Fig. 2.

Influence of age and gender on circulatory S1P concentrations. S1P was measured in serum ( A ) and plasma ( B ) in a blood donor study group ( N  = 174). Data (mean ± SD) were stratified for age and gender ( F, female =   black bars, M, male =   gray bars ). 20 to 29 years: n  = 15 (F), n  = 16 (M); 30 to 39 years: n  = 15 (F), n  = 20 (M); 40 to 49 years: n  = 10 (F), n  = 22 (M); 50 to 59 years: n  = 18 (F). n  = 31 (M); 60 to 71 years: n  = 10 (F), n  = 17 (M). ^# p  < 0.05 (Kruskal–Wallis test, plasma [all female groups]); ^## p  < 0.01 (Kruskal–Wallis test, serum [all female groups]). No significant differences were detected for male groups. * p  < 0.05, ** p  < 0.01 (Mann–Whitney test). SD, standard deviation.