[Effect of body posture and venous congestion on blood fat picture]

The effects on the concentrations of total cholesterol, high-density lipids (HDL), triglycerides and glycerol of temporary venous occlusion during blood sampling and changing body posture (lying and standing) were measured on 20 healthy male volunteers (mean age 25 [21-27] years) with normal blood-lipid levels. Venous occlusion in the upper arm increased the concentration of lipids in the antecubital vein, by 8% after five min and 37% after 15 min. Initial levels were restored 10 and 15 min after the occlusion. Blood-lipid levels were similarly raised on standing up again. After 5 min they had risen by about 9%, after 15 min by 16%. After renewed recumbency the levels were up from the initial values by 5% after 10 min and by 3% after 15 min (P less than 0.01). The concentration of free glycerol on the whole varied randomly, but there was a statistically significant rise after 10 and 15 min standing. These results indicate that different techniques of blood sampling can influence the lipid concentrations in venous blood.