Night shift work, short sleep and obesity

The predictive capability of several anthropometric indices for identifying the risk of metabolic syndrome and its components among industrial workers

Metabolic syndrome (MetS) is closely associated with adverse cardiometabolic outcomes. The objective of this study was to identify practical methods that could enable the effective identification of MetS based on anthropometric indices. The basis of our study involved retrospective database obtained from routine medical prophylactic examinations. This was a cross-sectional study on the health status of male workers employed in hazardous working conditions at industrial enterprises in the Ural region conducted in 2019. A total of 347 male workers employed under hazardous working conditions were investigated. The presence of MetS was established by a healthcare professional in accordance with the guidelines of the International Diabetes Federation (IDF). Simple linear regression was used to evaluate the associations between anthropometric indices and MetS incidence. Logistic regression was used to determine the odds ratios of MetS in relation to increases in anthropometric indices. ROC curves were calculated to compare the ability of each anthropometric index to predict MetS and to determine the diagnostic thresholds of the indicators considered. According to the IDF criteria, 36.3% of the workers had MetS. A direct relationship was found between the individual components of MetS and the anthropometric indices studied. The highest OR was shown by the Body Roundness Index (BRI) of 2.235 (95% CI 1.796-2.781). For different age quartiles, the optimal cut-off values for predicting MetS were as follows: BRI, 4.1-4.4 r.u.; body shape index (ABSI), 0.080-0.083 m11/6 kg-2/3; and lipid accumulation product (LAP), 49.7-70.5 cm mmol/l. The most significant associations with MetS were observed where the values were greater than these cut-off points (Se = 97.4%). The results of this study demonstrated the rapid use of new anthropometric indicators, which have shown good predictive ability and are quite easy to use.

Design of overnight radiology shifts - primum non nocere

Overnight radiology (ONR) is necessary for providing timely patient care but poses unique professional and personal challenges to the radiologists. Maintaining a sustainable, long-term overnight radiology program hinges on the retention of radiologists who grasp the institutional workflow and can adeptly navigate inherent disruptions while consistently delivering high-quality patient care. Design of radiology shifts can significantly impact the performance and well-being of radiologists, with downstream implications for patient care and risk management. We provide a narrative review of literature to make recommendations for optimally designing ONR shifts, with a focus on professional and personal challenges pertinent to overnight radiologists and system-based risk mitigation strategies.

Insomnia, Short Sleep, and Their Treatments: Review of Their Associations with Weight

PURPOSE OF REVIEW

Insomnia and short sleep have been linked with weight gain and obesity. However, these findings have not been consistent across studies. We review recent evidence for the association between insomnia, short sleep, and weight gain, as well as the relationship between behavioral and pharmacological treatments for sleep and weight.

RECENT FINDINGS

The relationship between insomnia and obesity is mixed, with stronger associations between insomnia with short sleep and obesity than other presentations of insomnia. Short sleep is associated with weight gain. Z-drugs and benzodiazapines do not appear to impact weight, but many antidepressants and antipsychotics that are used for insomnia treatment do cause weight gain. The relationships between insomnia and short sleep with weight gain and obesity are inconsistent. More prospective trials are needed to identify mediators and moderators of this relationship to better develop and deliver effective interventions for both sleep and weight problems.

Association between night work and prostate cancer: a systematic review and meta-analysis

OBJECTIVE

The aim was to conduct a systematic review and meta-analysis to study the association between night work and the development of prostate cancer.

METHODS

A systematic literature search was conducted in CINAHL, Embase, MEDLINE, and Web of Science. Studies were included based on a PECOS; the population included men in/above the working age, exposure defined as night work, outcome defined as prostate cancer, and study design restricted to cohort studies. The exclusion of articles, risk-of-bias assessment, and data extraction were performed by two reviewers. A meta-analysis was conducted using a random-effects model, including a sensitivity analysis stratified based on the risk-of-bias assessment. We evaluated publication bias using a funnel plot and Egger´s test, and the level of evidence was assessed using GRADE.

RESULTS

A total of 528 articles were identified, and eight cohort studies were included. Three studies had a moderate risk of bias, while five studies had a high risk of bias. The meta-analysis showed a pooled hazard ratio (HR) of 1.0 (95% CI 0.6-1.7). In the sensitivity analysis, moderate vs. high risk-of-bias studies showed a pooled HR of 1.2 (95% CI 0.3-4.1) and 0.9 (95% CI 0.6-1.3), respectively. Based on GRADE, the level of evidence was rated low.

CONCLUSION

We found no association between night work and the development of prostate cancer. The evidence was assessed as limited and inconsistent. Future studies encompassing consistent definitions of night work, including objective exposure data, are highly warranted.

Rotating shift work time is directly associated with excess body adiposity

OBJECTIVE

To analyze the association between changes in body adiposity and length of service on a schedule of rotating shifts.

METHODS

The study was a cross-sectional investigation conducted during the years 2012, 2015, and 2018, involving individuals engaged in rotating shifts at a company involved in iron ore extraction situated within the Iron Quadrangle region of Minas Gerais and the southeastern region of Pará, Brazil. Sociodemographic and behavioral data were collected along with anthropometric parameters in order to calculate body mass index (BMI) and the waist-to-height ratio (WHtR). For data analysis, a multivariate logistic regression was employed to explore potential associations between indicators of body adiposity and the duration of shift work, employing a hierarchical determination model.

RESULTS

The findings showed that in the multivariate model, controlling for confounding factors, workers with 5 to 10, 10 to 15, and more than 15 years of shift work had 41 to 96% greater odds of being overweight (BMI > 25.0 kg/m2), 71 to 82% of having altered neck circumference (> 40 cm), 33 to 120% of altered WC (>102 cm), and 57 to 214% of having altered WHtR (> 0.5 cm).

CONCLUSION

The findings suggest that time spent in work has a significant effect on anthropometric indicators of body adiposity, especially if the worker has a previously established comorbidity such as dyslipidemia or hypertension and is frequently exposed to night work.

Investigation of obesity and its related factors among Chinese medical staff: a cross-sectional pilot study

BACKGROUND

Many studies have covered the prevalence of obesity in different populations. However, studies on the prevalence and predictors of obesity among medical staff are lacking. The aim of our study is to investigate the prevalence of obesity among medical staff and to identify the related predictors.

METHODS

Using a snowballing recruitment strategy in the form of an electronic questionnaire, a cross-sectional survey was conducted among 1201 medical staff from cooperative hospitals between January and March 2022. We designed a questionnaire to investigate the participants' demographic, lifestyle, diet, physical activity, and work status.

