Prospective comparison of indirect methods for detecting lactase deficiency

Area of Science:

• Gastroenterology
• Clinical Diagnostics
• Biochemistry

Background:

• Lactase deficiency affects a significant portion of the global population.
• Accurate and convenient diagnostic methods are crucial for identifying lactase deficiency.
• Previous methods for detecting lactase deficiency have limitations in sensitivity, specificity, or convenience.

Purpose of the Study:

• To prospectively compare the sensitivity, specificity, and convenience of four indirect methods for detecting lactase deficiency.
• To identify the most suitable method for population screening of lactase deficiency.

Main Methods:

• Prospective study involving 50 subjects (25 with biopsy-proved lactase deficiency, 25 with normal lactase activity).
• Four indirect diagnostic methods were evaluated after lactose ingestion.
• Measurements included breath hydrogen, breath 14CO2, plasma glucose, and plasma galactose levels.

Main Results:

• Breath hydrogen levels were abnormally elevated in all 25 lactase-deficient subjects.
• Breath 14CO2 and plasma glucose tests showed abnormalities in a majority of deficient subjects.
• Plasma galactose levels were abnormal in most deficient subjects when tested with lactose and ethanol.
• Breath hydrogen testing demonstrated excellent sensitivity and specificity without requiring isotopes or ethanol.

Conclusions:

• Breath hydrogen measurement is a highly sensitive and specific non-invasive test for lactase deficiency.
• This method is not influenced by gastric emptying or metabolic factors.
• Breath hydrogen testing is considered the most suitable method for population screening for lactase deficiency.