Lifestyle Factors in the Association of Shift Work and Depression and Anxiety

The association between dietary quality, sleep duration, and depression symptoms in the general population: findings from cross-sectional NHANES study

BACKGROUND

Unhealthy lifestyles, which include unhealthy diet and unhealthy sleep duration, have been widely recognized as modifiable risk factors for depressive symptoms. This study aims to explore the associations between dietary quality, sleep duration, and depression symptoms, as well as their combined effects.

METHODS

The NHANES 2007 to 2014 cycles provided the data for this study, in which 19,134 adults aged 20 years and older were included. Unhealthy diet, measured using an average Healthy Eating Index (HEI)-2015 score below the 60th percentile, and unhealthy sleep duration, measured as sleep duration at night less than 7 h or greater than/equal to 9 h, were the primary exposures. Then participants were divided into four different lifestyles. A weighted-multivariable logistic regression was employed, controlling for relevant variables. Furthermore, stratified analyses were conducted to assess the robustness of the findings and identify potential high-risk groups.

RESULTS

The overall prevalence of depressive symptoms among all participants was 8.44%. Among the participants, 56.58% met the criteria for healthy sleep duration, and 24.83% scored at or above the 60th percentile on the HEI-2015. Unhealthy diet (OR: 1.40, 95% CI: 1.18-1.67, p < 0.001) and unhealthy sleep duration (OR: 1.94, 95% CI: 1.63-2.31, p < 0.001) exhibited positive associations with depression symptoms. Individuals who maintained an unhealthy diet but healthy sleep duration (OR: 1.60, 95% CI: 1.20-2.13, p = 0.002), healthy diet but unhealthy sleep duration (OR: 2.50, 95% CI: 1.64-3.80, p < 0.001), or an unhealthy diet and unhealthy sleep duration (OR: 2.91, 95% CI: 2.16-3.92, p < 0.001) were significantly associated with depressive symptoms compared to those with a healthy diet and healthy sleep duration, respectively. In stratified analyses, females, middle-aged individuals, those with a college degree or higher education, and individuals who do not meet the recommended level of physical activity exhibit heightened susceptibility to depressive symptoms when exposed to unhealthy diet and unhealthy sleep duration.

CONCLUSION

In summary, our study suggests that individuals affected by the individual and synergistic effect of an unhealthy diet and unhealthy sleep duration are more susceptible to experiencing depressive symptoms.

Association of sleep duration with excess risk of dementia among shift workers in the UK biobank: a population-based cohort study

BACKGROUND

Shift work was associated with elevated dementia risk. Definitive guidelines for sleep duration among shift workers have not been proposed. We aimed to identify sleep durations associated with elimination of excess dementia risk in shift workers.

METHODS

285,213 dementia-free UK Biobank participants at baseline, aged 38-71 years, were enrolled between 2006 and 2010 and followed up through 2022 in this cohort study. Cox proportional hazards models were used to examine the associations between shift work, sleep duration, and risk of dementia.

RESULTS

The 285,213 participants included 49,079 shift workers and 236,134 non-shift workers. Over a median follow-up of 13.8 years, 1887 dementia cases were documented. Current shift workers had significantly higher dementia risk than non-shift workers (hazard ratio [HR] 1.26; 95% CI 1.11-1.42). However, this excess risk was eliminated in shift workers with 8 h of sleep (HR 1.02; 95% CI 0.80-1.29). Analysis of shift work frequency indicated that "sometimes" and "usually/always" shift work were associated with increased dementia risk compared to that of non-shift workers, but excess dementia risk was eliminated in members of either frequency group receiving 8 h of sleep ("sometimes", HR 1.05; 95% CI 0.75-1.48; "usually/always", HR 0.98; 95% CI 0.70-1.35). Both "non-night shift" and "night shift" workers showed increased dementia risk compared to non-shift workers. Workers with 8 h of sleep mitigated the excess risk (HR 1.13; 95% CI 0.84-1.53 and HR 0.86; 95% CI 0.59-1.26, respectively).

CONCLUSION

8-h sleep may eliminate excess dementia risk among shift workers, suggesting a potentially effective dementia prevention guideline for shift workers.

Association of night-shift work with gambling and problem gambling among workers in Japan: A nationwide cross-sectional study

BACKGROUND AND AIMS

Night-shift work disturbs sleep and is associated with poor health conditions among workers. We aimed to investigate the association between night-shift work and gambling among workers and the association between night-shift work and problem gambling in working and gambling participants.

