[Urinary lactose determination]

Area of Science:

• Biochemistry
• Pediatrics
• Clinical Chemistry

Background:

• Lactose intolerance is a common condition in infants, affecting digestion and nutrient absorption.
• Accurate and accessible diagnostic methods for lactosuria are crucial for timely intervention.
• Current nonchromatographic methods may lack sensitivity for detecting low levels of urinary lactose.

Purpose of the Study:

• To present a modified, nonchromatographic method for quantifying urinary lactose.
• To evaluate the efficacy of this method in detecting lactosuria in infants with diagnosed lactose intolerance.
• To establish the minimal detectable lactose concentration using the modified assay.

Main Methods:

• A modified nonchromatographic technique was developed for urinary lactose measurement.
• The minimal detectable lactose concentration was determined to be 0.5 g/l.
• Eighty-four infants with diagnosed lactose intolerance (breast-fed or formula-fed) and 29 healthy controls were analyzed.

Main Results:

• The modified method detected lactosuria in 27.4% of infants with lactose intolerance.
• The mean urinary lactose level in affected infants was 0.69 +/- 0.02 g/l.
• No lactosuria was detected in the control group of 29 infants without lactose intolerance.

Conclusions:

• The modified nonchromatographic method is effective for detecting urinary lactose in infants.
• This assay demonstrates sensitivity in identifying lactosuria in a significant portion of infants with lactose intolerance.
• The method provides a reliable tool for diagnosing and monitoring lactose intolerance in pediatric populations.