Category Archives: Hours of Work

High-fat diets may be worse for shift workers

Source: Christina Sumners, Futurity, February 6, 2018

Shift workers’ constantly changing schedules make it tough for their biological clocks to keep accurate time. The results could make the negative effects of a high-fat diet even more pronounced, a new study suggests.

About 15 million Americans don’t have a typical nine-to-five workday, and many of them—nurses, firefighters, and flight attendants, among other professions—may see their schedule change drastically one week to the next…..

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Shift work cycle-induced alterations of circadian rhythms potentiate the effects of high fat diet on inflammation and metabolism
Source: Sam-Moon Kim, Nichole Neuendorff, Robert C. Alaniz, Yuxiang Sun, Robert S. Chapkin, and David J. Earnest, Federation of American Societies for Experimental Biology (FASEB) Journal, Published Online: 5 Feb 2018

From the abstract:
Based on genetic models with mutation or deletion of core clock genes, circadian disruption has been implicated in the pathophysiology of metabolic disorders. Thus, we examined whether circadian desynchronization in response to shift work–type schedules is sufficient to compromise metabolic homeostasis and whether inflammatory mediators provide a key link in the mechanism by which alterations of circadian timekeeping contribute to diet-induced metabolic dysregulation. In high-fat diet (HFD)-fed mice, exposure to chronic shifts of the light–dark cycle (12 h advance every 5 d): 1) disrupts photoentrainment of circadian behavior and modulates the period of spleen and macrophage clock gene rhythms; 2) potentiates HFD-induced adipose tissue infiltration and activation of proinflammatory M1 macrophages; 3) amplifies macrophage proinflammatory cytokine expression in adipose tissue and bone marrow–derived macrophages; and 4) exacerbates diet-induced increases in body weight, insulin resistance, and glucose intolerance in the absence of changes in total daily food intake. Thus, complete disruption of circadian rhythmicity or clock gene function as transcription factors is not requisite to the link between circadian and metabolic phenotypes. These findings suggest that macrophage proinflammatory activation and inflammatory signaling are key processes in the physiologic cascade by which dysregulation of circadian rhythmicity exacerbates diet-induced systemic insulin resistance and glucose intolerance.

Examining Exposure Assessment in Shift Work Research: A Study on Depression Among Nurses

Source: Amy L Hall Renée-Louise Franche Mieke Koehoorn, Annals of Work Exposures and Health, Advance Access, January 11, 2018

From the abstract:
Introduction:
Coarse exposure assessment and assignment is a common issue facing epidemiological studies of shift work. Such measures ignore a number of exposure characteristics that may impact on health, increasing the likelihood of biased effect estimates and masked exposure–response relationships. To demonstrate the impacts of exposure assessment precision in shift work research, this study investigated relationships between work schedule and depression in a large survey of Canadian nurses.

Methods:
The Canadian 2005 National Survey of the Work and Health of Nurses provided the analytic sample (n = 11450). Relationships between work schedule and depression were assessed using logistic regression models with high, moderate, and low-precision exposure groupings. The high-precision grouping described shift timing and rotation frequency, the moderate-precision grouping described shift timing, and the low-precision grouping described the presence/absence of shift work. Final model estimates were adjusted for the potential confounding effects of demographic and work variables, and bootstrap weights were used to generate sampling variances that accounted for the survey sample design.

Results:
The high-precision exposure grouping model showed the strongest relationships between work schedule and depression, with increased odds ratios [ORs] for rapidly rotating (OR = 1.51, 95% confidence interval [CI] = 0.91–2.51) and undefined rotating (OR = 1.67, 95% CI = 0.92–3.02) shift workers, and a decreased OR for depression in slow rotating (OR = 0.79, 95% CI = 0.57–1.08) shift workers. For the low- and moderate-precision exposure grouping models, weak relationships were observed for all work schedule categories (OR range 0.95 to 0.99).

Conclusions:
Findings from this study support the need to consider and collect the data required for precise and conceptually driven exposure assessment and assignment in future studies of shift work and health. Further research into the effects of shift rotation frequency on depression is also recommended.

Working 9 to 5? Union Membership and Work Hours and Schedules

Source: Ryan Finnigan Jo Mhairi Hale, Social Forces, Advance Access, Published: January 22, 2018
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From the abstract:
Millions of workers in the United States experience volatile weekly working hours and nonstandard shift work, particularly following the Great Recession. These aspects of work schedules bring greater economic insecurity and work-life conflict, particularly for low-wage workers. In the absence of strong and widespread policies regulating work hours in the United States, labor unions may significantly limit varying hours and nonstandard shifts. However, any benefits of union membership could depend on local unionization rates, which vary widely between states. This paper analyzes the relationship between union membership and varying weekly work hours and nonstandard schedules among hourly workers using data from the 2004–2007 and 2008–2012 Surveys of Income and Program Participation. The results show that union members were significantly less likely to report varying numbers of hours from week to week, particularly in states with relatively high unionization rates. In contrast, union members were more likely to report nonstandard schedules. The earnings penalties for varying hours and nonstandard schedules are significantly weaker among union members than non-members. Altogether, the results demonstrate some of unions’ continued benefits for workers, and some of their limitations.

Precarious schedules linked with workplace aggression in a high-risk occupation

Source: David A. Hurtado, Lisset M. Dumet, Samuel A. Greenspan, Miguel Marino and Kimberly Bernard, American Journal of Industrial Medicine, Early View, November 21, 2017
(subscription required)

From the abstract:
Introduction
Night work and prolonged work hours increase the risk for workplace aggression, however, the risk related to precarious schedules remains unknown.