METHODS

This cross-sectional study used data from an online survey conducted between February 6 and 27, 2023 in Japan. A total of 21,134 workers participated in this study, including 9,739 respondents who had gambled in the past year. We estimated the association between night-shift work and gambling among workers and the association between night-shift work and problem gambling among those who gambled at the survey. We defined problem gambling as a score ≥ 8 on the Problem Gambling Severity Index. All estimates were weighted using a nationally representative survey in Japan. We fitted multivariable weighted logistic regression models after adjusting for 14 confounders.

RESULTS

The weighted prevalence of gambling among non-night and night-shift workers was 42.1 % and 55.4 %, respectively. When focusing on workers gambling in the survey, the prevalence of problem gambling among non-night and night-shift workers was 8.8 % and 24.2 %, respectively. The weighted multivariable logistic regression analyses showed that night-shift work was associated with gambling participation among workers (adjusted odds ratio [aOR], 1.39, 95 % confidence interval [CI] 1.25-1.53, p < 0.001). In addition, night-shift work was associated with problem gambling among those who gambled (aOR 1.94, 95 % CI 1.57-2.40, p < 0.001).

CONCLUSIONS

Night-shift work was associated with gambling among workers and with problem gambling among those who gambled.

Obesity mediates the relationship between depression and infertility: insights from the NHANES 2013-2018 cross-sectional study and a Mendelian randomization study

Background

Depression is increasingly recognized as a factor affecting infertility and the causal relationship between them remains controversial. The aim of this study was to explore the relationship between depression and infertility using Mendelian randomization (MR) and cross-sectional study, and to explore the potential mediating role of obesity.

Methods

The cross-sectional study used data from the National Health and Nutrition Examination Survey (NHANES) 2013-2018. Multivariable-adjusted logistic regression was used to assess the association between depression and infertility risk, and mediation analysis was to examine the mediating effect of obesity. Then, we performed MR analyses to investigate the causal effect of depression on infertility. Instrumental variables for depression were obtained from a genome-wide association meta-analysis (135,458 cases and 344,901 controls), and summary level data for infertility were obtained from the FinnGen database (6,481 cases and 68,969 controls).

Results

In the cross-sectional study, a total of 2,915 participants between the ages of 18 and 45 were included, of whom 389 were infertile. We observed that depression was strongly associated with an increased risk of infertility (OR=1.66, 95%CI: 1.19, 2.33), and this relationship remained significant in mild (OR=1.45, 95% CI: 1.09, 1.93), moderate (OR=1.89, 95% CI: 1.26, 2.84), and severe depression (OR=1.74, 95% CI: 1.02, 2.99). Mediation analysis showed that obesity mediated 7.15% and 15.91% of the relationship between depression and infertility for body mass index and waist circumference. Furthermore, depression significantly increased the risk of infertility in both the general obesity (OR=1.81, 95%CI=1.20-2.73, P<0.01) and abdominal obesity populations (OR=1.57, 95%CI=1.08-2.27, P=0.02) populations. In addition, the MR analysis also revealed a significant positive causal relationship between genetically predicted depression and infertility (OR=1.32, 95% CI: 1.03, 1.70).

Conclusion

Depression is associated with an increased risk of infertility, with obesity playing a significant mediating role. This study underscores the importance of incorporating mental health and weight management in infertility treatment strategies.

Cardiovascular Disease, Genetic Susceptibility, and Risk of Psychiatric Disorders and Suicide Attempt: A Community-Based Matched Cohort Study Based on the UK Biobank

BACKGROUND

The associations between cardiovascular disease (CVD) and multiple psychiatric disorders and suicide attempt, and whether different genetic susceptibilities affect such links, have not been investigated clearly.

METHODS AND RESULTS

Based on the UK Biobank, we conducted a matched cohort study involving 63 923 patients who were first hospitalized with a CVD diagnosis between 1997 and 2020, and their 127 845 matched unexposed individuals. Cox models were used to examine the subsequent risk of psychiatric disorders and suicide attempt (ie, anxiety, depression, stress-related disorder, substance misuse, psychotic disorder, and suicide behaviors) following CVD. We further performed stratified analyses by polygenic risk score for each studied psychiatric condition to detect the possible effects of genetic susceptibility on the observed associations. We found an increased risk of any psychiatric disorders and suicide attempt among CVD patients, compared with matched unexposed individuals, particularly within 1 year following the CVD (fully adjusted hazard ratio [HR] within 1 year, 1.83 [95% CI, 1.58-2.12]; HR after 1 year, 1.24 [95% CI, 1.16-1.32]). By subtype, the risk elevations existed for any psychiatric disorders and suicide attempt following most categories of CVDs. Analyses stratified by polygenic risk score revealed little impact of genetic predisposition to studied psychiatric conditions on these observed links.