RESULTS

The overall prevalence of obesity was 8.5%, with males (13.7%) having a greater incidence than females (5.7%) (p < 0.001). Multiple logistic regression analyses showed that alcohol drinking (OR, 2.34; 95% CI 1.23-4.42, p = 0.01), sugar-sweetened beverages consumed > 3/week (OR, 2.50; 95% CI 1.02-6.15, p = 0.046), and working a night shift > 1/week (OR, 2.17; 95% CI 1.02-4.61, p = 0.043) were independent predictive factors for obesity in men. For women, having midnight snack having midnight snack (OR, 2.93;95% CI 1.24-6.96, p = 0.015), good sleep quality (OR, 4.47; 95% CI 1.10-21.70, p = 0.038), and working a night shift > 1/week (OR, 3.62; 95% CI 1.73-7.57, p = 0.001) were independently associated with obesity.

CONCLUSIONS

Obesity presented a low prevalence among medical staff. Alcohol drinking, drinking sugar-sweetened beverages > 3/week, and night shift > 1/week predicted a higher risk of obesity in males. In females, having midnight snack, good sleep quality, and night shift > 1/week were independently associated with obesity.

LEVEL OF EVIDENCE

V, descriptive study.

Fasting diets: what are the impacts on eating behaviors, sleep, mood, and well-being?

Fasting diets (FDs) have drawn great attention concerning their contribution to health and disease over the last decade. Despite considerable interest in FDs, the effect of fasting diets on eating behaviors, sleep, and mood-essential components of diet satisfaction and mental health- has not been addressed comprehensively. Understanding the critical role that fasting plays in these elements will open up potential treatment avenues that have not yet been explored. The aim of the present paper was to conduct a comprehensive critical review exploring the effects of fasting on eating behaviors, sleep, and mood. There is currently a lack of clarity regarding which fasting option yields the most advantageous effects, and there is also a scarcity of consistent trials that assess the effects of FDs in a comparable manner. Similarly, the effects and/or treatment options for utilizing FDs to modify eating and sleep behaviors and enhance mood are still poorly understood. Further researches aiming at understanding the impacts of various fasting regimes, providing new insights into the gut-brain axis and offering new treatment avenues for those with resistant anxiety and depression, are warranted. Alteration of eating behaviors can have lasting effects on various physiological parameters. The use of fasting cures can underpin ancient knowledge with scientific evidence to form a new approach to the prevention and treatment of problems associated with co-morbidities or challenges pertaining to eating behaviors. Therefore, a thorough examination of the various fasting regimens and how they impact disease patterns is also warranted.

Chronic blue light-emitting diode exposure harvests gut dysbiosis related to cholesterol dysregulation

Night shift workers have been associated with circadian dysregulation and metabolic disorders, which are tightly coevolved with gut microbiota. The chronic impacts of light-emitting diode (LED) lighting at night on gut microbiota and serum lipids were investigated. Male C57BL/6 mice were exposed to blue or white LED lighting at Zeitgeber time 13.5-14 (ZT; ZT0 is the onset of "lights on" and ZT12 is the "lights off" onset under 12-hour light, 12-hour dark schedule). After 33 weeks, only the high irradiance (7.2 J/cm2) of blue LED light reduced the alpha diversity of gut microbiota. The high irradiance of white LED light and the low irradiance (3.6 J/cm2) of both lights did not change microbial alpha diversity. However, the low irradiance, but not the high one, of both blue and white LED illuminations significantly increased serum total cholesterol (TCHO), but not triglyceride (TG). There was no significant difference of microbial abundance between two lights. The ratio of beneficial to harmful bacteria decreased at a low irradiance but increased at a high irradiance of blue light. Notably, this ratio was negatively correlated with serum TCHO but positively correlated with bile acid biosynthesis pathway. Therefore, chronic blue LED lighting at a high irradiance may harvest gut dysbiosis in association with decreased alpha diversity and the ratio of beneficial to harmful bacteria to specifically dysregulates TCHO metabolism in mice. Night shift workers are recommended to be avoid of blue LED lighting for a long and lasting time.

Chronic Venous Insufficiency in A Selected Nurse Population: A Cross-Sectional Study

Chronic venous insufficiency (CVI) causes severe symptoms and complications in the general population, but the prevalence, related risk factors, and treatment of CVI are unknown among nurses. The demographics and occupational factors of nurses from a university hospital were collected by questionnaires, and the presentation of CVI was confirmed by the specialist vascular surgeons. A total of 1606 participants were enrolled, and the prevalence of CVI was 7.5%. After multivariate adjustment, CVI was positively related to deep venous thrombosis history (OR 6.44, 95% CI 2.73-15.22), increased standing time (OR 2.21, 95% CI 1.20-4.10), and increased time in night shift rotation (OR 2.01, 95% CI 1.29-3.14). CVI was negatively related to oral contraceptives (OR .43, 95% CI .21-.87). Of the participants, 72.5% with CVI received compression therapy. For them, wearing compression stockings with a pressure of >20 mmHg or for >4 h/day significantly increased the rate of symptom relief, while the length of compression stockings made no difference. Thus, it was beneficial for nurses to spend less time standing and shorten their time in night shift rotation. Wearing compression stockings with sufficient pressure and for enough time was recommended for CVI symptom relief.

Recovery from shift work

One fifth of today's workforce is engaged in shift work and exposed to various mental and physical health risks including shift work disorder. Efficiently recovering from shift work through physical and mental interventions allows us to mitigate negative effects on health, enables a better work-life balance and enhances our overall wellbeing. The aim of this review is to provide a state-of-the-art overview of the available literature. The role of sleep timing and naps, light therapy and psychotherapy, diet and exercise in recovery from shift work is presented here. We further review the impact of shift schedules and social support on post-shift unwinding.

The unfixed light pattern contributes to depressive-like behaviors in male mice

Light pollution is now associated with an increased incidence of mental disorders in humans, and the unfixed light pattern (ULP) is a common light pollution that occurs in such as rotating shift work. However, how much contribution the ULP has to depression and its potential mechanism are yet unknown. Our study aimed to investigate the effect of the ULP on depressive-like behaviors in mice and to explore the links to the circadian-orexinergic system. Male C57BL/6 J mice were exposed to the ULP by subjecting them to an alternating light pattern every 6 days for 54 days. The tail suspension test (TST) and forced swimming test (FST) were conducted to assess depressive-like behaviors. The rhythm of locomotor activity and the circadian expression of cFOS in the suprachiasmatic nucleus (SCN), clock genes in the liver, and corticosterone (CORT) in serum were detected to observe changes in the circadian system. The circadian expression of orexin-A (OX-A) in the lateral hypothalamus area (LHA) and dorsal raphe nucleus (DRN) and serotonin (5-HT) in the DRN were measured to determine alterations in the orexinergic system. The results showed that mice exposed to the ULP exhibited increased immobility time in the TST and FST. The ULP significantly disrupted the circadian rhythm of locomotor activity, clock genes in the liver, and CORT in the serum. Importantly, when exposed to the ULP, cFOS expression in the SCN showed decreased amplitude. Its projection area, the LHA, had a lower mesor of OX-A expression. OX-A projection to the DRN and 5-HT expression in the DRN were reduced in mesor. Our research suggests that the ULP contributes to depressive-like behaviors in mice, which might be related to the reduced amplitude of circadian oscillation in the SCN and hypoactivity of the orexinergic system. These findings may provide novel insights into rotating shift work-related depression.

