Although elevated cholesterol and triglyceride levels are often seen in non-fasting blood samples, this may reflect the mobilization of these substrates for energy metabolism. When the dietary supply of glucose does not satisfy the metabolic demands, glucose is synthesized by such gluconeogenetic substrates as glycerol, released from triglyceride stores of adipose tissue, and amino acids derived from muscle protein. 12 Taking action Biochemical quantification of lactase activity in the gut mucosa is the single most reliable method to verify lactose intolerance. This method requires tissue biopsy, however, which is not routinely used in children and infants. 13 Measuring hydrogen in expired breath gases after a lactose challenge test is also widely used.
Results correlate well with intestinal lactase activity.
The most inexpensive and simplest method to determine lactose intolerance is to watch for symptoms after a patient ingests milk. 17 Lactose tolerance can be spontaneously restored if the patient has no latent genetic predisposition to HLD-A and if damage to the mucosa resolves. This can be determined by a subsequent lactose challenge test. Nelson Textbook of Pediatrics. Boeliner SW, Beard AG, Panos TC, et al.