Selenium and risk factors for cardiovascular disease in New Zealand

Blood selenium (Se) concentrations and glutathione peroxidase (GSHPX) activities were measured in 118 men (39 +/- SD 15 yr) and 112 women (42 +/- 16 yr) randomly selected from the total respondents (1192) to health survey in Milton, a low soil-selenium area in Otago. GSHPx activities were marginally lower for men (11.9 +/- 3.2 units/g Hb) than for women (12.9 +/- 3.8 units/g Hb). Blood, erythrocyte and plasma selenium concentrations were about the same for both sexes and means for all subjects (61 +/- 15; 73 +/- 19; 49 +/- 12 ng Se/ml) were almost identical with a control group of Otago blood donors. No differences in blood levels could be associated with smoking, use of oral contraceptives, arthritis and/or rheumatism, or anti-hypertensive drugs. No relationship was found for the men or women between any of the parameters of selenium status and any of the parameters of risk factors for cardiovascular disease measured in the health survey: age, Quetelet's index, total skinfolds, systolic and diastolic pressure, pulse rate, plasma lipids and lipoprotein lipid concentrations. Moreover no relationship was found for the subgroups (36% group) of men and of women with plasma selenium below 45 ng Se/ml. This study indicates that if selenium is important it does not operate through the risk factors of cardiovascular disease as presently understood.