Shiftwork, Sleep Habits, and Metabolic Disparities: Results from the Survey of the Health of Wisconsin

Circadian disruption, clock genes, and metabolic health

A growing body of research has identified circadian-rhythm disruption as a risk factor for metabolic health. However, the underlying biological basis remains complex, and complete molecular mechanisms are unknown. There is emerging evidence from animal and human research to suggest that the expression of core circadian genes, such as circadian locomotor output cycles kaput gene (CLOCK), brain and muscle ARNT-Like 1 gene (BMAL1), period (PER), and cyptochrome (CRY), and the consequent expression of hundreds of circadian output genes are integral to the regulation of cellular metabolism. These circadian mechanisms represent potential pathophysiological pathways linking circadian disruption to adverse metabolic health outcomes, including obesity, metabolic syndrome, and type 2 diabetes. Here, we aim to summarize select evidence from in vivo animal models and compare these results with epidemiologic research findings to advance understanding of existing foundational evidence and potential mechanistic links between circadian disruption and altered clock gene expression contributions to metabolic health-related pathologies. Findings have important implications for the treatment, prevention, and control of metabolic pathologies underlying leading causes of death and disability, including diabetes, cardiovascular disease, and cancer.

Sleep Duration Differences by Education from Middle to Older Adulthood: Does Employment Stratification Contribute to Gendered Leveling?

Sleep duration changes across the life course and differs by education in the United States. However, little research has examined whether educational differences in sleep duration change over age-or whether sleep duration trajectories over age differ by education. This study uses a life course approach to analyze American Time Use Survey data (N = 60,908), examining how educational differences in weekday sleep duration change from middle to older adulthood (ages 40-79). For men only, differences in total sleep time between individuals with less than a high school degree and those with more education converge in older adulthood. Results suggest that this leveling is explained by decreasing educational stratification in work hours as men enter older adulthood. Findings highlight the importance of employment for shaping gendered socioeconomic differences in sleep and demonstrate differences by education in how sleep duration changes over age, with possible implications for health disparities.

Poor sleep quality and overweight/obesity in healthcare professionals: a cross-sectional study

Objective

This study aimed to analyze the relationship between the sleep quality of healthcare professionals and the incidence of overweight and obesity, exploring the potential impact of sleep quality on the onset of overweight and obesity in order to provide a scientific basis for formulating effective health intervention measures.

Methods

A convenience sampling method was used to conduct a survey on the sleep characteristics and obesity status among healthcare professionals at Peking Union Medical College Hospital and Tianjin Dongli District Traditional Chinese Medicine Hospital. The survey was conducted via online questionnaires, which included demographic data, the Pittsburgh Sleep Quality Index (PSQI), height, weight, and related sleep, exercise, and dietary habits. Univariate and multivariate logistic regression analyses were applied to study the relationship between sleep quality and overweight/obesity among healthcare professionals.

Results

A total of 402 questionnaires were distributed, with a 100% retrieval rate, yielding 402 valid questionnaires. The average body mass index of the 402 participants was 23.22 ± 3.87 kg/m^2. Among them, 144 cases were overweight or obese, accounting for 35.8% (144/402) of the total. The prevalence of poor sleep quality among healthcare professionals was 27.4% (110/402), with an average PSQI score of 8.37 ± 3.624. The rate of poor sleep quality was significantly higher in the overweight and obese group compared to the normal weight group (36.1% vs. 22.5%, p = 0.003). The multivariate analysis indicated that gender, marital status, lower education level, sleep duration (odds ratio [OR] =1.411, 95% confidence interval [CI] 1.043-1.910, p = 0.026), and sleep disturbances (OR = 1.574, 95%CI 1.123-2.206, p = 0.008) were significant risk factors for overweight and obesity among healthcare professionals.

Conclusion

Overweight or obese healthcare professionals had poorer sleep quality compared to those with a normal weight. Sleep duration and sleep disorders were identified as independent risk factors for overweight or obesity in healthcare professionals. Increasing sleep duration and improving sleep disorders may play a positive role in controlling overweight and obesity among healthcare professionals.