The Complex Effects of Light on Metabolism in Humans

Light is an essential part of many life forms. The natural light–dark cycle has been the dominant stimulus for circadian rhythms throughout human evolution. Artificial light has restructured human activity and provided opportunities to extend the day without reliance on natural day–night cycles. The increase in light exposure at unwanted times or a reduced dynamic range of light between the daytime and nighttime has introduced negative consequences for human health. Light exposure is closely linked to sleep–wake regulation, activity and eating patterns, body temperature, and energy metabolism. Disruptions to these areas due to light are linked to metabolic abnormalities such as an increased risk of obesity and diabetes. Research has revealed that various properties of light influence metabolism. This review will highlight the complex role of light in human physiology, with a specific emphasis on metabolic regulation from the perspective of four main properties of light (intensity, duration, timing of exposure, and wavelength). We also discuss the potential influence of the key circadian hormone melatonin on sleep and metabolic physiology. We explore the relationship between light and metabolism through circadian physiology in various populations to understand the optimal use of light to mitigate short and long-term health consequences.

Blunted Rest-Activity Circadian Rhythm Is Associated With Increased Rate of Biological Aging: An Analysis of NHANES 2011-2014

Impaired rest-activity circadian rhythm has been associated with increased risk for morbidity and mortality. Animals with mutations in clock genes display accelerated aging and shortened life span. Whether impaired rest-activity circadian rhythm is also associated with processes of aging in humans has not been explored. We analyzed accelerometry and physiological data from 7 539 adults participating in the 2011-2014 waves of the U.S. National Health and Nutrition Examination Surveys. We used accelerometry data to compute rest-activity rhythm measurements. We used physiological data to compute measurements of biological aging according to 3 published algorithms: Klemera-Doubal method (KDM) Biological Age, PhenoAge, and homeostatic dysregulation (HD). In the models adjusting multiple covariates, participants with higher relative amplitude (RA) and interdaily stability (IS) and lower intradaily variability (IV) exhibited less advanced biological aging indexed by KDM and PhenoAge (effect sizes for 1-quantile increase in these rest-activity measurements ranged from 0.54 to 0.57 "years" for RA, 0.24 to 0.28 "years" for IS, and 0.24 to 0.35 "years" for IV, ps < .001). Similar finding was observed for biological aging indexed by HD, but the significance was limited to RA with 1-quantile increase in RA associated with 0.09 log units decrease in HD (p < .001). The results indicate that blunted rest-activity circadian rhythm is associated with accelerated aging in the general population, suggesting that interventions aiming at enhancing circadian rhythm may be a novel approach for the extension of a healthy life span.

Circadian Rhythms Disrupted by Light at Night and Mistimed Food Intake Alter Hormonal Rhythms and Metabolism

Availability of artificial light and light-emitting devices have altered human temporal life, allowing 24-hour healthcare, commerce and production, and expanding social life around the clock. However, physiology and behavior that evolved in the context of 24 h solar days are frequently perturbed by exposure to artificial light at night. This is particularly salient in the context of circadian rhythms, the result of endogenous biological clocks with a rhythm of ~24 h. Circadian rhythms govern the temporal features of physiology and behavior, and are set to precisely 24 h primarily by exposure to light during the solar day, though other factors, such as the timing of meals, can also affect circadian rhythms. Circadian rhythms are significantly affected by night shift work because of exposure to nocturnal light, electronic devices, and shifts in the timing of meals. Night shift workers are at increased risk for metabolic disorder, as well as several types of cancer. Others who are exposed to artificial light at night or late mealtimes also show disrupted circadian rhythms and increased metabolic and cardiac disorders. It is imperative to understand how disrupted circadian rhythms alter metabolic function to develop strategies to mitigate their negative effects. In this review, we provide an introduction to circadian rhythms, physiological regulation of homeostasis by the suprachiasmatic nucleus (SCN), and SCN-mediated hormones that display circadian rhythms, including melatonin and glucocorticoids. Next, we discuss circadian-gated physiological processes including sleep and food intake, followed by types of disrupted circadian rhythms and how modern lighting disrupts molecular clock rhythms. Lastly, we identify how disruptions to hormones and metabolism can increase susceptibility to metabolic syndrome and risk for cardiovascular diseases, and discuss various strategies to mitigate the harmful consequences associated with disrupted circadian rhythms on human health.

The association between daytime sleep and general obesity risk differs by sleep duration in Iranian adults

BACKGROUND

Sleep duration and daytime napping and obesity are related to adiposity; however, it is not clear whether the association between daytime napping and adiposity measures can differ by sleep duration.

AIM

To clarify the association between daytime napping and general and abdominal obesity based on sleep duration of participants.

SUBJECTS AND METHODS

This cross-sectional study was conducted on 1,683 individuals (837 men and 846 women) aged ≥ 35 years. Height, weight and waist circumference (WC) were measured according to the standard protocols. Body mass index (BMI) was calculated. Self-reported sleep duration (in a 24-hour cycle) was recorded. The odds of general and abdominal obesity were compared between nappers and non-nappers, stratified by their sleep duration (≤ 6 h, 6-8 h, ≥ 8 h).

RESULTS

The mean (SD) age of participants was 47.48 ± 9.35 years. Nappers with a short sleep duration (≤ 6 h) had greater BMI and higher risk for overweight/obesity compared with counterpart non-nappers after adjustment for potential confounders (OR = 1.61, 95% CI = 1.07-2.41). In subjects with moderate sleep duration (6-8 h), nappers had a tendency towards higher BMI in comparison with non-nappers (28.04 ± 0.25 vs. 26.93 ± 0.51 kg/m²; p = 0.05), however, no significant difference was observed for the risk of obesity. Daytime napping was not related to the risk of obesity in long sleepers. No significant association was observed for abdominal obesity measures.

CONCLUSIONS

Daytime napping is associated with increased risk of overweight/obesity in short sleepers. However, in subjects with longer sleep duration, it is not related to the risk of overweight/obesity.

