Historically, snus use in Sweden was very stable, primarily used by about 20% of men and only 4-5% of women. However, the recent introduction of "white snus" (nicotine pouches) has dramatically changed this landscape. Today, women are using snus at nearly the same rate as men, with the sharpest increase seen among young people.

Globally, snus is gaining massive popularity and is heavily marketed by major tobacco companies as a safe alternative to smoking cigarettes. But is it really safe?

Current research shows a mixed picture. Some studies suggest that snus users have stiffer arteries and face a higher risk of death if they suffer a heart attack or stroke. In fact, quitting snus after a heart attack can cut the risk of mortality in half. Conversely, other studies have found no clear link between snus and heart disease. Because of these scattered and confusing results, more comprehensive research is urgently needed.

What is the study trying to find out? The primary goal of this research is to see if using snus-completely independent of smoking cigarettes-is linked to negative health outcomes. The researchers have a strong hypothesis: they believe snus use may be associated with increased artery damage, higher blood pressure, poorer metabolic health, and higher stress levels.

Specifically, the study will investigate if snus use is connected to:

Heart and Blood Vessel Health: Is snus linked to a higher buildup of plaque in the coronary arteries (atherosclerosis), which can lead to heart attacks?

Metabolic Health: Does snus negatively affect cardiometabolic markers, such as cholesterol levels, blood sugar, body weight, waist circumference, and blood pressure?

Mental Well-being: Is there a connection between snus use and psychological distress, poor sleep, high stress levels, or increased sick leave?

How will the study be conducted?

To get the most accurate answers, the researchers are using data from SCAPIS (the Swedish Cardiopulmonary Bioimage Study), a massive, high-quality health study.

Following People Over Time: The researchers will look at data from two different time points: "SCAPIS 1" (the baseline) and "SCAPIS 2" (the follow-up). This allows them not only to take a snapshot of people's health but also to track how their health changes over time.

Comparing Different Groups: The study will compare people who have never used snus, former users, and current users. It will also look at how much snus people use, how long they have used it, and whether they use traditional tobacco snus or the newer white nicotine pouches.

Advanced Medical Testing: The study relies on thorough medical data, including advanced CT scans of the heart to look for plaque, detailed blood tests for cholesterol and inflammation, and comprehensive questionnaires regarding mental health and stress.

Importantly, the researchers will use advanced statistics to ensure that other lifestyle factors-like diet, exercise, alcohol use, and a history of smoking-do not skew the results. This ensures they are isolating the specific effects of snus.

In Sweden, the number of snus users has remained very stable for many years, with roughly 20 percent of men and approximately 4-5 percent of women classified as users. However, since the introduction of "white snus," usage has increased explosively among women, who now use snus at nearly the same rate as men. Once again, the youngest age groups account for this increase.

Snus use has also gained increasing international popularity. In the US, where Swedish-style portion snus was legalized in 2011, and snus is intensively marketed as an alternative to smoking.

Snus has long been considered a relatively risk-free alternative to tobacco smoking. However, snus users experience increased mortality associated with myocardial infarction and stroke, and studies have shown that mortality in patients with a previous myocardial infarction is halved among those who quit using snus after the infarction compared to those who continue. In experimental studies, investigators demonstrated that snus users who have used snus for more than 15 years exhibit increased arterial stiffness and respond more poorly to nitroglycerin. Other studies, however, have not demonstrated any association between snus use and coronary artery disease. These divergent results indicate that further research is needed to determine whether a genuine link exists between snus use and cardiovascular disease.

The objective is to investigate whether snus use is associated with: An increased degree of atherosclerosis and plaque formation on coronary computed tomography angiography (CCTA/CAC). Elevated cardiometabolic markers associated with an increased risk of cardiovascular diseases (NT-ProBNP, troponins, lipids, glucose, blood pressure, ankle pressure, waist circumference, weight, OGTT) Mental illness, stress, and sick leave.

Additionally, the objective is to explore how changes in snus use between SCAPIS 1 and 2 affect the progression of these factors.

Hypothesis: Snus use, independent of smoking, is associated with increased atherosclerosis and its complications, higher blood pressure, a poorer metabolic profile, and increased stress burden.

Data Material and Study Design:

Data Source: SCAPIS 1 (baseline) and SCAPIS 2 (follow-up).

Design:

Cross-sectional analysis (SCAPIS 1):

Exposure: snus; Outcome: CCTA/CAC, cardiometabolic markers, and mental illness.

Longitudinal analysis (SCAPIS 1→2):

Exposure: change in snus use; Outcome: progression of atherosclerosis, metabolic, and mental health outcomes

Study Sample:

Participants with data on tobacco use, CCTA/CAC, blood pressure, metabolic markers, mental health, and stress. Individuals with known CVD will be excluded.

Cohort Size: Over 30,000 men and women. Locations: Recruited across six Swedish university hospitals: Gothenburg, Malmö/Lund, Linköping, Stockholm, Umeå, and Uppsala.

Inclusion criteria:

• Age 50-64 years at the time of inclusion
• Selection: Randomly selected from the Swedish national population register.

Random selection

Requirements for data access are online: https://www.scapis.org/how-to-apply/requirements/