Disparities in Sleep-Disordered Breathing: Upstream Risk Factors, Mechanisms, and Implications

Sleep-disordered breathing (SDB) refers to a spectrum of disorders ranging from habitual snoring without frank episodes of obstructed breathing or desaturation during sleep to obstructive sleep apnea, where apneas and hypopneas repetitively occur with resultant intermittent hypoxia, arousal, and sleep disruption. Disparities in SDB reflect its overall high prevalence in children and adults from racially and ethnically minoritized or low socioeconomic status backgrounds coupled with high rates of underdiagnosis and suboptimal treatment.

Shift Work Disorder Index: initial validation and psychosocial associations in a sample of nurses

STUDY OBJECTIVES

Shift work is common yet does not always result in Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5)-defined shift work sleep disorder (SWD). This study reports on the reliability and validity of the DSM-5 informed Shift Work Disorder Index (SWDI), the presence of probable SWD in nurses, and demographic, sleep, and psychosocial correlates.

METHODS

Nurses (n = 454) completed the SWDI, psychosocial, and demographic questionnaires. Of the sample, n = 400 completed 14 days of sleep diaries, actigraphy, and additional questionnaires.

RESULTS

The global SWDI demonstrated excellent internal consistency (α = .94), as well as good convergent and divergent validity in the nurse sample. Thirty-one percent of nurses were past-month shift workers, with 14% (ie, 44% of shift workers) having probable SWD based on SWDI. Nurses who worked shift work and/or met SWD criteria were more likely to be younger and unmarried and less likely to have children than day workers and reported greater evening chronotype, insomnia, nightmares, and sleep-related impairment, greater depression, anxiety, posttraumatic stress, and perceived stress symptoms, as well as later and more variable sleep midpoint (actigraphy), shorter sleep duration (actigraphy, diaries), and lower sleep efficiency (diaries).

CONCLUSIONS

The SWDI is an efficient and valid self-report assessment of DSM-5-defined SWD. Shift work and/or SWD were prevalent and associated with worse sleep and psychosocial health, particularly among nurses with probable SWD.

CITATION

Taylor DJ, Dietch JR, Wardle-Pinkston S, et al. Shift Work Disorder Index: initial validation and psychosocial associations in a sample of nurses. J Clin Sleep Med. 2022;18(10):2339-2351.

Shift Work and Obesity Risk-Are There Sex Differences?

PURPOSE OF REVIEW

Shift work is prevalent among the working population and is linked to an array of adverse health outcomes. This review summarizes current evidence on the relation between shift work and risk of obesity, with a particular emphasis on potential sex differences.

RECENT FINDINGS

Observational data strongly point towards an association between shift work and heightened risk of prevalent and incident obesity, and particularly abdominal obesity. Circadian misalignment and unhealthy lifestyle behaviors are the primary culprits mediating such association. As it pertains to sex differences in the impact of shift work on obesity, few studies have examined this aspect, and findings are conflicting. Shift work is an important risk factor for obesity, with likely multiple biological and behavioral mediators. However, whether there is a sex-dependent vulnerability to the obesogenic effects of shift work is unclear. This area presents opportunities for future research.

The Survey of the Health of Wisconsin (SHOW) Program: An Infrastructure for Advancing Population Health

Introduction

The Survey of the Health of Wisconsin (SHOW) was established in 2008 by the University of Wisconsin (UW) School of Medicine and Public Health (SMPH) with the goals of (1) providing a timely and accurate picture of the health of the state residents; and (2) serving as an agile resource infrastructure for ancillary studies. Today, the SHOW program continues to serve as a unique and vital population health research infrastructure for advancing public health.

Methods

SHOW currently includes 5,846 adult and 980 minor participants recruited between 2008 and 2019 in four primary waves. WAVE I (2008–2013) includes annual statewide representative samples of 3,380 adults ages 21 to 74 years. WAVE II (2014–2016) is a triannual statewide sample of 1,957 adults (age ≥18 years) and 645 children (age 0–17). WAVE III (2017) consists of follow-up of 725 adults from the WAVE I and baseline surveys of 222 children in selected households. WAVEs II and III include stool samples collected as part of an ancillary study in a subset of 784 individuals. WAVE IV consists of 517 adults and 113 children recruited from traditionally under-represented populations in biomedical research including African Americans and Hispanics in Milwaukee, Wisconsin.

