Sex differences in disease anorexia

Sexually differentiated responses occur in molecular, cellular, physiologic, and organismic aspects of immune-system function in relation to acquired and innate immunities. These sex differences apparently include activational effects, which depend on gonadal hormone levels in adults, and lifelong effects, which arise directly from genetic differences or organizational effects of gonadal hormones early in development that lead to lifelong sex differences. Sex differences in immune function also can have great biological significance. Despite this, the mechanisms of these effects rarely have been analyzed extensively. This is especially true of anorexia during illness or disease. Therefore, this review briefly considers 1) the biological mechanisms of sex differences; 2) sex differences in immune function; 3) clinical and experimental data related to sex differences in four diseases or disease models that involve anorexia, Crohn’s inflammatory-bowel disease, cancer, turpentine inflammation, and lipopolysaccharide bacteremia; and 4) sex differences in anorexia after interleukin-1 administration.