Analytical investigation: Assay of d-lactate in diabetic plasma and urine

Objective In this study we developed a 96-micro plate enzymatic assay for d-lactate in plasma and urine. Methods d-lactate was assayed enzymatically with a UV-spectrophotometer in plasma from 38 and in urine from 37 diabetics and from 42 non-diabetic controls. Results The within-run coefficients of variations (CV) were 2.6% for plasma and 5.7% for urine. The between run CVs were 6.8% for plasma and 6.7% for urine. The mean recovery with standard deviation (S.D.) was 107.4 ± 7.3% for plasma and 100.1% ± 6.7% for urine. The plasma d-lactate in diabetics were (mean ± S.D.) 39.6 ± 23.7 μM. We found significant difference between the urinary d-lactate in controls and diabetics (18.2 ± 12.0 vs. 35.9 ± 24.2 μM/mM creatinine, p < 0.0001). Conclusions The assay proved reliable with acceptable precision and recovery. Results suggest that diabetics have elevated urinary and plasma d-lactate as compared to controls.