprehensively study how individual heterogeneity affects the shift of sleep-wake rhythms in response to an abrupt external time change. We find that individuals genetically predisposed to a morning tendency adjust to the advance in a few days, while genetically predisposed evening-inclined individuals have not shifted. Observing differential effects by genetic disposition after a one-hour advance underscores the importance of heterogeneity in adaptation to external schedule shifts, and these genetic differences may affect how individuals adjust to jet lag or shift work as well.

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Overweight and obesity in shift workers: associated dietary and lifestyle factors

European Journal of Public Health ◽

10.1093/eurpub/ckaa084 ◽

2020 ◽

Vol 30 (3) ◽

pp. 532-537

Author(s):

Victoria M O’Brien ◽

Fiona M Nea ◽

L Kirsty Pourshahidi ◽

M Barbara E Livingstone ◽

Laura Bardon ◽

...

Keyword(s):

Shift Work ◽

Metabolic Diseases ◽

Cross Sectional Study ◽

Overweight And Obesity ◽

The European Union ◽

Related Factors ◽

Cross Sectional ◽

Shift Workers ◽

Lifestyle Behaviours ◽

Fried Foods

Abstract Background Approximately 17% of the European Union workforce is engaged in shift work. Shift work has been associated with a number of chronic conditions, including obesity and obesity-related metabolic diseases. The aim of this study was to explore the dietary and lifestyle behaviours of shift workers with a healthy vs. overweight/obese body mass index (BMI). Methods A cross-sectional study was conducted on 1080 shift workers using a 15-min, telephone-administered questionnaire developed from qualitative research on Irish shift workers and national dietary intake data. Demographic and work-related factors, as well as dietary and lifestyle behaviours were recorded. BMI was calculated using self-reported height and weight. Univariate and multivariate logistic regression methods were used to analyze data according to BMI category. Results Over 40% of shift workers were classified as overweight or obese. Multivariate analysis indicated that being male [P < 0.001, aOR = 2.102, 95% CI (1.62–2.73)] and middle- or older-aged were independently associated with overweight and obesity [P < 0.001, aOR = 2.44 95% CI (1.84–3.24) and P < 0.001, aOR = 2.9 95% CI (1.94–4.35), respectively]. Having a medium–high consumption of fried foods was independently associated with overweight and obesity [aOR = 1.38, 95% CI (1.06–1.8)]. Conclusions Similar to the general population, overweight and obesity were strongly associated with male sex and middle- or older-age. Male shift workers may benefit from targeted dietary and lifestyle advice specifically focused on limiting fried foods to help protect against overweight and obesity.

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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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Relationship between Sleep and Hedonic Appetite in Shift Workers

Nutrients ◽

10.3390/nu12092835 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2835

Author(s):

Parisa Vidafar ◽

Sean W. Cain ◽

Ari Shechter

Keyword(s):

Weight Gain ◽

Food Intake ◽

Circadian Rhythms ◽

Sleep Quality ◽

Shift Work ◽

Poor Sleep ◽

Shift Workers ◽

Disturbed Sleep ◽

Food Intake Regulation ◽

Intake Regulation

Short and/or poor sleep are established behavioral factors which can contribute to excess food intake, and emerging evidence suggests that disturbed circadian rhythms may also impact food intake regulation. Together, disturbed sleep and circadian rhythms may help explain the excess risk for obesity seen in shift workers. To date, however, the details of how shift work may impact food intake regulation are still not fully defined. Here we examined the relationship between sleep characteristics and hedonic control of appetite in shift workers. A total of 63 shift workers (mean (M) age: 36.7 years, standard deviation (SD): 12.0; 59% women) completed an online survey comprising self-reported measures of body weight regulation, sleep (Pittsburgh Sleep Quality Index, Sleep Hygiene Index), and hedonic control of appetite (Food Craving Inventory, Power of Food Scale). Seventy-one percent reported some weight change since starting shift work, and 84% of those reported weight gain (M = +11.3 kg, SD = 9.1). Worse sleep quality and shorter sleep duration were associated with more food cravings, and worse sleep quality and hygiene were associated with higher appetitive drive to consume palatable food (greater hedonic drive). This preliminary study suggests hedonic pathways are potentially contributing to weight gain in shift workers with disturbed sleep.

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Abstract 14384: Light Therapy Improves Circadian Blood Pressure Control and Glucose Homeostasis in Rotating Night Shift Workers via Mechanisms Independent of Melatonin

Circulation ◽

10.1161/circ.142.suppl_3.14384 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Juliane Hannemann ◽

Anika Laing ◽

Benita Middleton ◽

Jonathan Cridland ◽

Bart Staels ◽

...

