IMMUNE-SYSTEM DIFFERENCES IN MEN WITH HYPOCHOLESTEROLEMIA OR HYPERCHOLESTEROLEMIA

Substantial epidemiologic evidence indicates that relative hypocholest erolemia in apparently healthy individuals is associated with increase d subsequent mortality from cancer and other nonatherosclerotic causes of death. To test a hypothesis potentially underlying these unexplain ed associations, we evaluated whether individuals with hypo- and hyper cholesterolemia differ in various enumerative and functional indices o f the immune system. Nineteen healthy adult men with a mean age of 46 years and a mean total cholesterol concentration of 151 mg/dl constitu ted a low cholesterol group and were compared with 39 men of a similar age whose total cholesterol averaged 261 mg/dl. Relative to the high cholesterol group, hypocholesterolemic men had significantly fewer cir culating lymphocytes, fewer total T cells, and fewer CD8(+) cells (P's < 0.05). Trends toward fewer CD4(+) cells and less IL-2 release in re sponse to PHA were also noted in the low, compared to the high, choles terol group. The low and high cholesterol groups did not differ in num ber of B lymphocytes, level of PHA-induced proliferation, number of na tural killer (NK) cells, or degree of NK cytotoxicity. These data prov ide preliminary evidence of immune system differences in healthy indiv iduals with hypo- and hypercholesterolemia. (C) 1997 Academic Press.