Chrononutrition-When We Eat Is of the Essence in Tackling Obesity

Obesity is a chronic and relapsing public health problem with an extensive list of associated comorbidities. The worldwide prevalence of obesity has nearly tripled over the last five decades and continues to pose a serious threat to wider society and the wellbeing of future generations. The pathogenesis of obesity is complex but diet plays a key role in the onset and progression of the disease. The human diet has changed drastically across the globe, with an estimate that approximately 72% of the calories consumed today come from foods that were not part of our ancestral diets and are not compatible with our metabolism. Additionally, multiple nutrient-independent factors, e.g., cost, accessibility, behaviours, culture, education, work commitments, knowledge and societal set-up, influence our food choices and eating patterns. Much research has been focused on 'what to eat' or 'how much to eat' to reduce the obesity burden, but increasingly evidence indicates that 'when to eat' is fundamental to human metabolism. Aligning feeding patterns to the 24-h circadian clock that regulates a wide range of physiological and behavioural processes has multiple health-promoting effects with anti-obesity being a major part. This article explores the current understanding of the interactions between the body clocks, bioactive dietary components and the less appreciated role of meal timings in energy homeostasis and obesity.

High-Fat-Diet-Evoked Disruption of the Rat Dorsomedial Hypothalamic Clock Can Be Prevented by Restricted Nighttime Feeding

Obesity is a growing health problem for modern society; therefore, it has become extremely important to study not only its negative implications but also its developmental mechanism. Its links to disrupted circadian rhythmicity are indisputable but are still not well studied on the cellular level. Circadian food intake and metabolism are controlled by a set of brain structures referred to as the food-entrainable oscillator, among which the dorsomedial hypothalamus (DMH) seems to be especially heavily affected by diet-induced obesity. In this study, we evaluated the effects of a short-term high-fat diet (HFD) on the physiology of the male rat DMH, with special attention to its day/night changes. Using immunofluorescence and electrophysiology we found that both cFos immunoreactivity and electrical activity rhythms become disrupted after as few as 4 weeks of HFD consumption, so before the onset of excessive weight gain. This indicates that the DMH impairment is a possible factor in obesity development. The DMH cellular activity under an HFD became increased during the non-active daytime, which coincides with a disrupted rhythm in food intake. In order to explore the relationship between them, a separate group of rats underwent time-restricted feeding with access to food only during the nighttime. Such an approach completely abolished the disruptive effects of the HFD on the DMH clock, confirming its dependence on the feeding schedule of the animal. The presented data highlight the importance of a temporally regulated feeding pattern on the physiology of the hypothalamic center for food intake and metabolism regulation, and propose time-restricted feeding as a possible prevention of the circadian dysregulation observed under an HFD.

Potential Role of the Circadian Clock in the Regulation of Cancer Stem Cells and Cancer Therapy

Circadian rhythms, including sleep/wake cycles as well as hormonal, immune, metabolic, and cell proliferation rhythms, are fundamental biological processes driven by a cellular time-keeping system called the circadian clock. Disruptions in these rhythms due to genetic alterations or irregular lifestyles cause fundamental changes in physiology, from metabolism to cellular proliferation and differentiation, resulting in pathological consequences including cancer. Cancer cells are not uniform and static but exist as different subtypes with phenotypic and functional differences in the tumor microenvironment. At the top of the heterogeneous tumor cell hierarchy, cancer stem cells (CSCs), a self-renewing and multi-potent cancer cell type, are most responsible for tumor recurrence and metastasis, chemoresistance, and mortality. Phenotypically, CSCs are associated with the epithelial-mesenchymal transition (EMT), which confers cancer cells with increased motility and invasion ability that is characteristic of malignant and drug-resistant stem cells. Recently, emerging studies of different cancer types, such as glioblastoma, leukemia, prostate cancer, and breast cancer, suggest that the circadian clock plays an important role in the maintenance of CSC/EMT characteristics. In this review, we describe recent discoveries regarding how tumor intrinsic and extrinsic circadian clock-regulating factors affect CSC evolution, highlighting the possibility of developing novel chronotherapeutic strategies that could be used against CSCs to fight cancer.

Shift Work and the Risk of Cardiometabolic Multimorbidity Among Patients With Hypertension: A Prospective Cohort Study of UK Biobank

Background Although the association between shift work and individual cardiometabolic diseases has been well studied, its role in the progression to cardiometabolic multimorbidity (CMM) remains unclear. In this study, we investigate the association between shift work and the incidence of CMM in patients with hypertension. Methods and Results This study is a population-based and prospective cohort study on 36 939 UK Biobank participants. We used competing risk models to examine the association between shift work and the risk of CMM, which was defined as coexistence of hypertension and diabetes, coronary heart disease, or stroke in our study. We also investigated the association between the frequency and duration of shift work and CMM risks. In addition, we conducted a cross-classification analysis with the combination of frequency and duration of shift work, chronotype and sleep duration as the exposure metrics. During a median follow-up of 11.6 years, a total of 5935 participants developed CMM. We found that usually/always night shift workers were associated with a 16% higher risk of CMM compared with day workers (hazard ratio [HR], 1.16 [95% CI, 1.02-1.31]). We also found that a higher frequency of night shifts (>10/month) was associated with increased risk of CMM (HR, 1.19 [95% CI, 1.06-1.34]) that was more pronounced for >10/month in combination with a morning chronotype or <7 hours or >8 hours of sleep duration (HR, 1.26 [95% CI, 1.02-1.56]; HR, 1.43 [95% CI, 1.19-1.72], respectively). Conclusions We find that night shift work is associated with higher CMM risk in patients with hypertension.

Exposure to artificial light at night: A common link for obesity and cancer?

Exposure to artificial light at night (ALAN) has been associated with disruption of the circadian system, which has been pointed out to have detrimental effects on health. Exposure to outdoor ALAN is very frequent in industrialised countries due to nocturnal light pollution and the relevant involvement of the total workforce in shift work and night work. Ecological and epidemiologic studies highlight the association between exposure to ALAN and several diseases, mainly obesity and cancer. More recently, also indoor ALAN exposure has been investigated. Among several multifactorial mechanisms linking ALAN exposure and health risks, suppression of melatonin secretion plays a pivotal role leading to alterations in circadian rhythm patterns, that are detrimental in terms of appetite regulation, and dysfunctions in metabolic signalling and cell growth in cancer. In addition, gut dysbiosis, inflammation, hypovitaminosis D, imbalance in cytokine secretion and levels are responsible for the multiple relationship linking circadian dysregulation due to ALAN exposure and obesity, and cancer. Therefore, the current manuscript summarises human and basic studies pointing out the impact of ALAN exposure on health, mostly focusing on obesity and cancer. Based on extant evidence, prevention strategies for obesity and cancer should be prompted, targeting exposure to ALAN.