Keyword(s):

Blood Pressure ◽

Circadian Rhythms ◽

Glucose Tolerance ◽

Shift Work ◽

Therapy Group ◽

Night Shift ◽

Light Therapy ◽

Pressure Control ◽

Shift Workers ◽

Night Shifts

Introduction: Night shift work is associated with high rates of hypertension, heart disease, and metabolic syndrome. These cardiometabolic diseases have been linked to the disruption of circadian rhythms in night shift workers. Rotating night shift work is increasingly common in the working population worldwide. Hypothesis: We hypothesized that light therapy might help to normalize disrupted circadian rhythms and stabilize diurnal control of blood pressure and glucose tolerance in rotating night shift workers. Methods: We randomized 24 rotating night shift workers (mean age, 36±13 years, 7 males) who had spent a median of 6 years on rotating night shifts with a median of 6 night shifts/month to 12 weeks of light therapy (light during first half of each night shift and in the morning of off-work days) or no intervention and compared them with 12 daytime workers (37±11 years, 6 males). We measured oral glucose tolerance (OGTT), 24h blood pressure and arterial stiffness, and the circadian profiles of melatonin, cortisol, metanephrine and normetanephrine at baseline, after 12 weeks of intervention, and 12 weeks after the end of intervention. Results: At baseline, fewer night shift workers showed dipper status of blood pressure as compared to daytime workers (21% vs. 55%; p<0.001). After 12 weeks of light therapy, there was a highly significant increase in the proportion of dippers (to 42%; p<0.0001). We also observed a significant decrease in serum glucose during OGTT in the light therapy group (-22%; p<0.05), with no change in serum insulin. Whilst circadian profiles of melatonin and cortisol were unchanged, there was a significant reduction in nighttime plasma metanephrine and normetanephrine levels in the light therapy group (p<0.01). Conclusions: Chronotherapeutic light therapy significantly improves diurnal blood pressure control and glucose tolerance in rotating night shift workers. This effect is unrelated to mechanisms traditionally linked to the circadian clock like melatonin and cortisol, but it is paralleled by reduced catecholamine levels. Our data suggest that chronotherapeutic light therapy may improve the adjustment to atypical working hours in rotating night shift workers, thereby reducing stress and improving cardiometabolic function.

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Circadian principles and design of rotating shift work schedules

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1986.251.3.r636 ◽

1986 ◽

Vol 251 (3) ◽

pp. R636-R638 ◽

Cited By ~ 1

Author(s):

F. W. Turek

Keyword(s):

Circadian Rhythms ◽

Shift Work ◽

Sleep Time ◽

New Work ◽

Work Schedules ◽

Work Schedule ◽

Work Time ◽

Shift Workers ◽

Rotating Shift Work ◽

Night Shifts

Circadian rhythms may be disrupted when shift workers rotate from one work schedule to another. It has been suggested that in order to minimize the time needed to readjust circadian rhythms to a new work schedule the work time of shift workers should be rotated in a delaying rather than an advancing direction. However, delaying or advancing the work time does not imply that the sleep-wake cycle is also shifted in a similar manner. Indeed, after a complete rotation between the day, evening, and night shifts the sleep time will be advanced once, delayed once, and not shifted once, regardless of whether the workers are on a delaying or an advancing work rotation schedule. Thus circadian rhythms are likely to be perturbed in a similar manner whether the work schedule is rotated in a delaying or an advancing direction.

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The “ECG modifications induced by the disturbance of the circadian rhythm in night-shift workers (ECGNoct)” study protocol

Romanian Journal of Occupational Medicine ◽

10.2478/rjom-2019-0002 ◽

2019 ◽

Vol 70 (1) ◽

pp. 12-19

Author(s):

Marina Ruxandra Oțelea ◽

Anca Streinu-Cercel ◽

Daniela Manolache ◽

Andreea Mutu ◽

Lavinia Călugăreanu ◽

...

Keyword(s):