CONCLUSIONS

Patients hospitalized for CVD were at increased subsequent risk of multiple types of psychiatric disorders and suicide attempt, especially in the first year after hospitalization, irrespective of their genetic susceptibilities to studied psychiatric conditions, and these findings underscore the necessity of developing timely psychological interventions for this vulnerable population.

Association of Frailty With Risk of Incident Hospital-Treated Infections in Middle-Aged and Older Adults: A Large-Scale Prospective Cohort Study

BACKGROUND

Although frailty is associated with a range of adverse health outcomes, its association with the risk of hospital-treated infections is uncertain.

METHODS

A total of 416 220 participants from the UK Biobank were included in this prospective cohort study. Fried phenotype was adopted to evaluate frailty, which included 5 aspects (gait speed, physical activity, grip strength, exhaustion, and weight). More than 800 infectious diseases were identified based on electronic health records. Cox proportional models were used to estimate the associations.

RESULTS

During a median 12.3 years (interquartile range 11.4-13.2) of follow-up (4 747 345 person-years), there occurred 77 988 (18.7%) hospital-treated infections cases. In the fully adjusted model, compared with participants with nonfrail, the hazard ratios (HRs) (95% confidence intervals [CIs]) of those with prefrail and frail for overall hospital-treated infections were 1.22 (1.20, 1.24) and 1.78 (1.72-1.84), respectively. The attributable risk proportion of prefrail and frail were 18.03% and 43.82%. Similarly, compared to those without frailty, the HRs (95% CIs) of those with frailty for bacterial infections were 1.76 (1.70-1.83), for viral infections were 1.62 (1.44-1.82), and for fungal infections were 1.75 (1.47-2.08). No association was found between frailty and parasitic infections (HR: 1.17; 95% CI: 0.62-2.20).

CONCLUSIONS

Frailty was significantly associated with a higher risk of hospital-treated infections, except for parasitic infections. Studies evaluating the effectiveness of implementing frailty assessments are needed to confirm our results.

Impact of healthy lifestyle on the incidence and progression trajectory of mental disorders: A prospective study in the UK Biobank

BACKGROUND

Healthier lifestyle decreased the risk of mental disorders (MDs) such as depression and anxiety. However, research on the effects of a comprehensive healthy lifestyle on their progression is lacking.

METHODS

385,704 individuals without baseline MDs from the UK Biobank cohort were included. A composite healthy lifestyle score was computed by assessing alcohol intake, smoking status, television viewing time, physical activity, sleep duration, fruit and vegetable intake, oily fish intake, red meat intake, and processed meat intake. Follow-up utilized hospital and death register records. Multistate model was used to examine the role of healthy lifestyle on the progression of specific MDs, while a piecewise Cox regression model was utilized to assess the influence of healthy lifestyle across various phases of disease progression.

RESULTS

Higher lifestyle score reduced risks of transitions from baseline to anxiety and depression, as well as from anxiety and depression to comorbidity, with corresponding hazard ratios (HR) and 95 % confidence intervals (CI) of 0.94 (0.93, 0.95), 0.90 (0.89, 0.91), 0.94 (0.91, 0.98), and 0.95 (0.92, 0.98), respectively. Healthier lifestyle decreased the risk of transitioning from anxiety to comorbidity within 2 years post-diagnosis, with HR 0.93 (0.88, 0.98). Higher lifestyle scores at 2-4 years and 4-6 years post-depression onset were associated with reduced risk of comorbidity, with HR 0.93 (0.87, 0.99) and 0.92 (0.86, 0.99), respectively.

LIMITATION

The generalizability to other ethnic groups is limited.

CONCLUSION

This study observed a protective role of holistic healthy lifestyle in the trajectory of MDs and contributed to identifying critical progression windows.

Differences in impact of current and former shift work on cardiovascular risk factors, carotid atherosclerosis, and white matter integrity

Study Objectives

The association of shift work (SW) and disrupted circadian rhythm with markers of large artery atherosclerosis and cerebral small vessel disease is uncertain. We aimed to study the separate association of current and former SW with these markers.

Methods

We included participants from the population-based Hamburg City Health Study. SW was defined by monthly working hours between 06:00 pm and 07:00 am containing night shifts for at least 12 months. Cross-sectional data were obtained from structured questionnaires, laboratory analyses, physical examinations, brain magnetic resonance imaging, and carotid ultrasound. We performed multivariable regression analysis with carotid intima-media thickness (CIMT), and peak-width skeletonized mean diffusivity (PSMD) as dependent variables.

