Metabolic Responses on the Early Shift

Abstract

Shiftwork has been associated with a higher propensity for the development of metabolic disorders and obesity. The aim of the study was to investigate concentrations of glucose, cortisol, and insulin among fixed night workers (n = 9), fixed early morning workers (n = 6), and day workers (n = 7). Food intake was recorded for 7 days using a diary. Blood samples were collected every 4 h over the course of 24 h, yielding six samples. Total carbohydrate intake was lowest (p < .0005), whereas fat (p = .03) and protein (p < .0005) were highest on the early morning shifts. Early morning workers also had overall elevated cortisol levels relative to the other two groups. Cortisol levels appeared to be more influenced by time since waking prior to the shift than by time-of-day. Cortisol was highest for the early morning group than the day group 12 h after waking, and both the early morning and night groups had higher levels than the day group 16 h after waking (p < .05 in all cases). In contrast, the homesostatsis model assessment of insulin resistance (HOMA-IR) appeared to be more influenced by time-of-day than by time since waking prior to the shift. The early morning group had higher levels of HOMA-IR at 08:00 h than the other groups (p < .05). In conclusion, the early morning group had the highest overall concentrations of cortisol and tended to have higher levels of HOMA-IR, indicating that more attention should be given to these workers. Moreover, all three groups showed pronounced cortisol levels on awakening, suggesting that they may have adjusted to their awaking time. (Author: heloguarita@rgnutri.com.br ).

Oxidative stress and insulin resistance in policemen working shifts

“…HOMA-IR provides comparable assessment of insulin resistance to other validated methods, and there are evidences regarding association between problems insulin resistance and shift work in the literature (Parent-Thirion et al 2007;Lauren et al 2012). Padilha et al (2010) investigated the concentrations of glucose, cortisol and insulin among fixed night workers, fixed early morning workers and day workers. In above study, blood samples were taken every 4 h at work, and they found that fixed early morning workers had higher levels of HOMA-IR at 08:00 h than the other groups.…”

Energy intake of shift workers compared to fixed day workers: A systematic review and meta-analysis

“…Four studies investigated rotating shift workers (Esquirol et al, 2009;Morikawa et al, 2008;Romon et al, 1992;Yoshizaki et al, 2013) and eight investigated fixed night shift workers (De Assis et al, 2003;Lasfargues et al, 1996;Lennernas et al, 1994;Padilha et al, 2010;Pasqua & Moreno, 2004;Schiavo-Cardozo et al, 2013;Tada et al, 2014;Wirth et al, 2014). The rotating shift schedules differed between studies, with some rotating on a weekly basis and others rotating more frequently.…”

“…The dietary outcomes, energy and macronutrient intake data (where reported), were also extracted as was body mass index (BMI) to allow for comparison between day and shift workers. Data missing from the included studies such as reported EI data (Knutson et al, 1990;Reinberg et al, 1979), macronutrient intakes (Padilha et al, 2010) or shift schedule (Tada et al, 2014;Wirth et al, 2014;Yoshizaki et al, 2013) were requested from authors or extracted from figures (Padilha et al, 2010). Studies where EI data were collected but not reported were excluded once authors had been contacted on two separate occasions (Knutson et al, 1990;Reinberg et al, 1979).…”

“…The occupations of the workers included factory and industrial plant workers (Esquirol et al, 2009;Lennernas et al, 1994;Morikawa et al, 2008;Padilha et al, 2010;Romon et al, 1992), nurses and those working in aged care (Tada et al, 2014;Yoshizaki et al, 2013) with the remainder from various fields of work including professional cleaning (De Assis et al, 2003;Schiavo-Cardozo et al, 2013) and maintenance (Pasqua & Moreno, 2004) Two studies were from unspecified occupations (Lasfargues et al, 1996;Wirth et al, 2014), although the study by Wirth et al (2014) delineated participants into military or non-military. The majority of studies investigated males only (De Assis et al, 2003;Esquirol et al, 2009;Lennernas et al, 1994;Morikawa et al, 2008;Padilha et al, 2010;Pasqua & Moreno, 2004;Romon et al, 1992;Yoshizaki et al, 2013) with the sample size of included studies ranging from 7 participants to 1579 participants for shift workers and 6 participants to 6412 participants for day workers. Length of time participating in shift work was inconsistently reported.…”

Relationship between Food Intake and Sleep Pattern in Healthy Individuals

“…30,31 These disorders probably occur because sleep plays an important role in the metabolic control of the body. 10,11 Therefore, alterations in the quantity and quality of sleep lead to hormonal disturbances; these might be capable of altering the physiological homeostasis and consequently generate diseases.…”