Urinary 5-hydroxytryptophol: a possible marker of recent alcohol consumption

Area of Science:

• Biochemistry
• Toxicology
• Analytical Chemistry

Background:

• Urinary 5-hydroxytryptophol (5-HTOL) is under investigation as a biomarker for recent alcohol consumption.
• The 5-HTOL/5-hydroxyindole-3-acetic acid (5-HIAA) molar ratio is employed to correct for urinary dilution.
• This ratio demonstrates individual stability over time in abstinent individuals.

Purpose of the Study:

• To evaluate the reliability and sensitivity of the urinary 5-HTOL/5-HIAA ratio as a marker for recent alcohol consumption.
• To establish a threshold value for the 5-HTOL/5-HIAA ratio indicative of alcohol intake.

Main Methods:

• Monitoring the 5-HTOL/5-HIAA ratio in abstinent individuals over one month.
• Analyzing the 5-HTOL/5-HIAA ratio in healthy volunteers 12 hours post-alcohol consumption.
• Tracking the 5-HTOL/5-HIAA ratio in regular alcohol consumers over three months of drinking.

Main Results:

• The mean 5-HTOL/5-HIAA ratio in abstainers was 7.6, with 97% of values between 4 and 17 (none exceeding 20).
• Alcohol consumption led to a dose-dependent and significant elevation in the 5-HTOL/5-HIAA ratio.
• Regular drinkers showed elevated ratios in 60% of samples during a 3-month drinking period.

Conclusions:

• The urinary 5-HTOL/5-HIAA ratio is a sensitive and reliable biomarker for recent alcohol consumption.
• A proposed threshold of >20 (pmoles 5-HTOL/nmoles 5-HIAA) effectively identifies recent alcohol intake with a low false-positive rate (<0.001).