Findings to Date

The SHOW resource provides unique spatially granular and timely data to examine the intersectionality of multiple social determinants and population health. SHOW includes a large biorepository and extensive health data collected in a geographically diverse urban and rural population. Over 60 studies have been published covering a broad range of topics including, urban and rural disparities in cardio-metabolic disease and cancer, objective physical activity, sleep, green-space and mental health, transcriptomics, the gut microbiome, antibiotic resistance, air pollution, concentrated animal feeding operations and heavy metal exposures.

Discussion

The SHOW cohort and resource is available for continued follow-up and ancillary studies including longitudinal public health monitoring, translational biomedical research, environmental health, aging, microbiome and COVID-19 research.

Sleep disruption in nonalcoholic fatty liver disease: What is the role of lifestyle and diet?

BACKGROUND

Patients with nonalcoholic fatty liver disease (NAFLD) have sleep disruption. The aim of this study is to understand how underlying factors such as diet, degree of liver disease and morningness-eveningness tendencies contribute to this sleep disruption.

METHODS

Patients with NAFLD were recruited from liver clinics at a University and Veterans Affairs practice. Patients with decompensated cirrhosis were excluded. Patients completed self-reported surveys to evaluate sleep disturbance using the Epworth Sleepiness Scale (ESS) and chronotype (circadian preference) using the morningness-eveningness questionnaire (MEQ). Information on occupation, physical activity and dietary intake were collected at clinic intake. Dietary intake was evaluated via food-frequency questionnaire and analyzed as individual categories or grouped on the basis of dietary composition.

RESULTS

A 54 patients completed the survey; 37% were female. Median ESS was 8 ± 4.2 and 37% of NAFLD patients were found to have sleep disturbance as defined by ESS >10. Sleep disturbance was common in NAFLD regardless of the liver disease stage. Dietary factors, including higher added sugar (P = 0.01), candy intake (P = 0.01), elevated Ferritin level (P = 0.04) and elevated platelet count (P = 0.05), were significantly associated with sleep disturbance. Chronotype, time to sleep, and duration of sleep were not associated with sleep disruption.

CONCLUSIONS

Sleep disruption is present in NAFLD regardless of underlying cirrhosis. Interventions aimed at improving dietary and lifestyle practices such as reduced sugar intake may help mitigate the risk for sleep disruption in NAFLD. Further longitudinal studies are needed to further delineate these links.

Metabolic Syndrome and Its Related Factors among Hospital Employees: A Population-Based Cohort Study

Several studies have reported on metabolic syndrome (MetS) based on cross-sectional designs, which cannot show a long-term result. Information is lacking on MetS and related factors based on a longitudinal cohort. This study aimed to examine the relationship between MetS and related factors for a total of six years among hospital employees. A population-based study was conducted, including 746 staff. A total of 680 staff without MetS in 2012 were enrolled in the analysis for repeated measurement of six years of the longitudinal cohort. Data were retrieved from the hospital’s Health Management Information System. Analyses were performed using Student’s t-test, chi-square test, logistic regression, and generalised estimating equations. Statistical significance was defined as p < 0.05. Hospital employees aged between 31 and 40 (odds ratio (OR) = 4.596, p = 0.009), aged between 41 and 50 (OR = 7.866, p = 0.001), aged greater than 50 (OR = 10.312, p < 0.001), with a body mass index (BMI) of 25.0~29.9 kg/m² (OR = 3.934, p < 0.001), a BMI ≥ 30 kg/m² (OR = 13.197, p < 0.001), higher level of white blood counts (β = 0.177, p = 0.001), alanine aminotransferase (β = 0.013, p = 0.002), and uric acid (β = 0.223, p = 0.005) were at risk of being diagnosed with MetS. The identification of at-risk hospital employees and disease management programs addressing MetS-related factors are of great importance in hospital-based interventions.

The Survey of the Health of Wisconsin (SHOW) Program: An infrastructure for Advancing Population Health Sciences

PURPOSE

The Survey of the Health of Wisconsin (SHOW) was established in 2008 by the University of Wisconsin (UW) School of Medicine and Public Health (SMPH) with the goals of 1) providing a timely and accurate picture of the health of the state residents; and 2) serving as an agile resource infrastructure for ancillary studies. Today SHOW continues to serve as a vital population health research infrastructure.