The Circadian Regulation of Nutrient Metabolism in Diet-Induced Obesity and Metabolic Disease

Obesity and other metabolic diseases are major public health issues that are particularly prevalent in industrialized societies where circadian rhythmicity is disturbed by shift work, jet lag, and/or social obligations. In mammals, daylight entrains the hypothalamic suprachiasmatic nucleus (SCN) to a ≈24 h cycle by initiating a transcription/translation feedback loop (TTFL) of molecular clock genes. The downstream impacts of the TTFL on clock-controlled genes allow the SCN to set the rhythm for the majority of physiological, metabolic, and behavioral processes. The TTFL, however, is ubiquitous and oscillates in tissues throughout the body. Tissues outside of the SCN are entrained to other signals, such as fed/fasting state, rather than light input. This system requires a considerable amount of biological flexibility as it functions to maintain homeostasis across varying conditions contained within a 24 h day. In the face of either circadian disruption (e.g., jet lag and shift work) or an obesity-induced decrease in metabolic flexibility, this finely tuned mechanism breaks down. Indeed, both human and rodent studies have found that obesity and metabolic disease develop when endogenous circadian pacing is at odds with the external cues. In the following review, we will delve into what is known on the circadian rhythmicity of nutrient metabolism and discuss obesity as a circadian disease.

Effectiveness and response differences of a multidisciplinary workplace health promotion program for healthcare workers

Background

Workplace health promotion (WHP) in the healthcare industry is an important yet challenging issue to address, given the high workload, heterogeneity of work activities, and long work hours of healthcare workers (HCWs). This study aimed to investigate the effectiveness and response differences of a multidisciplinary WHP program conducted in HCWs.

Methods

This retrospective cohort study included HCWs participating in a multidisciplinary WHP program in five healthcare facilities. The 20-week intervention included multiple easy-to-access 90-min exercise classes, one 15-min nutrition consultation, and behavioral education. Pre- and post-interventional anthropometrics, body composition, and physical fitness (PF) were compared with paired sample t-tests. Response differences across sex, age, weight status, and shiftwork status were analyzed with a generalized estimating equation.

Results

A total of 302 HCWs were analyzed. The intervention effectively improved all anthropometric (body mass index, waist circumference, waist-hip ratio, and waist-to-height ratio), body composition (body fat percentage, muscle weight, visceral fat area), and PF (grip strength, high jump, sit-up, sit-and-reach, step test) parameters in all participants (all p < 0.05). Subgroup analyses revealed shift workers had a more significant mean reduction in body mass index than non-shift workers (adjusted p = 0.045). However, there was no significant response difference across sex, age, and weight subgroups.

Conclusion

This study suggested that a multidisciplinary WHP program can improve anthropometric and PF profiles regardless of sex, age, and weight status for HCWs, and shifter workers might benefit more from the intervention.

A Cross-Sectional, Exploratory Study on the Impact of Night Shift Work on Midwives’ Reproductive and Sexual Health

Background: Shift work is the basis for health care system functioning. The non-standard schedules enforce abrupt changes in the timing of sleep and light-dark exposure. It can contribute to the increased risk of various medical conditions, including reproductive and sexual health issues. The purpose of the study was to assess the impact of shift work with night shifts on midwives’ reproductive and sexual health. Methods: This cross-sectional, exploratory study included 520 midwives. A descriptive questionnaire was distributed in person (414) and online (106) from July 2019 to May 2020. We used the Female Sexual Function Index (PL-FSFI) standardized questionnaire and proprietary research tools (applicable to demographic and social data and reproductive health). All statistical calculations were performed with the IBM SPSS 23 statistical package. Results: Shift work affects midwives’ reproductive and sexual health. Midwives working night shifts are more likely to experience reproductive problems and sexual dysfunctions. The most pronounced differences are observed in the experience of infertility and the number of miscarriages. PL-FSFI results clearly showed the adverse impact of working shifts including night shifts on functioning in various dimensions of sexual health. Conclusion: Shift work negatively affects reproductive and sexual health and causes work-life conflict experience. It is necessary to develop procedures that minimize shift rotation and implement work schedules that allow for recuperation or rest and ensure proper family and social life.

Time-Related Eating Patterns Are Associated with the Total Daily Intake of Calories and Macronutrients in Day and Night Shift Workers

The aim of the study was to investigate whether time-related eating patterns are associated with the daily intake of calories and macronutrients in Brazilian male military police officers (n = 81; 29-day and 52-night workers; mean age: 36.4 ± 0.9 and 38.5 ± 0.7 years, respectively). Energy and macronutrient intake were determined by a non-consecutive 3-day food recall. Time-related eating patterns, such as the time of the first and the last meals, eating duration, and caloric midpoint, were evaluated. Individuals were classified as “early” or “late” eaters according to the median caloric midpoint. Night shift workers showed a later eating time for the last meal (p < 0.001), longer eating duration (p < 0.001), and later caloric midpoint (p = 0.037) than day workers. Late eaters from both workgroups consumed more 24 h energy (p = 0.028), fat in calories (p = 0.006) and protein (calories: p < 0.001; percentage of total calories: p = 0.042), and less carbohydrates in calories (p = 0.010) intake than early eaters. The time of the first meal was negatively correlated with 24 h energy (p = 0.024) and carbohydrate (p = 0.031) intake only in day workers. The time of the last meal was positively correlated with 24 h energy (day workers: β = 0.352; p = 0.044; night workers: β = 0.424; p = 0.002) and protein (day workers: β = 0.451; p = 0.013; night workers: β = 0.536; p < 0.001) intake for both shift workers, and with carbohydrate (β = 0.346; p = 0.016) and fat (β = 0.286; p = 0.042) intake only in night workers. Eating duration was positively correlated with energy (day workers: β = 0.473; p = 0.004; night workers: β = 0.320; p = 0.023) and carbohydrate (day workers: β = 0.418; p = 0.011; night workers: β = 0.364; p = 0.010) intake in both groups. Thus, time-related eating patterns indicative of intake later at night are associated with increased daily energy and macronutrient intake.

