Mean (±SE) baseline and 24-h serum 17-OHP, A4, T, DHEA, E2, and P4 responses to intravenous administration of 1, 10, 25, 100, and 250 µg of hCG in PCOS and normal women. Using linear mixed-effect models analyses, significant increases of 17-OHP, E2, and P4 were observed in both groups. By comparison, incremental A responses were significant only in PCOS women. Between groups, 17-OHP and A responses were significantly greater in PCOS women. Serum T responses were also higher compared to normal women, but the difference did not achieve statistical significance. Significant differences between groups in response to a fixed dose of hCG are indicated by a (P < 0.05), b (P < 0.01), and c (P < 0.001). (Conversion of 17-OHP, A4, T, DHEA, E2, and P4 to SI units by factors of 3.03, 3.49, 3.47, 3.47, 3.67, and 3.18, respectively).