PARTICIPANTS

SHOW currently includes 5,846 adult and 980 minor participants recruited between 2008-2019 in four primary waves. WAVE I (2008-2013) includes annual statewide representative samples of 3,380 adults ages 21 to 74 years. WAVE II (2014-2016) is a triannual statewide sample of 1957 adults (age ≥18 years) and 645 children. WAVE III (2017) consists of follow-up of 725 adults from the WAVE I and baseline surveys of 222 children in selected households. WAVEs II and III include stool samples collected as part of an ancillary study in a subset of 784 individuals. WAVE IV consist of 517 adults and 113 children recruited from traditionally under-represented populations in biomedical research including African Americans and Hispanics in Milwaukee county, WI.

FINDINGS TO DATE

The SHOW provides extensive data to examine the intersectionality of multiple social determinants and population health. SHOW includes a large biorepository and extensive health data collected in a geographically diverse urban and rural population. Over 60 studies have been published covering a broad range of topics including, urban and rural disparities in cardio-metabolic disease and cancer, objective physical activity, sleep, green-space and mental health, transcriptomics, the gut microbiome, antibiotic resistance, air pollution, concentrated animal feeding operations and heavy metal exposures.

FUTURE PLANS

The SHOW cohort is available for continued longitudinal follow-up and ancillary studies including genetic, multi-omic and translational environmental health, aging, microbiome and COVID-19 research.

ARTICLE SUMMARY

Strengths and limitations: The Survey of the Health of Wisconsin (SHOW) is an infrastructure to advance population health sciences including biological sample collection and broader data on individual and neighborhood social and environmental determinants of health.The extensive data from diverse urban and rural populations offers a unique study sample to compare how socio-economic gradients shape health outcomes in different contexts.The objective health data supports novel interdisciplinary research initiatives and is especially suited for research in causes and consequences of environmental exposures (physical, chemical, social) across the life course on cardiometabolic health, immunity, and aging related conditions.The extensive biorepository supports novel omics research into common biological mechanisms underlying numerous complex chronic conditions including inflammation, oxidative stress, metabolomics, and epigenetic modulation.Ancillary studies, such as the Wisconsin Microbiome Study, have expanded the utility of the study to examine human susceptibility to environmental exposures and opportunities for investigations of the role of microbiome in health and disease.Long-standing partnerships and recent participation among traditionally under-represented populations in biomedical research offer numerous opportunities to support community-driven health equity work.No biological samples were collected among children.The statewide sampling frame may limit generalizability to other regions in the United States.

A workshop report on the causes and consequences of sleep health disparities

Sleep deficiencies, which include insufficient or long sleep duration, poor sleep quality, and irregular timing of sleep, are disproportionately distributed among populations that experience health disparities in the United States. Sleep deficiencies are associated with a wide range of suboptimal health outcomes, high-risk health behaviors, and poorer overall functioning and well-being. This report focuses on sleep health disparities (SHDs), which is a term defined as differences in one or more dimensions of sleep health on a consistent basis that adversely affect designated disadvantaged populations. SHDs appear to share many of the same determinants and causal pathways observed for health outcomes with well-known disparities. There also appears to be common behavioral and biological mechanisms that connect sleep with poorer health outcomes, suggesting a link between SHDs and other health disparities observed within these designated populations. In 2018, the National Institute on Minority Health and Health Disparities, the National Heart, Lung, and Blood Institute, and the Office of Behavioral and Social Sciences Research convened a workshop with experts in sleep, circadian rhythms, and health disparities to identify research gaps, challenges, and opportunities to better understand and advance research to address SHDs. The major strategy to address SHDs is to promote integration between health disparity causal pathways and sleep and circadian-related mechanisms in research approaches and study designs. Additional strategies include developing a comprehensive, integrative conceptual model, building transdisciplinary training and research infrastructure, and designing as well as testing multilevel, multifactorial interventions to address SHDs.

Is shift work associated with a higher risk of overweight or obesity? A systematic review of observational studies with meta-analysis

Background

An increasing number of original studies suggest that exposure to shift work could be associated with the risk of overweight and obesity, but the results remain conflicted and inconclusive. This study aimed to quantitatively synthesize available epidemiological evidence on the association between shift work and the risk of overweight and obesity by a meta-analysis.

Methods

The authors searched PubMed, Embase and the reference lists of all included studies up to April 2017, with a verification search in December 2017. Inclusion criteria were original studies that reported odds ratios, relative risks or hazard ratios (ORs, RRs or HRs, respectively) of at least one outcome of overweight or obesity. Summary risk estimates were calculated by random-effect models.