Circadian Rhythm ◽

Metabolic Diseases ◽

Clinical Symptoms ◽

Night Shift ◽

Screening Tests ◽

Cross Sectional ◽

Shift Workers ◽

Occupational Risk Factors ◽

The Metabolic Syndrome ◽

Night Shifts

Abstract In many large cohort studies, the night shift constitutes a risk factor for developing cardiovascular disease and diabetes in workers. Current screening tests for people working in night shift include fasting glycaemia and electrocardiography. In fact, there are few studies focused on the description of the electrocardiographic changes after the night shift. This article describes the protocol of the “ECG modifications induced by the disturbance of the circadian rhythm in night-shift workers (ECGNoct)” study, which was initiated by the National Institute for Infectious Diseases “Prof. Dr. Matei Balș”. Nurses represent the target population. The protocol includes a full medical and occupational history, lifestyle habits (smoking, alcohol, nutrition), anthropometric and blood pressure measurements, blood tests (fasting glycemia, total cholesterol, triglycerides and high density lipoprotein cholesterol) and electrocardiogram recording. For nurses working in (night) shifts, we will record the electrocardiogram before and soon after the night shift. A cross sectional study will analyze the incidence of the metabolic syndrome criteria, the cardio-metabolic diseases and the electrocardiographic modifications and will compare the results between the group of nurses working and the group of nurse who do not. Based on these results, a longitudinal study will test the hypothesis that night shift increases the risk for cardio-metabolic diseases and that the electrocardiographic modifications precede the clinical symptoms. The results of the study will provide data on the association of night shifts and other non-occupational risk factors with the cardio-metabolic diseases in this specific population of healthcare workers that potentially will integrate into the occupational medicine policies.

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Adverse effects of shift work at a biscuits manufacturer

10.51415/10321/2588 ◽

2017 ◽

Author(s):

◽

Philisiwe Kenlly Mhlongo

Keyword(s):

Health Outcomes ◽

Shift Work ◽

Work Experience ◽

Night Shift ◽

First Aid ◽

Limited Time ◽

Shift Workers ◽

Domestic Activities ◽

Lost Time ◽

Minor Injuries

Shift work is a necessity for many organizations. Reasons for shift work are mainly to ensure continuous and optimized operations. Many studies on shift workers have concluded that it can lead to adverse physiological, social and psychological health effects. This study examines challenges associated with working shifts at a biscuits manufacturing factory. Results should be able to assist the employer in implementing effective interventions directed at limiting the negative effects of shift work on employees. This is a convergent parallel design multi method stud among 152 shift workers in a biscuits manufacturer located in Durban, KwaZulu Natal. An abbreviated and modified form of the validated SSI questionnaire was used (Barton et al. 1995). The questionnaire contained a battery of items designed to examine the relationship of health and personal adjustment to shift work. Owing to the exploratory nature of the study, a focus group methodology was also used and this allowed for in-depth qualitative research which catered for a more comprehensive understanding of the current shift work issues. A retrospective review of injury records of employees who sustained occupational injuries between 2012 and 2013 was also conducted. The sample comprised of 85 (56%) males and 63 (42%) females. Logistic regression was used to estimate the association between shift work and the likelihood of sleep disturbance, poor health outcomes and limited time for social and domestic activities, adjusting for age, sex, partner working, years working night shift, marital status, job class and years employed. Odds ratio (OR) for reported sleep disturbance was slightly higher among women (OR=1.65; 95% CI = 0.25; 10.84; p < 0.05) compared to males, but this was not statistically significant. Longer shift work experience (i.e.11-20 years) was significantly associated with better health status (OR=0.18; 95%CI = 0.06; 0.46; p < 0.05). Shift work experience (11 to 20 years) was also found to be significantly associated with limited time for both social (OR = 0.10; 95%CI = 0.03; 0.30) and domestic activities (OR= 0.25; 95% CI = 0.11; 0.57; p < 0.05) (Table 4). Age had no effect on social and domestic activities, but those 40 years and above were more likely to have limited time for social and domestic activities (OR = 3.06; 95%CI =0.60; 15.60 and OR= 2.5; 95%CI=0.47; 13.06). Those with more shift work experience seemed to have more time for social and domestic activities compared to those with less than 10 years experience. Findings from the FGD’s revealed that most participants (91%) did not get sufficient sleep time after night shift; this was mainly because of the chores they had to do after getting home form night shift and disturbances from the household and neighbours. The average time spent sleeping by majority of participants after night shift was 5 hours. Swollen feet, gastric, sleep disorders, indigestion and headaches were some common complaints experienced by shift workers in this study. About 27% of participants reported to have been injured at work before. These incidents were reported to be related to drowsiness and fatigue. The company’s incident records showed a total of 160 injuires between 2012 and 2013, of which 38 occurred during night shift. In 2012, the company recorded 65 injuries which included 51 first aid (FA) injuries, 6 minor injuries (MI) and 8 lost time (LT) injuries, as categorized by the company. 2013 had the highest number of incidents, with 95 total injuries, averaging to 7.9 injuries annually. There were 84 first aid incidents recorded for year 2013, 9 minor injuries and only 2 lost time injuries. Twenty three percent (15, n=65) incidents occurred during night shift in year 2012, of which 11% (7, n=65) were females. The number of night shift incidents slightly increased to 24% (23, n=95) in 2013 and females accounted for 9.40%. The records showed that majority of injuries happened between 17h00 and 21h00 at night. Results of this study provides evidence that shift work impacts negatively on the lives of the employees and can lead to adverse health outcomes such as poor dietary intake, headaches and swollen feet to mention but a few.

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