OBJECTIVE: To assess the 24 h profile of androgenemia related to the androgens of both the ovarian and adrenal origin in obese women with menstrual disturbances. METHODS: The association of body mass and body fat distribution with circadian variations of selected androgens of ovarian and adrenal origin was examined in 16 obese women with menstrual disturbances (BMI between 38 and 51 kg/m2; WHR between 0.80 and 0.99) and in 16 healthy volunteers with normal body weight (BMI between 21 and 24.6 kg/m2; WHR between 0.73 and 0.76). The age range of all subjects was 29 to 40 (mean: 36.9+/-3.2 years). RESULTS: lts. Both the patients and control subjects showed a significant 24 h rhythm of androstenedione (A) and free testosterone (FT), while the circadian oscillations of dehydroepiandrosterone sulphate (DHEAS) did not differ significantly. In all obese women mean 24 h A, DHEAS and FT levels were significantly higher than those in controls. Moreover, the disturbances of DHEAS and FT secretion in the form of acrophase shift (for DHEAS from 7.37 to 3.45 h and for FT from 6.04 to 3.31 h) and the elevation of their 24 h amplitude values were observed. All obese women showed higher values of FT/A and FT/DHEAS indexes in selected clock time of day/night cycle (except those at 8.00 h for FT/A and at 5.00 h for FT/DHEAS) when compared to control group. A positive correlation was noted in all women studied between the values of BMI index, WHR ratio and mean 24 h level of androgens studied as well as FT/A and FT/ DHEAS indexes. A weaker correlation was found between body mass and body fat distribution on the one hand and fasting level of hormones studied on the other. Higher correlation between the values of WHR ratio and mean 24 h FT levels as well as FT/DHEAS indexes were obtained in obese women when compared to those of healthy subjects. CONCLUSIONS: Our findings suggest that, when assessing the androgen disturbances in obese patients, it is more useful to determine their circadian pattern than the basal level. The most reliable indicators of hyperandrogenism in obese women are: the 24 h concentration profile of FT and the value of FT/DHEAS index, not only during fasting but also after a meal at various time intervals. Circadian FT concentration and FT/DHEAS index values are essential indicators for visceral distribution of adipose tissue.