Results

Twenty-six studies (7 cohort studies, 18 cross-sectional studies and 1 case-control study) involving 311 334 participants were identified. Among these studies, the cut-off points of overweight and obesity varied greatly, so the heterogeneity was substantial; however, the results were stable. Shift work was found to be positively associated with the risk of overweight [RR: 1.25; 95% confidence interval (95% CI): 1.08-1.44] and obesity (RR: 1.17; 95% CI: 1.12-1.22).

Conclusions

Individuals involved in shift work are more likely to become overweight or obese. Appropriate preventive interventions in the organization of shift schedules according to ergonomic criteria would allow shift workers to avoid potential health impairment.

Exposure to neighborhood green space and sleep: evidence from the Survey of the Health of Wisconsin

INTRODUCTION

Adequate sleep duration and quality are protective against many adverse health outcomes. Many individual-level predictors of poor sleep have been examined, but few studies have examined neighborhood-level influences. Despite known associations between neighborhood green space and sleep influencing factors (eg, physical activity, mental health), few studies have examined green space and sleep's relationship. Furthermore, little work has examined the relationship between the magnitude and type of neighborhood sounds and sleep.

STUDY METHODS

We analyzed data from the Survey of the Health of Wisconsin database (n = 2712) for 2008-2013, a representative sample of Wisconsin residents ages 21-74. Outcomes included weekday and weekend sleep duration and self-rated sleep quality. Primary predictors were the proportion tree canopy (National Land Cover Database) and mean decibel levels of outdoor sound (US National Park Service) at the census block group level. Survey regression analysis was used to examine statistical associations, controlling for individual and neighborhood-level covariates.

RESULTS

Models suggest a significant relationship (P < .05) between weekday sleep duration and green space, and between weekend/day sleep duration and human-made and total neighborhood sound. Increased percent tree canopy in a census block group was associated with lower odds of short weekday sleep (<6 hours) (OR 0.76 [0.58-0.98]). Increased human-made and total mean decibel levels were associated with increased instances of short weekend and weekday sleep (OR 1.05 [1.01-1.08] and 1.03 [1.01-1.06] respectively).

CONCLUSIONS

Neighborhood tree canopy and sound levels may influence sleep duration and are potential targets for neighborhood-level interventions to improve sleep.

Meta-analysis on shift work and risks of specific obesity types

AIMS

This systematic review and meta-analysis evaluated the associations between shift work patterns and risks of specific types of obesity.

METHODS

PubMed was searched until March 2017 for observational studies that examined the relationships between shift work patterns and obesity. Odds ratio for obesity was extracted using a fixed-effects or random-effects model. Subgroup meta-analyses were carried out for study design, specific obesity types and characteristics of shift work pattern.

RESULTS

A total of 28 studies were included in this meta-analysis. The overall odds ratio of night shift work was 1.23 (95% confidence interval = 1.17-1.29) for risk of obesity/overweight. Cross-sectional studies showed a higher risk of 1.26 than those with the cohort design (risk ratio = 1.10). Shift workers had a higher frequency of developing abdominal obesity (odds ratio = 1.35) than other obesity types. Permanent night workers demonstrated a 29% higher risk than rotating shift workers (odds ratio 1.43 vs. 1.14).

CONCLUSION

This meta-analysis confirmed the risks of night shift work for the development of overweight and obesity with a potential gradient association suggested, especially for abdominal obesity. Modification of working schedules is recommended, particularly for prolonged permanent night work. More accurate and detailed measurements on shift work patterns should be conducted in future research.

Exosomes and Metabolic Function in Mice Exposed to Alternating Dark-Light Cycles Mimicking Night Shift Work Schedules

