Saliva Test Could Identify People Genetically Susceptible to Type 2 Diabetes

As diabetes becomes more prevalent, early detection and prevention are crucial. However, diagnosing the disease early can be difficult. One area that has been questioned is the role of salivary amylase, an enzyme that breaks down starch into sugars. More copies of the AMY1 gene, which expresses salivary amylase, may result in more enzyme production. The relationship between AMY1 gene copy number and diabetes risk is not fully understood, and there is a need for further exploration. Now, new research suggests that higher AMY1 gene copies may have a protective effect against Type 2 diabetes, though more long-term studies are needed to confirm this. If researchers ultimately establish a clear association between AMY1 copy number and diabetes, it could pave the way for genetically testing people at birth to predict their susceptibility to the disease.

A study by researchers at Cornell University (Ithaca, NY, USA) aimed to clarify the connection between the AMY1 gene copy number and diabetes risk. The researchers investigated the role of AMY1 gene copy number in the activity of salivary amylase and its potential link to Type 2 diabetes. The team conducted measurements of amylase activity in participants during early morning and evening, discovering significant differences between the two times. The findings highlighted a diurnal effect, meaning that amylase activity fluctuates throughout the day, regardless of AMY1 gene copy number. The researchers speculated that those with higher AMY1 copy numbers might experience an early insulin response when starches are broken down, offering a possible protective effect against Type 2 diabetes.

The study, published in PLOS One, confirmed that individuals with Type 2 diabetes or prediabetes exhibited higher salivary amylase activity with each additional AMY1 gene copy. This was even true among participants with the same number of AMY1 gene copies, suggesting that amylase activity could be a contributing factor to the disease. The researchers suspect that those with lower AMY1 copy numbers may be at higher risk for Type 2 diabetes, depending on their starch consumption. However, further research is required to explore diet control, long-term follow-up, and a large number of participants to verify these findings and their clinical applications.

“I suspect that people with a lower copy number are at higher risk for Type 2 diabetes,” said Angela Poole, assistant professor of molecular nutrition at Cornell University. "If you knew you had an increased risk of diabetes from day one, it may affect your daily choices, your life choices earlier on where you could prevent it from developing later in life."