Research Review: Measuring the expression of Heart enriched microRNAs in Diabetic individuals

I am a second-year Medical Student at the University of Otago who did a summer research project in 2025, looking at different expressions of miRNA between Diabetic and non-diabetic patients' saliva samples. I worked with the Katare lab, which is led by Professor Rajesh Katare and his multidisciplinary research team consisting of a research assistant, postgraduate students and a 5th-year medical student.

The aim of this project was to look at whether tiny biological markers called miRNA found in saliva could help detect early signs of heart disease in people who have diabetes before symptoms appear. This is because diabetic patients are at a higher risk of cardiovascular disease, and current studies show that we can detect cardiovascular disease through blood. This study, therefore, focused on comparing specific miRNAs in saliva samples from diabetic and non-diabetic patients to see if similar results were feasible. Taking blood is invasive and not always culturally appropriate, so this project is investigating whether using saliva as a replacement for detecting cardiovascular disease risk early, as this is less invasive.

In my experiment, I compared small genetic markers found in saliva (miRNA-1 and miRNA-133a) between diabetic and non-diabetic patients to see whether specific small genetic markers linked to heart health were different between the two groups. To ensure that the results are reliable, I compared the markers of interest against a reference marker (miRNA-16) that is stable and commonly used in these experiments to ensure that my experiments were consistent throughout.

From the results, I found that both miRNA-1 and miRNA-133a, both known to be involved with heart function, were lower in diabetic patients compared to non-diabetic patients, with a clear difference.

My results suggest that changes in these small genetic markers in saliva may reflect early changes in heart health in people with diabetes. While this study is small and at an early stage, it supports further research into saliva-based tests as a simple, non-invasive way to help identify heart disease risk earlier in diabetic patients.

A personal highlight of this studentship was gaining hands-on experience in laboratory research. This is because I'm only a second-year university student and don't have much exposure to labs, so getting to learn about new techniques and at the same time getting to use the machines that I never seen was both exciting and a good exposure for my future as a clinical researcher. Two of these procedures are called reverse transcription and polymerase chain reaction, which I have learnt in my university course but have not had the chance to actually carry out experiments, so getting that exposure and applying my knowledge was the highlight of this studentship.