Endocrine Abstracts

Proton nuclear magnetic resonance spectroscopy (¹H-NMR) was applied to investigate metabolic profile of type 2 diabetes mellitus (T2DM) patients and identify possible disorders of T2DM.

We investigate the potential relationship between diabetic retinopathy (DR), diabetic neuropathy (DN), estimated glomerular filtration rate (eGFR), anthropometric indicators (body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR), waist to stature ratio (WSR)), HbA1c (%) levels and urinary metabolites in T2DM patients.

Serial urine samples of 334 healthy subjects and 388 T2DM patients with a history of diabetes <5 years were investigated by ¹H-NMR. The ¹H-NMR spectra have been recorded on a Bruker Avance DRX 400 MHz spectrometer. The results are evaluated in mmol/mol of creatinine.

A significant difference between the urinary excretion of valine (P=0.007), alanine (P<0.0001), γ-aminobuthyrate (P=0.001), betaine (P=0.036), citric acid (P<0.0001), trimethylamine-N-oxide (P<0.0001) and glycine (P<0.0001) at the healthy individuals and T2DM patients was found. The values for 3-hydroxyisolateric acid (P=0.042), citrate (P=0.019) and γ-aminobuthyrate (P=0.037) increase in T2DM patients with retinopathy vs without retinopathy. There was no correlation between DN and urinary metabolite picture in T2DM patients. We found significant correlation between eGFR and dimethylamine (r=0.194, P=0.031), gamma-aminobuthyrate (r=0.239, P=0.049), acetate (r=0.29, P=0.035) and pyruvate (r=0.275, P=0.014) in T2DM patients. Our analysis revealed significant decreased concentrations for citrate (P=0.005), dimethylamine (P=0.013) and glycine (P=0.009) in T2DM patients with the increase of BMI. WC were positively correlated with gamma-aminobuthyrate (r=0.42, P=0.01) and dimethylamine (r=0.39, P=0.03) and, no correlation were observed between WHR, WSR and urinary metabolites in T2DM patients. Alanine (P=0.003), lactate (P=0.015) and 3-hydroxyisovaleric acid (P=0.006) increased with the increase of HbA1c levels.

Type 2 DM urinary metabolites are interesting in various aspects, such as providing clues for the mechanisms of the disease or potential early markers in diabetes.