Markedly increased serum and urinary fructose concentrations in diabetic patients with ketoacidosis or ketosis.

To investigate fructose concentrations in diabetic patients with ketoacidosis or ketosis, serum fructose concentrations and daily urinary fructose excretion were measured in 23 patients with ketoacidosis (n = 16) and ketosis (n = 7) on the first day of admission. Seventeen patients were diagnosed with type 1, one patient with mitochondrial, and 4 patients with atypical diabetes. In 16 of the 23 patients, serum and urinary fructose could be assessed after starting treatments. Mean serum fructose concentration was 71.6 ± 108.1 μmol/l, and mean daily urinary fructose excretion was 352.1 ± 473.7 μmol/day. Serum fructose levels in patients with atypical diabetes were much higher (205.0 ± 213.3 μmol/l) than those in patients with type 1 diabetes (45.1 ± 44.5 μmol/l), while urinary fructose levels in atypical diabetes (249.7 ± 92.4 μmol/day) tended to be lower than those in type 1 diabetes (382.6 ± 533.2 μmol/day). Serum fructose concentrations decreased significantly (P < 0.05) from 88.1 ± 126.3 to 18.0 ± 11.0 μmol/l, and daily urinary fructose excretion also decreased significantly (P < 0.05) from 459.8 ± 530.9 to 75.1 ± 62.0 μmol/day in accordance with glycemic normalization after treatment. Marked and reversible increases in serum and urinary fructose concentrations were observed in diabetics with ketoacidosis and ketosis.