A key finding about molecular behaviour in specific cells by a team of researchers at University of Otago, New Zealand is holding out promise for doctors examining diabetics to know early enough which patients are at risk of developing heart disease, says Rajesh Katare, Associate Professor of Physiology at one of the oldest institutions in Dunedin.
The team led by Dr. Katare, which used a mouse model to examine the molecular mechanisms involved in the development of cardiovascular complications in diabetes, found that an uptick in cellular change in specific microRNAs (small molecules) was responsible for causing heart disease, a finding which was also replicated in experiments with human heart tissue and found its way into several reputed journals, including the International Journal of Cardiology and Cardiovascular Research .
“The conclusion so far of this long-term study is that we could use microRNAs as a diagnostic bio-marker for predicting the risk of heart disease in diabetic patients,” said Dr. Katare, who was here to deliver the keynote address at JIPMER’s Karaikal campus.
Dr. Katare explains that from an array of 26 microRNAs that the study chose from, scrutiny was restricted to five, which represented about 80 per cent of miRNAs in the heart. Two miRNAs played positive roles, while three potentially killed off heart cells.
Why the finding is significant is that while cardiovascular complication is a well establish risk factor for type 2 diabetes, the advancement of heart disease was a painless process in diabetics. The American Heart Association estimates that cardiovascular complications resulted in the death of at least 60 % of people with diabetes in the U.S.
“If we could analyse these micro RNAs through a simple blood test, it could be possible to identify patients who are most at risk for developing heart disease well before symptoms show up, and save several lives,” Dr. Katare said.
The biggest benefit, perhaps, of these findings is not only in that it helps early detection of the usually masked heart deterioration in diabetics but also in extending a diagnostic solution that is as simple as a blood sample analysis.
While the findings dramatically improve understanding about why people with diabetes are prone to heart disease, the medical interventions available to prevent molecular changes from producing cardiovascular complications is limited and unproven yet. “What we can advocate on diagnosing a diabetic to be at risk of developing heart disease is to prescribe dietary modification and exercise to either ward off the risk or substantially delay the onset,” Dr. Katare said.
On whether researchers engaged with this long-term study, which is now into its sixth year, were able to establish a timeline for the critical change in microRNAs and development of heart disease, Dr. Katare said that the correlation was not as straightforward in humans as it was in mice. The study has also not established any link between how long a patient was diabetic and the change in microRNAs and onset of heart disease.
“However, what we can say is that even in patients who have kept their diabetes in good control, changes in microRNAs that lead to heart disease could happen anywhere between six and ten years”, he said.
“We are now looking to develop a bio-assay that could be a standard for analysing the microRNAs from a routine blood sample,” Dr. Katare said.
