Surreal illustration of a nurse struggling to sleep, symbolizing the connection between insomnia and heart health.

Sleepless Nights & Heart Troubles: Is Insomnia or Night Shift Work to Blame?

Elliot Brynn in Health & Wellness December 2025 • 4 min read.

"New research disentangles the complex relationship between sleep disorders, shift work, and cardiovascular disease in nursing professionals, offering critical insights for healthcare workers and employers."

Cardiovascular diseases (CVDs) and poor sleep are known to be linked, but the impact of specific work schedules, like night shifts, has been less clear. Many studies look at CVD and work schedules separately, potentially missing crucial connections. New research investigates the combined effects of insomnia and night work on CVD risk among female nursing professionals, aiming to disentangle these complex relationships.

The study, published in the Brazilian Journal of Medical and Biological Research, involved 1307 female nurses from three public hospitals. Researchers analyzed the association between insomnia and self-reported physician diagnoses of CVD in both day and night workers. A key aspect was considering all sleep episodes, including both nocturnal and diurnal (daytime) sleep, particularly important for night workers who often sleep during the day.

By examining these factors together, the study aimed to determine whether CVD risk is more closely tied to night work itself or to the sleep disturbances that often accompany it. This distinction is critical for developing targeted interventions to protect the health of nursing professionals and potentially other shift workers.

Insomnia, Not Just Night Work, Increases CVD Risk

Surreal illustration of a nurse struggling to sleep, symbolizing the connection between insomnia and heart health.

The study revealed a significant association between insomnia and CVD, regardless of whether participants worked during the day or night. Among day workers, those with insomnia complaints had a 2.79 times greater chance of reporting a CVD diagnosis compared to those without sleep issues. Night workers reporting insomnia during both nocturnal and diurnal sleep periods showed a 3.07 times greater chance of CVD.

These findings suggest that insomnia, rather than night work alone, may be the primary driver of increased CVD risk in this population. This is a crucial distinction because it highlights the importance of addressing sleep quality and duration, regardless of work schedule. The research underscores that the consequences of disturbed sleep are important regardless of when those disturbances occur.

Day Workers: Insomnia complaints increased the odds of CVD by 2.79 times.
Night Workers: Insomnia during both night and day sleep increased the odds of CVD by 3.07 times.
Key takeaway: The likelihood of reporting CVD was similar for both day and night workers experiencing insomnia.

Several factors could explain the link between insomnia and CVD. Sleep deprivation can disrupt the body's natural rhythms, leading to increased blood pressure and heart rate. Inflammation, glucose metabolism disorders, and increased sympathetic nervous system activity are also potential contributing mechanisms. The research adjusted for various confounding variables, including psychosocial factors, further strengthening the argument that insomnia plays a direct role.

Protecting Your Heart: Prioritizing Sleep for All

This study provides valuable insights for nursing professionals and other shift workers concerned about their cardiovascular health. The key takeaway is that addressing insomnia and improving sleep quality should be a priority, regardless of when you work. Simple steps, such as optimizing sleep environment, regular sleeping routine or seeking help from a sleep specialist may help in managing work-related sleep disturbances.

For employers, these findings highlight the need to implement strategies that support the sleep health of their employees, especially those working non-traditional hours. This could include offering sleep health education, providing resources for managing insomnia, and creating work environments that promote rest and recovery.

Ultimately, recognizing sleep disturbance as a public health concern and prioritizing sleep for everyone, not only benefits individual health but also enhances workforce well-being and productivity.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1590/1414-431x20143965, Alternate LINK

Title: Disentangling The Effects Of Insomnia And Night Work On Cardiovascular Diseases: A Study In Nursing Professionals

Subject: Cell Biology

Journal: Brazilian Journal of Medical and Biological Research

Publisher: FapUNIFESP (SciELO)

Authors: A. Silva-Costa, R.H. Griep, L. Rotenberg

Published: 2015-02-01

Everything You Need To Know

What is the main finding regarding Insomnia and Cardiovascular Diseases (CVDs)?

The study found that insomnia, a sleep disorder characterized by difficulty falling or staying asleep, significantly increased the risk of Cardiovascular Diseases (CVDs). This was observed in both Day Workers and Night Workers. For example, Day Workers with Insomnia had a 2.79 times greater chance of reporting a CVD diagnosis. For Night Workers experiencing insomnia, the risk was even higher, with a 3.07 times greater chance of CVD. These findings suggest that Insomnia, not just Night Work, is a primary driver of increased CVD risk in the population studied. The implications are that the quality of sleep is paramount, regardless of work schedule.

What was the study's main objective in relation to Night Work, Insomnia, and Cardiovascular Diseases (CVDs)?

The study investigated the link between Insomnia, Night Shift work, and Cardiovascular Diseases (CVDs). It involved 1307 female nurses from three public hospitals. Researchers analyzed the association between Insomnia and self-reported physician diagnoses of CVD in both Day Workers and Night Workers. The goal was to understand whether CVD risk was more closely tied to Night Work or to the Sleep disturbances that often accompany it, like insomnia. This distinction is critical for developing targeted interventions to protect the health of nursing professionals.

Does Night Work or Insomnia pose a greater risk to cardiovascular health?

The research indicates that the health risks, specifically the risk of Cardiovascular Diseases (CVDs), are more closely tied to Insomnia than to Night Work itself. The study found a significant association between Insomnia and CVD in both Day Workers and Night Workers. This means that the adverse effects on cardiovascular health were similar for both groups when experiencing Insomnia. The key takeaway is that addressing Insomnia and improving sleep quality should be a priority, irrespective of the work schedule.

Does the timing of sleep matter in relation to the findings?

Yes, according to the study, it does matter when you sleep. The research considered all sleep episodes, including both nocturnal and diurnal (daytime) sleep, particularly important for Night Workers who often sleep during the day. The findings emphasize that the timing of sleep, especially for Night Workers, should be considered when addressing Sleep disturbances such as Insomnia.

What are some possible reasons for the connection between Insomnia and Cardiovascular Diseases (CVDs)?

Several factors can explain the link between Insomnia and Cardiovascular Diseases (CVDs). Sleep deprivation, a hallmark of Insomnia, can disrupt the body's natural rhythms, leading to increased blood pressure and heart rate. Other mechanisms include inflammation, glucose metabolism disorders, and increased sympathetic nervous system activity. The research also accounted for other factors, further strengthening the argument that Insomnia plays a direct role. The implications are that managing Insomnia is essential for overall health and reducing the risk of CVD, regardless of the work schedule.