An exploratory study of associations between sleep timing variability and cardiometabolic health in middle-aged adults with type 2 diabetes mellitus

Sleep is increasingly recognised as an important risk factor for metabolic disease, and as an important influence on severity in established metabolic disease. Recent evidence suggests that sleep timing variability (the day-to-day fluctuations of sleep timing) may be an important factor in metabolic diseases such as type 2 diabetes mellitus. In the current study, we explore the associations between measures of sleep timing variability and cardiometabolic measures in a group of healthy middle-aged adults with and without type 2 diabetes mellitus. Healthy controls (N = 27) and adults with well-controlled uncomplicated type 2 diabetes mellitus (N = 30) wore actiwatches for an average of 9 days for objective assessment of sleep timing parameters, and also underwent a detailed clinical assessment. We found greater self-reported social jetlag in the diabetes group, but no groupwise differences in measures of sleep timing variability. In the diabetes patients, HbA1c levels were inversely correlated with variability in the time of sleep onset and midsleep, and with sleep duration. HOMA-IR did not correlate with any sleep timing variability measure, nor were there associations between sleep timing variability and other metabolic biomarkers (cholesterol, LDL, HDL, triglycerides and uric acid). Systolic blood pressure was inversely correlated with actigraphically defined social jetlag in both the control and diabetes groups. The results of this study indicate associations between sleep timing variability and HbA1c, but the direction of these relationships is at variance with some other recent reports. Our results indicate a need for future hypothesis-testing studies to further explore the impact of sleep timing variance on metabolic health.

Age and Sex Differences in the Association of Sleep Duration and Overweight/Obesity among Chinese Participants Age above 45 Years: A Cohort Study

OBJECTIVES

We aimed to evaluate the association between sleep duration and obesity and estimate the attributable risk of sleep in the China Health and Retirement Longitudinal Study surveys (CHARLS).

METHODS

A total of 9061 adults aged 45 years above from CHARLS (2011-2015) were included. The main outcome of this study was incident overweight/obesity specific to general and abdominal obesity. Overweight/obesity was defined as BMI ≥ 23.0 (kg/m2) and BMI≥27.5 (kg/m2), respectively. Abdominal obesity was defined as waist circumference ≥90 cm for men and ≥80 cm for women. Self-reported sleep durations were obtained using a structured questionnaire. We assessed hazard ratios (HRs) and 95% confidence intervals (CIs) as well as the population attributable fraction (PAF) for associations between sleep duration and obesity.

RESULTS

986 and 606 participants were identified as overweight and general obesity respectively, 1253 experienced abdominal obesity events. In multivariable-adjusted models, participants with daytime sleep of 0-30 minutes and more than 30 minutes associated with 30% (HR: 0.70, 95% CI: 0.56-0.87) and 35% (HR: 0.65, 95% CI: 0.55-0.78) decreased incident overweight risk respectively compared to those having no daytime sleep, this association also found among females and middle-aged, not males or elderly. Similarly, 0-30 minutes (HR: 0.68, 95% CI: 0.48-0.96) and more than 30 minutes of daytime sleep (HR: 0.73, 95% CI: 0.59-0.91) were associated with a reduced risk of abdominal obesity, similar results also found among females and middle-aged. Compared with 7-9 hours of nocturnal sleep, people who slept 5-7 hours had a reduced risk of overweight (HR: 0.59, 95% CI=0.47-0.74),but not found in subgroups. The hazard role of long nocturnal sleep for abdominal obesity was only found among elderly (HR: 2.33, 95% CI=1.35-4.04) and males (HR: 2.24, 95% CI=1.17-4.29). Compared with moderate total sleepers (7-9hours/day), participants with short total sleep duration exhibited an elevated risk of overweight (HR: 1.13, 95% CI=1.00-1.28), this also found among middle-aged. The PAF for inadequate total sleep duration (<7 hours/day) was 10.77% for overweight individuals.

CONCLUSIONS

Insufficient sleep duration was associated with an elevated risk of overweight only detected among middle-aged not elderly and other subgroups specific by age. The risks for abdominal obesity were increased for males and middle-aged with long nocturnal sleep. Daytime sleep may significantly reduce the risk of overweight and abdominal obesity in female and middle-aged individuals. The link between sleep duration and obesity requires further study.

The association between metabolic parameters and evening chronotype and social jetlag in non-shift workers: A meta-analysis

AIMS

The aim of the study was to evaluate the association between evening chronotype and social jetlag (SJL) with obesity, blood glucose and lipid levels in non-shift working adults.

METHODS

The databases of MEDLINE, EMBASE and Cochrane Reviews were searched for studies analyzing the metabolic parameters among groups of different chronotypes or SJL until Feb 2022. Weighted mean difference (WMD) and 95% confidence intervals (CI) were used to analyze the association between these parameters and chronotypes or SJL.

RESULTS

A total of 27 studies were included in this meta-analysis. Compared with morning chronotype, the participants with evening chronotype had higher body mass index (BMI) (WMD= 0.44 kg/m², 95%CI, 0.30 to 0.57 kg/m², p<0.001), higher fasting blood glucose level (WMD= 5.83mg/dl, 95%CI, 3.27to 8.38 mg/dl, p<0.001), higher total cholesterol level (WMD= 6.63mg/dl, 95%CI, 0.69 to 12.56 mg/dl, p=0.03), and lower high density lipoprotein cholesterol (HDL-C) level (WMD= -1.80mg/dl, 95%CI, -2.30 to -1.31 mg/dl, p<0.001). Compared with the participants with small SJL, the participants with large SJL had larger waist circumference (WMD= 0.80cm, 95%CI, 0.77 to 0.83cm, p<0.001).

CONCLUSIONS

Evening chronotype and SJL were associated with obesity and unfavorable metabolic parameters of glucose and lipid metabolism.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022303401.

Is it chicken or the egg: Obesity, anxiety and depression in hospital workers

BACKGROUND: Healthcare workers are susceptible to obesity, anxiety and depression. OBJECTIVE: To determine the prevalence and association of obesity, anxiety and depression symptoms in individuals working in a hospital. METHODS: In this cross-sectional study all of the employees of a hospital were invited to participate (n = 150). Anxiety (via Beck Anxiety Scale) and depression symptoms (via Beck Depression Scale) and obesity were dependent and independent variables. Obesity was determined both with body mass index (BMI) and abdominal obesity (Waist circumference-WC). Data were collected with face-to-face interviews and anthropometric measurements were done. Data were analyzed using SPSS version 25.0 with student t-test, chi-square and correlation tests. Significance was set at a p-value <  0.05. RESULTS: Among the participants who agreed to participate (n = 131, 64.1% females), 35.1% were obese and 50.4% were abdominally obese. The 35.9% had moderate-severe anxiety symptoms, 19.1% had moderate-severe depression symptoms. Both BMI and WC had positive, moderate and significant correlation with anxiety and depression scores. After adjusting for socio-demographic variables obesity (both with BMI and WC) was an independent factor for anxiety and depression symptom presence, whereas after adjusted for these variables anxiety and depression symptom presence was an independent factor for obesity and abdominal obesity (p = 0.001 for all). CONCLUSIONS: There is a correlation between anxiety, depression and obesity. In addition to nutrition interventions in combating obesity, services that will improve mental health should be provided together as teamwork.

