Detailed Assessment of Night Shift Work Aspects and Potential Mediators of Its Health Effects: The Contribution of Field Studies

Source: van der Grinten, T., van de Langenberg, D., van Kerkhof, L., Harding, B. N., Garde, A. H., Laurell, C., Vermeulen, R., Peters, S., & Vlaanderen, J. (2025). Detailed assessment of night shift work aspects and potential mediators of its health effects: the contribution of field studies. Frontiers in public health, 13, 1578128. https://doi.org/10.3389/fpubh.2025.1578128

Night shift work disrupts circadian rhythms, leading to potential health risks. This review identifies the key factors that mediate these risks and proposes a framework for improving exposure assessment through field studies, leveraging mobile apps, sensors, and biomarkers to enhance understanding and guide intervention strategies.

Understanding the Complexities of Night Shift Work and Its Health Risks

Night shift work is an essential part of various industries, especially healthcare, where continuous patient care is required. However, exposure to night shifts and irregular working hours has been linked to numerous adverse health outcomes, including metabolic syndrome, cancer, cardiovascular diseases, and sleep disturbances.

While epidemiological studies have established these associations, inconsistencies in findings often make it challenging to fully understand the mechanisms at play. The lack of detailed exposure assessments has been identified as a key reason for these inconsistent results. Therefore, high-quality field studies that accurately measure and account for various aspects of night shift work could provide a more comprehensive understanding of the relationship between shift work and health.

In this blog, we explore the various factors that should be assessed in field studies and how new technology like wearable sensors, mobile apps, and biomarkers can enhance data collection. We propose a framework for future research to better understand night shift work, its health impacts, and potential intervention strategies.

Key Aspects of Night Shift Work Exposure

To assess the full scope of night shift work exposure, we highlight four critical areas that should be considered in field studies:

1. Shift Work Schedule-Related Factors

The type, duration, and intensity of shift schedules are fundamental to understanding the impact of night shifts. Detailed logging of work schedules, including deviations, should be incorporated into studies. Mobile apps can offer a user-friendly and efficient way to track and assess shift patterns in real time, ensuring that no relevant data is overlooked.

2. Light Exposure During Night Shifts

Light exposure during night shifts is a known disruptor of the circadian rhythm, making it an essential factor to monitor. Researchers should use light sensors or UV-sensitive badges to measure exposure to artificial light, particularly blue light, which has a stronger influence on circadian disruption. Accurate light exposure data can be captured through smartphone sensors, though their current reliability remains a challenge.

3. Meal Timing and Composition During Night Shifts

The timing and quality of meals during night shifts play a crucial role in circadian misalignment and metabolic health. Studies should evaluate the meal timing, composition, and nutritional value of food consumed during shifts. Tools like the Food-Based Classification of Eating Episodes (FBCE) and 24-hour recall questionnaires can be used to assess dietary intake, while food photography apps may help ensure more accurate data collection.

4. Physical Activity During Night Shifts

The level of physical activity during night shifts can affect both the circadian rhythm and health outcomes. Studies should assess the intensity of physical activity using tools like the International Physical Activity Questionnaire (IPAQ) or actigraphy sensors, which provide objective measurements. This data could also be combined with qualitative reports to understand how different activity levels influence health outcomes in shift workers.

Potential Mediators of Night Shift Work’s Health Effects

While exposure to night shifts is the primary concern, several mediators may influence the health outcomes associated with night shift work. These mediators should be carefully evaluated in future studies:

1. Supplements and Medication Use

Night shift workers often use melatonin, Vitamin D, or other sleep aids to manage circadian disruption. Accurate data on supplement use can be gathered through questionnaires and biospecimens, which can track the metabolism and absorption of these substances.

2. Social Disruption

Night shift work can disrupt social patterns, leading to stress and mental health issues. Assessing social disruption via surveys or mobile apps that track interactions and social activity can help understand how this aspect affects overall well-being.

3. Exposure to Sunlight

Exposure to natural daylight during non-working hours is critical for circadian regulation. Studies should assess sunlight exposure using light sensors or questionnaires to understand how the balance of night light exposure and daylight exposure impacts health.

4. Meal Timing and Dietary Patterns Outside Shifts

Dietary habits outside shift work can also mediate the effects of night shifts on health. Tracking meal timing, dietary composition, and caloric intake using 24-hour recall surveys or smartphone apps can provide insights into how non-shift-related eating patterns contribute to long-term health effects.

5. Physical Activity Outside Night Shifts

Post-shift physical activity may help mitigate some of the adverse effects of night shift work. Assessing exercise routines and physical activity levels outside of work, especially using wearable trackers, can help link activity to overall health outcomes.

6. Sleep Quality

Sleep disturbances are the hallmark of shift work disorder (SWD). Actigraphy sensors can be used to objectively measure sleep quality, while self-reported sleep scales like the Pittsburgh Sleep Quality Index (PSQI) can offer additional insights into sleep disturbances.

7. Substance Use

Night shift workers may have higher rates of substance use (e.g., alcohol, caffeine, or smoking) to cope with fatigue and stress. These behaviors should be assessed through self-reports, questionnaires, or biomarkers to explore their role as mediators of health outcomes.

Effect Modifiers: Occupational Co-Exposures

Night shift workers often face additional occupational hazards that can act as effect modifiers, exacerbating the health risks associated with shift work. These include:

• Chemical exposures: Night shift workers in certain industries may be more exposed to hazardous substances, such as carcinogens, dust, and solvents.

• Psychosocial stressors: Shift work-related stress can increase the risk of mental health disorders and exacerbate existing health conditions.

• Ergonomic factors: Physical demands on night shift workers, such as prolonged standing or heavy lifting, can lead to musculoskeletal disorders.

Assessing these co-exposures requires detailed questionnaires and the use of personal sampling devices (e.g., wearable sensors and biospecimens) to obtain objective data.

The Role of Field Studies in Enhancing Understanding

Field studies that collect real-time data on multiple night shift work-related factors using mobile apps, wearable sensors, and biomarkers can significantly enhance our understanding of how night shift work impacts health. These studies can:

• Generate hypotheses about which factors are most disrupted by night shift work.

• Validate and calibrate exposure assessments in larger cohort studies, improving the accuracy of long-term studies.

• Identify potential causal pathways linking night shift work exposure to chronic health outcomes.

By improving the accuracy and detail of exposure assessments, field studies can provide valuable insights into the mechanisms behind night shift work’s health effects and inform the development of effective interventions.

Conclusion: A Framework for the Future of Night Shift Work Research

Understanding the health effects of night shift work requires a multidimensional approach that considers not only the direct exposure to night shifts but also the mediators, modifiers, and interventions that can influence outcomes. By incorporating advanced tools like wearable sensors, mobile apps, and biomarkers, researchers can collect high-quality data that will deepen our understanding of this complex issue.

This comprehensive approach will not only improve research methodology but also inform workplace policies and health interventions aimed at minimizing the health risks associated with night shift work. As we look toward the future, field studies will play a crucial role in enhancing our knowledge and guiding the development of more effective, targeted solutions for night shift workers.

Author: R.E. Hengsterman, MSN, MA, M.E., RN

Registered nurse, night-shift administrator, and author of The Shift Worker’s Paradox

Nursewhowrites.com

For educational purposes only. Not medical advice.