Exam stress linked to raised blood sugar levels in non-diabetic medical students

by European Association for the Study of Diabetes

edited by Gaby Clark, reviewed by Robert Egan

Gaby Clark

Scientific Editor

Meet our editorial team
Behind our editorial process

Robert Egan

Senior Editor

Meet our editorial team
Behind our editorial process Editors' notes

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:

fact-checked

proofread

The GIST Add as preferred source

Exam stress is associated with significant increases in blood sugar levels in medical students during exams and in the days leading up to them, according to new research being presented at the annual meeting of the European Association for the Study of Diabetes (EASD) in Milan, Italy (Sept. 28–Oct. 2). The findings highlight the measurable metabolic impact of acute psychological stress.

"Although average daily blood sugar levels did not significantly exceed the upper limit for healthy individuals, and are not dangerous in the short term, they do indicate that exam stress indirectly increases blood sugar levels," said study author Dr. Jan Broz of Charles University and Motol University Hospital in Prague, Czech Republic. "However, because medical students are exposed to examination stress for prolonged, repeated periods of time, often for months, this could well have a negative impact on their metabolic health."

He added, "To manage stress, students are advised to practice stress reduction techniques, ensure adequate sleep, eat balanced meals, get regular physical activity, stay hydrated and avoid excessive caffeine."

Studying medicine is generally considered highly demanding and is associated with substantial psychological stress. Stress is known to raise heart rate and blood pressure. However, there has been little research into whether examinations create enough stress to cause measurable changes in blood glucose levels.

One possible explanation is that increased stress can raise levels of the "stress hormone" cortisol, which may contribute to higher blood glucose levels. Cortisol stimulates the liver to release glucose into the bloodstream, providing the body with a rapid source of energy during stressful situations, such as exams.

To investigate this further, researchers set out to assess whether examination-related stress in medical students was associated with changes in blood glucose levels.

The study included 22 healthy second-year medical students from Prague (13 women and 9 men), with an average age of 21 years and an average body mass index (BMI) of 21.9 kg/m².

The researchers used continuous glucose monitoring (CGM) to measure glucose levels every 15 minutes with a small sensor worn on the back of the arm. Monitoring began seven days before a biochemistry exam and continued until three days after the exam.

On the day of the exam, psychological stress was assessed using the standardized State-Trait Anxiety Inventory (STAI) questionnaire. Participants also reported factors that could influence glucose levels, including physical activity, food intake and sleep.

The highest average daily glucose level was recorded on the day of the examination, at 5.72 mmol/L. This was an increase of 0.37 mmol/L from 5.35 mmol/L on the fourth day before the exam. The level fell 0.30 mmol/L to 5.42 mmol/L the following day.

Similarly, average glucose levels during sleep gradually increased in the days leading up to the exam, from 4.70 mmol/L on the seventh night before the exam to 4.93 mmol/L on the night before the exam.

Glucose levels during different parts of the examination — the written test, break and oral examination — followed the expected pattern of stress, with the highest average level recorded during the written test (6.14 mmol/L).

The analysis also found a significant correlation between stress levels reported in the questionnaire and glucose levels. For instance, students who reported feeling more stressed by the exam (scoring in higher percentiles on the STAI-X1 questionnaire) had a higher average glucose level before exam day, followed by a sharper drop after the exam.

"Persistently or repeatedly 'slightly raised' glucose levels could shift an individual's usual blood glucose range and potentially contribute to the development of type 2 diabetes over time," said study author Natalia Michalcova of Charles University and Motol University Hospital in Prague. "In addition, stress hormones such as catecholamines and cortisol counteract the effects of insulin, and prolonged elevations in these hormones may contribute to insulin resistance through several biological pathways."

She added, "Students experiencing exam stress should be encouraged to look after their health by maintaining healthy eating habits, staying physically active and finding ways to manage stress. Our findings highlight the importance of helping students understand how psychological stress can affect the body, particularly those who may be at greater risk of developing diabetes."

The authors note several limitations, including that the study was observational, involved a small group of medical students and followed participants through a single examination. As a result, it cannot determine the specific causes of the elevated glucose levels. They add that larger studies with longer follow-up are needed to confirm these findings, establish causality, identify risk factors and better understand the potential effects of stress on medical students.

Key medical concepts

blood sugar levelContinuous Glucose MonitoringState-Trait Anxiety Inventory

Clinical categories

EndocrinologyPsychology & Mental healthHealthy livingCommon illnesses & Prevention Provided by European Association for the Study of Diabetes Who's behind this story?

Gaby Clark

MA in English, copy editor since 2021 with experience in higher education and health content. Dedicated to trustworthy science news. Full profile →

Robert Egan

Bachelor's in mathematical biology, Master's in creative writing. Well-traveled with unique perspectives on science and language. Full profile →

Citation: Exam stress linked to raised blood sugar levels in non-diabetic medical students (2026, September 27) retrieved 27 September 2026 from https://medicalxpress.com/news/2026-09-exam-stress-linked-blood-sugar.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.