Influence of shift work on rest-activity rhythms, sleep quality, and fatigue of female nurses

Female nurses working rotating shifts must change their daily routines often, which affects their biological circadian rhythms and could cause sleep disorders and fatigue. The objective of this study was to compare the sleep-wake rhythms, sleep quality, and fatigue of female nurses working rotating shifts and fixed day shifts and to analyze the factors that influence their fatigue. Participants comprised a shift worker group of 101 nurses and a day worker group of 76 nurses. Following the collection of basic information of the nurses and their scores in the various constructs of the Pittsburg Sleep Quality Index (PSQI) and the Checklist Individual Strength (CIS) questionnaire, each nurse wore an actigraph for seven consecutive days to collect for analysis the sleep-wake rhythm parameter dichotomy index (I < O) and durations of continuous sleep and wake. Multivariable linear regression was then used to determine whether the influence of various variables on fatigue differed between the two groups. Results revealed that the sleep-wake rhythm parameter I < O of the day worker group was significantly higher than that of the shift worker group (t = 5.08, p < .001). The shift worker group exhibited significantly higher PSQI global scores (t = -2.00, p = .047), longer total sleep time (t = 2.07, p = .040), poorer habitual sleep efficiency (t = -3.06, p = .003), and greater use of sleeping medication (t = -2.90, p = .004) than did the day worker group. Multivariable linear regression was performed to analyze the important predictors of the CIS score in the two groups with body mass index, age, work experience, marital status, educational background, department of employment, shift type at the time of recruitment, sleep-wake rhythm parameter I < O, and quality of sleep as independent variables. Results indicated that in the shift worker group, the overall explanatory power (R²) of the multivariable linear regression model was 22.9% (F = 3.01, p = .003), and only the PSQI global score (β = 0.33, p = .003) influenced the CIS score. In the day worker group, the various variables did not influence the CIS score in the multivariable linear regression model. Although the female nurses working rotating shifts spent more time in bed, their sleep-wake rhythms and sleep quality were poorer than those of the day worker group. Furthermore, the sleep quality of female nurses in the shift worker group had a significant impact on their fatigue. In other words, for female nurses who must work rotating shifts, sleep quality determines whether fatigue can be reduced. The shift-working nurses themselves should implement sleep management, such as avoiding disruptions to their sleep-wake rhythm and improving sleep quality, which should be effective strategies to reduce fatigue.

No Significant Effect of the Individual Chronotype on the Result of Moderate Calorie Restriction for Obesity-A Pilot Study

BACKGROUND

Chronotype is the pattern of the circadian rhythm that allows an individual to optimize times of sleep and activity. It has been observed that chronotypes may associate with some conditions and diseases, including obesity. It is not known, however, whether chronotypes determine the effectiveness of weight loss regimens. Therefore, in the present study, we compared the outcomes of a 3-week moderate calorie restriction undertaken by individuals with obesity under the same controlled hospital conditions.

METHODS

A total of 131 participants with obesity (median BMI 40.0) were studied. The subjects underwent the same dietary intervention over 3 weeks, with a 30% reduction in daily caloric intake. The individual chronotypes were assessed by the morning and evening questionnaire (MEQ) according to Horne and Östberg. Anthropometric and biochemical parameters were assessed by routine methods.

RESULTS

Of all patients examined, 75% had the morning (lark) chronotype and 25% had the evening (owl) chronotype. These patient sub-groups did not differ in terms of demographic, anthropometric and biochemical characteristics at baseline. After 3 weeks of calorie restriction, both groups experienced a similar loss of weight and BMI (Body Mass Index) (3.4 ± 0.38% for larks vs. 4.1 ± 0.47% for owls, p = 0.45), with owls exhibiting a marginally greater loss of body fat (3.1 ± 0.79%) compared with larks (2.6 ± 0.64%), p = 0.02. On the other hand, the larks had a more discernable, but not statistically significant from owls, decrease in glycated haemoglobin and CRP (C Reactive Protein).

CONCLUSIONS

The chronotype of individuals with obesity does not have a significant effect on the magnitude of the body weight loss, but there is a tendency observed towards the reduction in body fat content in owls through changing their meal and sleep timing to earlier hours, in response to moderate calorie restriction applied under the same controlled conditions.

Is Shift Work Sleep Disorder a Risk Factor for Metabolic Syndrome and Its Components? A Systematic Review of Cross-Sectional Studies

Shift work sleep disorder is prevalent in night shift workers due to prolonged misalignment of the circadian rhythm. Night shift workers comprise a significant portion of the workforce and it is important to study the potential implications on their health. Studies have shown the association of metabolic syndrome (MetS) and the components, that is, obesity, dyslipidemia, hypertension, and insulin resistance, with shift workers. Nocturnal exposure to bright light can affect various physiological processes including melatonin secretion, which is a regulator in insulin synthesis. A systematic review was conducted to identify studies showing the association between shift work and MetS and/or its components, as well as to review the pathophysiology for further investigations. This review follows the guidelines as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist 2009. One thousand nine hundred ten records were identified from the PubMed database using both keywords and medical subject headings terms. After applying the inclusion/exclusion and eligibility criteria, 18 observational studies were included in the qualitative synthesis. Quality appraisal was conducted by two investigators independently using the Newcastle/Ottawa Scale, and 11 articles were finalized for the review after scoring 60% and above. Each study measured the different components of MetS and/or the presence of MetS. Statistically significant results were reported for the association between shift work and MetS, shift work and obesity, shift work and dyslipidemia, shift work and hypertension, and shift work and insulin resistance. This review identifies a need to emphasize treatment plans for shift workers to manage not only sleep disorders but other chronic diseases such as MetS, obesity, hypertension, dyslipidemia, and insulin resistance.

Roles of circadian clocks in cancer pathogenesis and treatment

Circadian clocks are ubiquitous timing mechanisms that generate approximately 24-h rhythms in cellular and bodily functions across nearly all living species. These internal clock systems enable living organisms to anticipate and respond to daily changes in their environment in a timely manner, optimizing temporal physiology and behaviors. Dysregulation of circadian rhythms by genetic and environmental risk factors increases susceptibility to multiple diseases, particularly cancers. A growing number of studies have revealed dynamic crosstalk between circadian clocks and cancer pathways, providing mechanistic insights into the therapeutic utility of circadian rhythms in cancer treatment. This review will discuss the roles of circadian rhythms in cancer pathogenesis, highlighting the recent advances in chronotherapeutic approaches for improved cancer treatment.