Results

Three hundred and forty-four current, 238 former, and 7162 never-shift workers were included. The median age was 60 years for both current and former shift workers, and total duration of SW was comparable for the two groups. Current shift workers were less frequently female (27.3% vs. 44.5%; p < .001), had more frequent hyperlipidemia (31.5% vs. 22.3%; p = .024), and diabetes (16.2% vs. 3.2%; p < .001). After adjustment for age and sex, reduced quality of sleep (β = 1.61, p = .001) and low education (β = 2.63, p < .001) were associated with current but not former SW. Adjusted for age and sex, the current SW was associated with higher CIMT (β = 0.02, p = .001) and PSMD (β = 9.06e-06, p = .006), whereas former SW was not. Adjusted for risk factors, current SW remained associated with PSMD (β = 9.91e-06, p = .006) but not with CIMT.

Conclusions

Current SW was associated with CIMT and with PSMD, with the latter association remaining after adjustment for risk factors. Former SW showed no associations with CIMT or PSMD. This may indicate that current SW is linked with increased neurovascular risk through disrupted circadian rhythms.

Trial Registration Information

The trial was submitted at http://www.clinicaltrials.gov, under NCT03934957 on January 4, 2019. The first participant was enrolled in February 2016.

The effect of shift work on body mass index: A systematic review and meta-analysis of observational studies

CONTEXT

Shift work involves working outside the standard working hours of 9 am to 5 pm Monday to Friday and may include working evening, night, weekend, or rotating shift patterns. Since shift workers sleep less and their circadian rhythms are disrupted, they are reported to have higher body weight than day workers.

OBJECTIVE

This meta-analysis aims to determine whether shift workers (SW) are more prone to higher body mass index (BMI) than their day workers (DW) counterparts. It also addresses the question of whether the duration of shift work exposure, sex, or occupational type affect BMI value.

METHODS

Four databases that is PubMed, EBSCO Host, Scopus, and Web of Science were searched for reports published up to October 2023.

RESULTS

Sixty-three studies involving a total of 693 449 participants met our inclusion criteria. Meta-analyses showed a significant effect of shift work on BMI value (standard mean difference; SMD: 0.10 kg/m2 [95% confidence interval; 95% CI: 0.07; 0.13; p < .001]) as compared with non-shift counterparts. Subgroup analysis revealed that shift work significantly increased BMI for studies where male working on this job schedule (SMD: 0.10 kg/m2 [95% CI: 0.04; 0.17; p = .0018]) for studies where shift workers worked ≥13 years (calculated as the median of shift work experience; SMD: 0.14 kg/m2 [95% CI: 0.10; 0.18; p < .001]) as well as for studies where industrial (SMD: 0.12 kg/m2 [95% CI: 0.05; 0.19; p = .0012]) and other type of occupations were dominated (0.12 kg/m2 [95% CI: 0.07; 0.16; p < .001]).

CONCLUSIONS

We found that in general working on a shift schedule increases BMI as compared with day workers, especially in case of male employed in this job schedule, for shift workers working for long periods of time (≥13 years), and for shift workers employed in industry and other type of occupations(e.g., airline workers, firefighters, police officers, blue collar, security personnel, bus drivers, garbage collectors, railway workers, postal, oil and gas workers).

Association between Shift Work and Health Outcomes in the General Population in China: A Cross-Sectional Study

Shift work may adversely affect individuals' health, thus, the current study aimed to investigate the association between shift work and health outcomes in the general population. A total of 41,061 participants were included in this online cross-sectional survey, among which 9612 (23.4%) individuals engaged in shift work and 31,449 (76.6%) individuals engaged in non-shift work. Multiple logistic regression analyses were conducted to explore the association between shift work and health outcomes (psychiatric disorders, mental health symptoms, and physical disorders). In addition, associations between the duration (≤1 year, 1-3 years, 3-5 years, 5-10 years, ≥10 years) and frequency of shift work (<1 or ≥1 night/week) and health outcomes were also explored. The results showed that compared to non-shift workers, shift workers had a higher likelihood of any psychiatric disorders (odds ratios [OR] = 1.80, 95% CI = 1.56-2.09, p < 0.001), mental health symptoms (OR = 1.76, 95% CI = 1.68-1.85, p < 0.001), and physical disorders (OR = 1.48, 95% CI = 1.39-1.57, p < 0.001). In addition, inverted U-shaped associations were observed between the duration of shift work and health outcomes. These results indicated that shift work was closely related to potential links with poor health outcomes. The findings highlighted the importance of paying attention to the health conditions of shift workers and the necessity of implementing comprehensive protective measures for shift workers to reduce the impact of shift work.