Saliva Test Could Improve Diabetes Control and Treatment

People with type 1 diabetes do not produce enough insulin. The hormone insulin is required for the body to use sugar for energy, so lack of insulin causes unused sugar to accumulate in the blood. This excess sugar in turn leads to complications like cardiovascular, kidney, eye and nerve damage.

With no known cure for type 1 diabetes, the key to preventing these complications is careful control of blood sugar levels. This is achieved with insulin injections, balanced with lifestyle factors like diet and exercise, and requires regular blood testing to monitor sugar control. However, this invasive monitoring can be problematic, particularly in children and adolescents.

Scientists at the National and Kapodistrian University of Athens (Athens, Greece) and their colleagues enrolled a total of 36 subjects who were allocated in three groups. Group 1 (G1) consisted of 12 type 1 diabetic patients with poor glycemic control, group 2 (G2) of 12 patients with satisfactory glycemic control while the control group (Ctrl) comprised of 12 healthy subjects sex-and-aged-matched accordingly. HbA1c values ≥7.5% (58 mmol/mol) indicated poor glycemic control for type 1 diabetes.

The team collected unstimulated whole saliva from all participants. For each sample a total protein amount of 50 μg was measured with the Bradford assay. Labeled peptide samples were stored at −20 °C until they were analyzed by high-pH Reversed Phase (RP) Chromatography. High-pH RP C18 fractionation of the iTRAQ-8plex labeled peptides was performed on the Dionex P680 pump equipped with PDA-100 photodiode array detector using the Waters, XBridge C18 column. All Liquid chromatography–mass spectrometry (LC-MS) analysis were performed on the Dionex Ultimate 3000 UHPLC system coupled with the high resolution nano-ESI Orbitrap-Elite mass spectrometer.

The scientists used a highly sensitive technique and identified and quantified more than 2,000 different proteins. They found that young type 1 diabetics with good blood sugar control had similar saliva protein profiles to non-diabetics. In contrast, young people with poorly controlled type 1 diabetes showed a very different saliva protein profile. The differences were in proteins known to have key roles in inflammation, clotting and blood vessel function, processes that are disrupted by high blood sugar and thereby underlie the major long-term complications of diabetes.

The authors concluded that in-depth analysis of data from this population indicated that differentially expressed proteins are related to acute phase response, endothelial dysfunction, inflammatory and coagulation processes in type I diabetes mellitus. The study was originally published on April 18, 2018, in the journal Frontiers in Physiology.

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