Serum concentrations of lipoproteins, apolipoprotein A-I (Apo A-I), androgens, including biologically active free testosterone (free T), and sex hormone binding globulin (SHBG) and their associations were studied in 3 groups of men of different physical fitness and risk of CHD, consisting of male CHD patients, joggers and healthy controls. Of the 3 study groups, men with angiographically assessed CHD had the lowest HDL-C (P less than 0.002) and highest LDL-C and triglyceride (TG) levels (P = 0.05 and P less than 0.001) and lower 5 alpha-dihydrotestosterone (5 alpha-DHT) levels than joggers (P less than 0.02). Joggers had the highest serum high density lipoprotein cholesterol (HDL-C), Apo A-I and SHBG levels and lowest serum low density lipoprotein cholesterol (LDL-C) compared to the other groups (P less than 0.01). In correlation analysis 5 alpha-DHT was the most significant positive determinant of HDL-C and Apo A-I levels in CHD patients (r = 0.56 and r = 0.55, respectively, P less than 0.05). Moreover, SHBG was significantly positively correlated to both HDL-C and Apo A-I levels in patients, in the whole study group and in healthy men separately (r = 0.37-0.52, P less than 0.01). These significant correlations were also confirmed when age variation and differences in body mass index and smoking were controlled in multivariate analysis and in addition, in multivariate analysis both serum free and total testosterone were inversely related to serum triglyceride (TG) levels.(ABSTRACT TRUNCATED AT 250 WORDS)