Niacin metabolite excretion in alcoholic pellagra and AIDS patients with and without diarrhea

Objective Malnourished patients with the acquired immunodeficiency syndrome (AIDS) can develop pellagra-like manifestations such as dermatitis, diarrhea, and dementia; therefore, we tested the hypothesis that patients with AIDS and diarrhea would have niacin depletion. This study compared 24-h urine excretion of N1-methyl-nicotinamide (N1MN) among patients with pellagra and patients with AIDS who did and did not have diarrhea. Methods Three groups were studied: G1 (patients with AIDS and diarrhea, n = 5); G2 (patients with AIDS and no diarrhea, n = 7), and G3 (patients with alcoholic pellagra and without the human immunodeficiency virus, n = 8). Diarrhea was defined as the production of at least three liquid stools per day over 3 to 5 d. Studies included mucosal intestinal biopsy, malabsorption tests, detection of parasites in stool, and serum albumin measurements. Semiquantitative food-frequency questionnaire, anthropometry, and daily urinary N1MN excretion were also determined. Groups were matched in relation to age, sex, presence of parasites in stool, and intestinal absorption results. Results G1 had normal intestinal examination by light microscopy and no parasites in stools. G2 group showed lower levels of serum albumin (2.6 ± 0.3 g/dL) when compared with G1 (3.4 ± 0.3 g/dL) and G3 (3.1 ± 0.7 g/dL). Except for patients with pellagra, groups met their energy requirements. Patients in G3 (0.013, 0.01–0.081 mg/dL) and G1 (0.062, 0.001–0.33 mg/dL) excreted smaller amounts of N1MN in urine than did those in G2 (0.63, 0.02–2.9 mg/dL). Conclusions Patients with AIDS and diarrhea excreted less N1MN in urine than did those without diarrhea. These patients may have an impaired niacin nutritional status, possibly associated with increased metabolic needs.