Obesity and sleep disturbances: The "chicken or the egg" question

Obesity and sleep disturbances are common conditions in modern societies and accumulating evidence support a close bidirectional causal relationship between these two conditions. Indeed, from one side sleep loss seems to affect energy intake and expenditure through its direct effects on hormone-mediated sensations of satiety and hunger and through the influence on hedonic and psychological aspects of food consumption. Sleep deprived patients have been shown to experiment excessive daytime sleepiness, fatigue, and tiredness that, in a vicious circle, enhances physical inactivity and weight gain. On the other side, obesity is a well-known risk factor for several sleep disorders. This narrative review will discuss the main pathophysiological mechanisms that link sleep loss to obesity and metabolic syndrome with particular attention to the three most common sleep disorders (insomnia, obstructive sleep apnoea syndrome, restless leg syndrome).

Do Rotating Night Shifts Change Nurses' Nutritional Status? A Cross-Sectional Study

OBJECTIVE

Shift work disrupts circadian rhythms through environmental factors such as disruption of the light-dark and rest-activity cycle. This study aims to evaluate the nutritional status, circadian phenotype, sleep quality, and anthropometric measurements in nurses working in rotating night shifts.

METHOD

The study included 44 nurses working in rotating night shifts. Physical activity records for 4 days and 24-hour dietary recalls for 7 days were taken. To evaluate the circadian phenotypes and sleep quality, the Morningness-Eveningness Questionnaire and the Pittsburg Sleep Quality Index were used, respectively.

RESULTS

Most nurses were evening chronotype and had poor sleep quality. Shift work was associated with higher daily energy intake and lower total daily energy expenditure (p < 0.05). On the night shifts, while fiber-rich foods such as beans and fruit consumption decrease, the consumption of fats, sweets, and cereals increases. While carbohydrates, total fat, and cholesterol intake were higher in only women on the night shift (p < 0.05), saturated fat and calcium intake were higher in all nurses (p < 0.05). While the water intake of the nurses was lower on the night shift (p < 0.05), tea intake was higher in women (p < 0.05). A correlation was found between total shift work duration, body mass index (r = 0.525), waist circumference (r = 0.577), waist-height ratio (r = 0.584), and body fat percentage (r = 0.513) (p < 0.001).

CONCLUSIONS

Nurses should be encouraged to ensure adequate water intake and to make healthy food choices during the night shift to maintain health and work performance.

Eat, Train, Sleep-Retreat? Hormonal Interactions of Intermittent Fasting, Exercise and Circadian Rhythm

The circadian rhythmicity of endogenous metabolic and hormonal processes is controlled by a complex system of central and peripheral pacemakers, influenced by exogenous factors like light/dark-cycles, nutrition and exercise timing. There is evidence that alterations in this system may be involved in the pathogenesis of metabolic diseases. It has been shown that disruptions to normal diurnal rhythms lead to drastic changes in circadian processes, as often seen in modern society due to excessive exposure to unnatural light sources. Out of that, research has focused on time-restricted feeding and exercise, as both seem to be able to reset disruptions in circadian pacemakers. Based on these results and personal physical goals, optimal time periods for food intake and exercise have been identified. This review shows that appropriate nutrition and exercise timing are powerful tools to support, rather than not disturb, the circadian rhythm and potentially contribute to the prevention of metabolic diseases. Nevertheless, both lifestyle interventions are unable to address the real issue: the misalignment of our biological with our social time.

Time for Novel Strategies to Mitigate Cardiometabolic Risk in Shift Workers

Circadian disruption induced by shift work is robustly associated with obesity, diabetes, and cardiovascular disease in humans. Less well-known are the mechanisms underlying these associations, and the effectiveness of strategies to reduce cardiometabolic risk in the shift work population. In this review, the different ways in which shift work can deteriorate cardiometabolic health, and how to use this information to reflect on various risk-mitigating strategies, is discussed. While individual strategies appear promising in animal studies, the multifactorial disease risk in shift workers likely requires a multidisciplinary approach. Therefore, the need for individually-tailored combined lifestyle interventions, that could be essential in reducing cardiometabolic disorders in the large population of shift workers in our 24/7 society, is argued.

Night Shift Work, Chronotype, Sleep Duration, and Prostate Cancer Risk: CAPLIFE Study

To analyze the association between prostate cancer (PCa) risk and night shift work, chronotype, and sleep duration in the context of a population-based case-control study of incident prostate cancer in Spain, a total of 465 PCa cases and 410 controls were analyzed. Selection criteria were: (i) age 40-80 years, and (ii) residence in the coverage area of the reference hospitals for ≥6 months before recruitment. Exposure variables were: (i) night shift work (permanent or rotating); (ii) chronotype: morning, neither, or evening (Munich ChronoType Questionnaire) and (iii) sleep duration according to the recommendations of the American National Sleep Foundation. PCa aggressiveness was determined according to the International Society of Urology Pathology classification. Adjusted odds ratios (aOR) and 95% confidence intervals (95% CI) were estimated using logistic regression models. Night shift work was associated with PCa, aOR = 1.47 (95% CI 1.02-2.11), especially for rotating night shifts, aOR = 1.73 (95% CI 1.09-2.75). The magnitude of the association between ever night work and PCa was higher in evening subjects with aOR = 3.14 (95% CI 0.91-10.76) than in morning chronotypes with an aOR = 1.25 (95% CI 0.78-2.00). Working night shifts, especially rotating night shifts, could increase PCa risk. This risk may be higher in people with an evening chronotype.

Individual Circadian Preference, Shift Work, and Risk of Medication Errors: A Cross-Sectional Web Survey among Italian Midwives

Background: In order to explore the possible association between chronotype and risk of medication errors and chronotype in Italian midwives, we conducted a web-based survey. The questionnaire comprised three main components: (1) demographic information, previous working experience, actual working schedule; (2) individual chronotype, either calculated by Morningness–Eveningness Questionnaire (MEQ); (3) self-perception of risk of medication error. Results: Midwives (n = 401) responded “yes, at least once” to the question dealing with self-perception of risk of medication error in 48.1% of cases. Cluster analysis showed that perception of risk of medication errors was associated with class of age 31–35 years, shift work schedule, working experience 6–10 years, and Intermediate-type MEQ score. Conclusions: Perception of the risk of medication errors is present in near one out of two midwives in Italy. In particular, younger midwives with lower working experience, engaged in shift work, and belonging to an Intermediate chronotype, seem to be at higher risk of potential medication error. Since early morning hours seem to represent highest risk frame for female healthcare workers, shift work is not always aligned with individual circadian preference. Assessment of chronotype could represent a method to identify healthcare personnel at higher risk of circadian disruption.