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.