Sleep is an important modulator of metabolic function. Disruptions of sleep in circadian rhythm are common in modern societies and are associated with increased risk of developing cardiometabolic disorders. Exosomes are ubiquitous extracellular vesicles that may play a mechanistic role in metabolic derangements. We hypothesized that alternating dark-light cycles mimicking shift work in mice would alter fecal microbiota and colonic epithelium permeability and alter plasma exosome cargo and metabolic function. C57BL/6 mice were randomly assigned to (i) control day light (CL), or (ii) inverted dark-light every 2 weeks for 8 weeks (IN). Body weight, fat mass and HOMA-IR were measured, along with Tregs, metabolic, and resident macrophages in visceral white adipose tissue (vWAT). Fecal water samples were incubated with confluent colonic epithelium cell cultures in electric cell-substrate impedance sensing (ECIS) arrays, and plasma exosomes were added to differentiated adipocytes and insulin-induced pAKT/AKT expression changes were assessed by western blots. Mice exposed to IN showed elevated HOMA-IR, and their fecal samples showed altered microbiota which promote increased permeability of the colonic epithelial cell barrier. Plasma exosomes decreased pAKT/AKT responses to exogenous insulin compared to CL, and altered expression of circadian clock genes. Inflammatory macrophages (Ly-6c^high) were increased in IN-exposed vWAT, while Tregs were decreased. Thus, gut microbiota and the cargo of plasma exosomes are altered by periodic shifts in environmental lighting, and effectively alter metabolic function, possibly via induction of systemic inflammation and altered clock expression in target tissues. Further exploration of exosomal miRNA signatures in shift workers and their putative metabolic organ cell targets appears warranted.

Objectively measured short sleep duration and later sleep midpoint in pregnancy are associated with a higher risk of gestational diabetes

BACKGROUND

Experimental and epidemiologic data suggest that among nonpregnant adults, sleep duration may be an important risk factor for chronic disease. Although pregnant women commonly report poor sleep, few studies objectively evaluated the quality of sleep in pregnancy or explored the relationship between sleep disturbances and maternal and perinatal outcomes.

OBJECTIVE

Our objective was to examine the relationship between objectively assessed sleep duration, timing, and continuity (measured via wrist actigraphy) and maternal cardiovascular and metabolic morbidity specific to pregnancy.

STUDY DESIGN

This was a prospective cohort study of nulliparous women. Women were recruited between 16 0/7 and 21 6/7 weeks' gestation. They were asked to wear a wrist actigraphy monitor and complete a daily sleep log for a period of 7 consecutive days. The primary sleep exposure variables were the averages of the following over the total valid nights (minimum 5, maximum 7 nights): short sleep duration during the primary sleep period (<7 h/night), late sleep midpoint (midpoint between sleep onset and sleep offset >5 am), and top quartile of minutes of wake time after sleep onset and sleep fragmentation index. The primary outcomes of interest were a composite of hypertensive disorders of pregnancy (mild, severe, or superimposed preeclampsia; eclampsia; or antepartum gestational hypertension) and gestational diabetes mellitus. We used χ² tests to assess associations between sleep variables and categorical baseline characteristics. Crude odds ratios and 95% confidence intervals were estimated from univariate logistic regression models to characterize the magnitude of the relationship between sleep characteristics and hypertensive disorders of pregnancy and gestational diabetes. For associations significant in univariate analysis, multiple logistic regression was used to explore further the association of sleep characteristics with pregnancy outcomes.

RESULTS

In all, 901 eligible women consented to participate; 782 submitted valid actigraphy studies. Short sleep duration and a later sleep midpoint were associated with an increased risk of gestational diabetes (odds ratio, 2.24; 95% confidence interval, 1.11-4.53; and odds ratio, 2.58; 95% confidence interval, 1.24-5.36, respectively) but not of hypertensive disorders. A model with both sleep duration and sleep midpoint as well as their interaction term revealed that while there was no significant interaction between these exposures, the main effects of both short sleep duration and later sleep midpoint with gestational diabetes remained significant (adjusted odds ratio, 2.06; 95% confidence interval, 1.01-4.19; and adjusted odds ratio, 2.37; 95% confidence interval, 1.13-4.97, respectively). Additionally, after adjusting separately for age, body mass index, and race/ethnicity, both short sleep duration and later sleep midpoint remained associated with gestational diabetes. No associations were demonstrated between the sleep quality measures (wake after sleep onset, sleep fragmentation) and hypertensive disorders or gestational diabetes.

CONCLUSION

Our results demonstrate a relationship between short sleep duration and later sleep midpoint with gestational diabetes. Our data suggest independent contributions of these 2 sleep characteristics to the risk for gestational diabetes in nulliparous women.

