Plasma glutamate, amino acid profiles altered in type 1 diabetes

Among patients with type 1 diabetes (T1D), alterations in plasma glutamate levels and free amino acid profiles are distinct than that in type 2 diabetes (T2D) patients and healthy controls, a recent study has found.

The study included 77 T1D patients (mean age 34.9 years, 67.5 percent women) in whom plasma free amino acid levels were measured using liquid chromatography-mass spectrometry. Parallel groups of 526 healthy controls and 49 T2D comparators were also included in the analysis.

In T1D patients, plasma free amino acid levels showed a more positive-correlation clustering than T2D and healthy control comparators. Meanwhile, T2D patients showed a more diverse correlation pattern among their amino acids.

Amino acid profiles likewise differed between T1D and T2D patients. In particular, glutamate levels were significantly suppressed in T1D, while being strongly elevated in T2D. In turn, the lowered glutamate levels in T1D were found to be correlated with concentrations of glucagon and other similar amino acids.

However, many of these interactions were attenuated in multiple linear regression analysis. In contrast, glutamate remained significantly correlated with a wide array of amino acid and clinical parameters in healthy controls, even after multivariate adjustment.

“We evaluated the plasma free amino acid levels in 77 Japanese patients with T1D in the context of dysregulated glucagon and subsequently showed the characteristic changes in PFAA levels and profiles, especially large decreases in glutamate levels,” the researchers said.

“The findings suggest that T1D shows a comprehensive nutritional disorder that leads to various complications related to amino acid metabolism in addition to glucose metabolism,” they added.