Determination of total urinary 2,5-hexanedione in the Chinese general population

Determination of the urinary levels of 2.5-hexanedione (2,5-HD) was performed in subjects belonging to the Chinese general population to define the reference value for this metabolite.

Urine samples were collected from 8235 individuals (4216 men and 4019 women) from the healthy general population who had not been occupationally exposed to n-hexane or methyl-n-butyl ketone. The determination was performed by a gas chromatography mass spectrometry method using an ion-trap mass spectrometer.

The result showed that the urinary 2,5-HD median level was 0.159mg/L for the total samples. Males had statistically significant higher excretion of 2,5-HD in urine than females (median 0.171mg/L compared to 0.147mg/L, Z=-8.21, P<0.001). There was a statistically significant difference in urinary 2,5-HD levels among age groups. The excretion of 2,5-HD in urine was related to increasing age (r=-0.160, P<0.05). There was statistically significant difference in urinary 2,5-HD levels among people from difference provinces. The results showed that there was also a statistically significant effect in urinary 2,5-HD levels between current smokers and non-smokers.

Finding a measurable amount of 2,5-HD in urine does not mean that the level of 2,5-HD causes an adverse health effect. Biomonitoring studies on levels of urinary 2,5-HD can provide physicians and public health officials with reference values so that they can determine whether people have been exposed to higher levels of 2,5-HD than are found in the Chinese general population. These data can also provide a foundation for scientists to make a plan for further study.