Methods
Cross-sectional study among Parole Probation Officers (PPOs) (n = 35). A precarious schedules index was created including the following indicators (a) experiencing one or more unexpected shifts during the last 4 weeks; (b) having minimal control over work hours; and (c) shifts notifications of less than a week. Generalized Poisson Regressions estimated the association between precarious schedules and self-reported client-based aggressive incidents (verbal, threating, property, or physical) during the last 12 months.

Results
Workplace aggression was highly prevalent (94.3%). PPOs who experienced precarious schedules (74.3% prevalence) had an adjusted rate of workplace aggression 1.55 times greater than PPOs without precarious schedules (IRR = 1.55, 95% CI 1.25, 1.97, P < 0.001). Conclusions Precarious schedules were associated with workplace aggression. Further research ought to examine whether improving schedule predictability may reduce client-based aggression.

The effect of long working hours on cerebrovascular and cardiovascular disease; A case-crossover study

Source: Kyong-sok Shin, Yun kyung Chung, Young-Jun Kwon, Jun-Seok Son and Se-hoon Lee, American Journal of Industrial Medicine, Vol. 60 Issue 9, September 2017
(subscription required)

From the abstract:
Background:
This study investigated the relationship between weekly working hours and the occurrence of cerebro-cardiovascular diseases using a case-crossover study design.

Methods:
We investigated average working hours during the 7 days before the onset of illness (hazard period) and average weekly working hours between 8 days and 3 months before the onset of cerebro-cardiovascular diseases (control period) for 1,042 cases from the workers’ compensation database for 2009.

Results:
Among all subjects, the odds ratio by conditional logistic regression for the risk of cerebro-cardiovascular diseases with a 10 hr increase in average weekly working hours was 1.45 (95% confidence interval [CI]: 1.22–1.72), a significant association.

Conclusions:
An increase in average weekly working hours may trigger the onset of cerebro-cardiovascular disease.

Long working hours as a risk factor for atrial fibrillation: a multi-cohort study

Source: Mika Kivimäki, Solja T. Nyberg, G. David Batty, Ichiro Kawachi, Markus Jokela, et al, European Heart Journal, July 13, 2017

From the abstract:
Aims:
Studies suggest that people who work long hours are at increased risk of stroke, but the association of long working hours with atrial fibrillation, the most common cardiac arrhythmia and a risk factor for stroke, is unknown. We examined the risk of atrial fibrillation in individuals working long hours (≥55 per week) and those working standard 35–40 h/week.

Methods and results:
In this prospective multi-cohort study from the Individual-Participant-Data Meta-analysis in Working Populations (IPD-Work) Consortium, the study population was 85 494 working men and women (mean age 43.4 years) with no recorded atrial fibrillation. Working hours were assessed at study baseline (1991–2004). Mean follow-up for incident atrial fibrillation was 10 years and cases were defined using data on electrocardiograms, hospital records, drug reimbursement registers, and death certificates. We identified 1061 new cases of atrial fibrillation (10-year cumulative incidence 12.4 per 1000). After adjustment for age, sex and socioeconomic status, individuals working long hours had a 1.4-fold increased risk of atrial fibrillation compared with those working standard hours (hazard ratio = 1.42, 95% CI = 1.13–1.80, P = 0.003). There was no significant heterogeneity between the cohort-specific effect estimates (I2 = 0%, P = 0.66) and the finding remained after excluding participants with coronary heart disease or stroke at baseline or during the follow-up (N = 2006, hazard ratio = 1.36, 95% CI = 1.05–1.76, P = 0.0180). Adjustment for potential confounding factors, such as obesity, risky alcohol use and high blood pressure, had little impact on this association.

Conclusion:
Individuals who worked long hours were more likely to develop atrial fibrillation than those working standard hours.

Employment, Hours, and Earnings Consequences of Job Loss: US Evidence from the Displaced Workers Survey

Source: Henry S. Farber, Journal of Labor Economics 35, no. S1, July 2017
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From the abstract:
Data are used from the 1984–2016 Displaced Workers Surveys (DWS) to investigate the incidence and consequences of job loss, 1981–2015. These data show a record high rate of job loss in the Great Recession, with serious employment consequences for job losers, including very low rates of re-employment and difficulty finding full-time employment. The average reduction in weekly earnings for job losers making a full-time–full-time transition are relatively small, with a substantial minority reporting earning more on their new job than on the lost job. Most of the cost of job loss comes from difficulty finding new full-time employment.

Still falling short on hours and pay: Part-time work becoming new normal

Source: Lonnie Golden, Economic Policy Institute, December 5, 2016

From the summary:
What this report finds: An ongoing structural shift toward more intensive use of part-time employment by many employers is driving the elevated rate of involuntary part-time work. Over six years into an economic recovery, the share of people working part time because they can only get part-time hours remains at recessionary levels. The number working part time involuntarily remains 44.6 percent higher than it was in 2007. This growth is being driven mainly by a few industries.

Why it matters: 6.4 million workers want full-time jobs but are working only part-time hours. Involuntary part-time workers are not only earning less income than they would prefer, but suffer because part-time jobs offer relatively lower wage rates and benefit coverage, and have more variable and unpredictable work schedules.

How we can fix the problem: In addition to traditional expansionary policies that would heighten demand for more hours of labor, here are seven policies that would help curb the excessive use of part-time employment and address the harmful effects of involuntary part-time working.
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