Abnormal urinary excretion of a quaternary ammonium compound called betaine has been demonstrated in patients with diabetes or metabolic syndrome.
The main predictors of excretion of betaine in cardiovascular patients have been identified and an assessment made of its feasibility as a risk marker of future diabetes development.
Clinical scientists from the University of Bergen (Norway) collected from 2,396 patients urine and blood samples at baseline and in the majority at two visits during follow-up of a median of 39 months. Altogether, 1,772 patients provided urine at all three visits, 348 patients at two visits, and 276 only at baseline. Development of new diabetes during follow-up was assessed among 2,076 patients with no diagnosis of diabetes and either fasting glucose of less than 7.0 mmol/L or non-fasting glucose of less than 11.1 mmol/L at baseline.
Betaine in urine and plasma were measured by liquid-chromatography-tandem mass spectrometry at the laboratory of Bevital AS (Bergen, Norway). The median betaine excretion of 22.2 mmol/mol creatinine was more than three times higher in patients with diabetes compared with patients without diabetes, who showed a small but significant difference in excretion according to low 6.5 mmol/mol creatinine or high serum glucose of 7.1 mmol/mol creatinine. There was a distinct non-linear association between urinary betaine excretion and glycated hemoglobin, with a break point at 6.5%, and glycated hemoglobin was the strongest determinant of betaine excretion in patients with diabetes mellitus.
The authors conclude that diabetes mellitus and long-term glycemic control are the strongest determinants of urinary betaine excretion in a population of patients with mainly stable angina pectoris and without severe renal failure. The long-term test-retest stability is high and betaine excretion is also associated with an increased risk of new diabetes development. The study was published on August 6, 2013, in the journal Public Library of Science ONE.