Indices of thyroid function and weight loss in human immunodeficiency virus infection and the acquired immunodeficiency syndrome.

Abnormalities of thyroid hormone levels have been reported in the acquired immunodeficiency syndrome (AIDS), but there has been debate as to whether they are appropriate for the clinical status of the patients. Inappropriate maintenance of circulating 3,3',5-triiodothyronine (T3) levels could contribute to weight loss. Although many patients with AIDS have a history of wasting, recent data indicate that prolonged periods of stable weight occur in AIDS and that short-term weight loss is present in a subset of patients with anorexia, many of whom have active secondary infection (AIDS-SI). Therefore we analyzed thyroid hormone levels in a cohort of subjects that have been characterized in terms of recent weight loss and caloric intake. Asymptomatic patients with human immunodeficiency virus infection (HIV+) had short-term stable weights, normal caloric intake, and normal serum T3 levels. In AIDS, average short-term weight was stable, caloric intake was normal, and T3 levels were decreased by 19%. In AIDS-SI, both short-term weight loss and anorexia were significant, and this group showed a 45% decrease in T3 levels. The free T3 (FT3) index was decreased by 30% in AIDS and by 50% in AIDS-SI. Free thyroxine (FT4) levels were decreased while thyroxine-binding globulin (TBG) capacity was increased in HIV+ and AIDS; TBG sialylation was unchanged. Thyrotropin (TSH) levels were slightly increased in AIDS, although levels remained within the normal range. 3,3',5'-triiodothyronine (rT3) levels were decreased in HIV+, AIDS, and AIDS-SI. Thus asymptomatic patients with HIV infection whose weight is stable maintain normal T3 levels.(ABSTRACT TRUNCATED AT 250 WORDS)