Oxidative stress is not enhanced in non-malnourished infants with persistent diarrhea.

Increased concentrations of reactive oxygen species (ROS) and depleted antioxidant defences have been implicated in a cycle of infection, malabsorption and malnutrition, leading to persistent diarrhea. In order to determine whether in non-malnourished children oxidative stress predisposes to the development of persistent diarrhea, infants with acute diarrhea (< 7 days) (n = 39) were compared to infants with persistent diarrhea (> 14 days) (n = 38). Lipid peroxidation was assessed by the TBARs assay and expressed as malondialdehyde equivalent content (nmol MDA/ml plasma), and levels of plasma antioxidants vitamin A and vitamin E were determined. In infants with acute and persistent diarrhea nutritional status, as assessed by weight/height and height-for-age, hemoglobin levels, serum albumin and immunoglobulin levels, did not differ between groups. Serum vitamin A and vitamin E levels did not differ in infants with acute or persistent diarrhea. TBARs, expressed as nmol MDA/ml plasma did not differ between infants with acute or persistent diarrhea and furthermore did not differ from levels in a healthy, similar age, control group. Non-malnourished infants with persistent diarrhea do not exhibit plasma antioxidant depletion or enhanced lipid peroxidation. In these infants, oxidative stress, as reflected in plasma, does not play a role in the pathogenesis of persistent diarrhea.