May 26, 2025, 2:29 pm | Read time: 6 minutes

Those relying on blood values to assess their cardiovascular risk should take note: A new study indicates that even short-term sleep deprivation, the time of day blood is drawn, and physical activity can significantly influence results. These three everyday factors are suspected of distorting key biomarkers for heart health–and potentially leading to misdiagnoses. Particularly concerning: Sleep deprivation alone produced a blood profile associated with a higher risk of heart attack, heart failure, and atrial fibrillation. FITBOOK took a closer look at the study.

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Researchers aimed to uncover distortions in blood values due to sleep deprivation

Luiz Eduardo Mateus Brandão and Lei Zhang are postdoctoral researchers in medical sciences at Uppsala University. With their team, they examined under laboratory conditions how sleep duration, the timing of blood draws, and exercise immediately affect 88 known cardiovascular biomarkers in the blood. The researchers focused particularly on the effects of short-term but repeated sleep deprivation (technical term: short-term sleep restriction) and intense physical training.

Traditional methods for assessing cardiovascular disease risk include factors such as age, cholesterol, or blood pressure–to name just a few. In research, the so-called proteome analysis is used for predicting heart disease risk. This involves examining the entirety of all proteins in a specific tissue or body fluid (e.g., blood plasma) at a given time. With this method, which is not yet standard in clinical practice, hundreds of proteins can be measured simultaneously. This reveals what is actually happening in the body, as proteins are the functional carriers in cells.

Sleep disorders as a risk for severe cardiovascular events–but …

Now comes the caveat: From the perspective of the researchers from Uppsala, it is often overlooked that these markers, which the proteome analysis reveals, can be subject to strong short-term fluctuations. Other studies have shown that sleep deprivation can be a risk factor for heart and blood vessel diseases. Less than five hours per night could be associated with an increased risk of coronary heart disease (CHD).¹

However, it is unknown how sleep deprivation affects these protein markers provided by proteome analysis. The aim of the present study was to uncover clinically relevant distortions to improve the interpretation of blood values in the future.

Also interesting: Intense evening exercise negatively affects sleep after a certain point

Study: 8.5 hours of sleep, sleep deprivation, and 30 min. of intense training

Here’s how the researchers proceeded: They had 16 healthy, normal-weight men sleep normally for three nights (8.5 hours) and not for three nights–in these nights, the men were allowed only 4.25 hours of sleep. Blood samples were taken in the morning and evening. These samples were also taken before and multiple times after a 30-minute high-intensity workout on a stationary bike.

Study results

The researchers examined 88 cardiovascular-related proteins and found the following: Sleep duration, time of day, and exercise triggered significant, sometimes protein-specific changes in the concentration of cardiovascular biomarkers. Important to understand: The study does not directly state that short-term sleep deprivation immediately increases the risk of cardiovascular diseases. Rather, it suggests that sleep deprivation can affect the interpretation of blood values, potentially leading to misdiagnoses.

Short sleep duration produced blood values like those at increased risk for heart failure

Particularly striking: After three nights of sleep restriction, 33 percent of the proteins examined showed significant differences between morning and evening values–much more than with normal sleep (18 percent). The journal “Biomarker Research” published the study results.²

Ultimately, sleep restriction produced a blood profile that matched data from large cohort studies, where these protein patterns were associated with an increased risk of heart failure, coronary heart disease, and atrial fibrillation.

In the following video, FITBOOK expert and cardiologist Dr. Schneeweis explains heart failure:

Different blood values after 30 minutes on the ergometer

High-intensity training also influenced numerous proteins! Immediately after exercise–under normal sleep conditions–the levels of 46 proteins increased significantly. With 4.25 hours of sleep per night, it was only 18. Signaling substances released by the body during physical activity, which have positive effects on health–especially on the cardiovascular system, metabolism, brain, and immune system–increased under both sleep conditions. But mostly more strongly with 8.5 hours per night.

Notably, the effect of exercise on proteins was greater than the influence of the time of day.

Significance of the study findings

The study provides valuable insights for clinical research and practice: Blood values are dynamic–and their significance heavily depends on the context of collection. Those who have slept poorly or exercised shortly before could show blood values at the doctor’s that distort their actual risk–both positively and negatively. Particularly critical: The biomarker pattern produced by sleep deprivation matched the risk profile for various heart diseases known from large studies.

More on the topic

Study Shows Even One Night with Too Little Sleep Can Promote Inflammation

According to a Study From Parkinson’s to Cirrhosis: 172 Diseases Linked to Poor Sleep

Have blood values analyzed rested and without exercise

For patients and doctors, this means: Those having blood values analyzed should be rested–and also avoid exercise beforehand.

Study assessment and possible limitations

Positive aspects of the study include its strictly controlled methodology. However, there are limitations: The participant group was small, with 16 people. Additionally, they were young, male, and healthy. Statements about women, older individuals, the sick, or different chronotypes (sleep types)–from lark to owl–are therefore not directly possible. Longer periods of sleep deprivation were also not examined–even though chronic sleep deprivation is widespread in the population.