Obstructive sleep apnea: in search of precision

Introduction

Obstructive sleep apnea (OSA) is a highly prevalent condition that is viewed as a major global health concern, while affecting approximately 10% of the middle-aged population. OSA is a chronic disease that has been conclusively associated with poor quality of life, cognitive impairments and mood alterations, enhanced cardiovascular and metabolic morbidity, thereby leading to marked increments in healthcare costs.

Areas covered

The authors have reviewed the current evidence on the pathophysiology of OSA and its consequences, the heterogeneity of its phenotypic expression, the current therapeutic applications and their efficacy, and the implications for diagnosis, treatment and follow-up strategies in the context of the clinical management of OSA.

Expert commentary

Personalized medicine in OSA identifies different needs and approaches: i) phenotyping and defining the different and segregated clusters of OSA patients whose recognition may improve prognostic predictions and guide therapeutic strategies; ii) to further characterize and predict the impact of OSA and its treatment, particularly revolving around mortality and the processes closely related to ageing (cardiovascular diseases, cancer and neurocognitive diseases); iii) the introduction of new technologies including telemedicine that have shown promise in the implementation of personalized medicine approaches.

Adverse metabolic and mental health outcomes associated with shiftwork in a population-based study of 277,168 workers in UK biobank<sup/>

BACKGROUND

Reported associations between shiftwork and health have largely been based on occupation-specific, or single sex studies that might not be generalizable to the entire working population. The objective of this study was to investigate whether shiftwork was independently associated with obesity, diabetes, poor sleep, and well-being in a large, UK general population cohort.

METHODS

Participants of the UK Biobank study who were employed at the time of assessment were included. Exposure variables were self-reported shiftwork (any shiftwork and night shiftwork); and outcomes were objectively measured obesity, inflammation and physical activity and self-reported lifestyle, sleep and well-being variables, including mental health.

RESULTS

Shiftwork was reported by 17% of the 277,168 employed participants. Shiftworkers were more likely to be male, socioeconomically deprived and smokers, and to have higher levels of physical activity. Univariately, and following adjustment for lifestyle and work-related confounders, shiftworkers were more likely to be obese, depressed, to report disturbed sleep, and to have neurotic traits.

CONCLUSIONS

Shiftwork was independently associated with multiple indicators of poor health and wellbeing, despite higher physical activity, and even in shiftworkers that did not work nights. Shiftwork is an emerging social factor that contributes to disease in the urban environment across the working population. Key messages Studies have linked shiftwork to obesity and diabetes in nurses and industry workers, but little is known about the implications of shiftwork for the general workforce In this large cross sectional study of UK workers, shiftwork was associated with obesity, depression and sleep disturbance, despite higher levels of physical activity. Shiftwork was associated with multiple indicators of compromised health and wellbeing and were more likely to report neurotic traits and evening preference.

Shiftwork Is Not Associated with Increased Risk of NAFLD: Findings from the National Health and Nutrition Examination Survey

AIMS

There is increased focus on the metabolic impact of shiftwork, especially given the significant number of employees who work nighttime or rotating shifts. Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. We conducted a cross-sectional study to examine the association between shiftwork and the risk of NAFLD.

METHODS

We used aggregated data from the 2005-2006, 2007-2008, and 2009-2010 cycles of the National Health and Nutrition Examination Survey (NHANES). We defined NAFLD by elevated serum alanine aminotransferase (ALT) or aspartate aminotransferase (AST) levels (males: AST > 40 or ALT > 37; females: AST > 31 or ALT > 31) in the absence of excessive alcohol use and viral hepatitis. We defined shiftworkers as participants who self-reported currently working regular night shifts or rotating shifts. We calculated adjusted odds ratios (OR) and 95% confidence intervals (CI) using multivariable logistic regression.

RESULTS

Overall, 8159 participants aged 20-79 years reported working at a job or business using the NHANES Occupation Questionnaire and were included in the analysis. Of these, 11.1% were classified as shiftworkers. Compared to non-shiftworkers, shiftworkers were younger, were less likely to be non-Hispanic White, and have health insurance or health care. The overall prevalence of NAFLD was 15.7%. NAFLD occurred more frequently in shiftworkers (17.0%) than non-shiftworkers (15.5%). However, in the overall multivariable analysis, shiftwork was not associated with the risk of NAFLD (OR 1.11, 95% CI 0.87-1.43).

CONCLUSIONS

The findings from this NHANES-based cross-sectional study do not support an association between shiftwork and increased risk of NAFLD.