Results of the ACTH stimulation test in hirsute women

OBJECTIVE: To determine the incidence of late-onset congenital adrenal hype rplasia (LOCAH) due to 21-hydroxylase deficiency among hirsute women and to evaluate the results of the ACTH stimulation test with the clinical charac teristics. STUDY DESIGN: Prospective, controlled study. One hundred women with hirsuti sm and 14 normally cycling women without hirsutism were included in this st udy at the Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, Cerrahpasa School of Medicine, Istanbul University. After basal serum progesterone (P) and 17 hydroxyprogesterone (17OHP) levels were determined, an ACTH stimulation test was performed on cycle day 3-5. The s ame parameters were checked 30 minutes later. We estimated the 21 hydroxyla se activity by calculating the change in 17OHP (17OHP 30-0) and the summed rate of the change in P and 17OHP ([P30-0]+ [17OHP30-0]/30 minutes). The 95 th percentile for these estimates in normal women were calculated, and valu es above three times the 95th percentile were considered to distinguish wom en with LOCAH due to 21-hydroxylase deficiency. RESULTS: The 95th percentile for 17OHP 30-0 and (P30-0)+ (17OHP30-0)/30 min utes in normal women was 1.6 and 8.9 ng/dL/min, respectively. Regarding 17O HP 30-0 values, three women with hirsutism had levels above three times the 95th percentile of these estimates, and 28 women had estimates of more tha n the 95th percentile but less than threefold. Seventeen of 28 women had ol igomenorrhea, and all had severe hirsutism. The women with severe hirsutism and oligomenorrhea had significantly higher ACTH-stimulated serum 17OHP le vels and values for 17OHP 30-0 and (P30-0 + (17OHP30-0)/30 min) than did no rmally cycling women. CONCLUSION: The incidence of LOCAH due to 21-hydroxylase deficiency and mil d 21-hydroxylase deficiency is 3% and 28%, respectively, in women with hirs utism. Clinical characteristics are not helpful in determining 21-hydroxyla se deficiency. However, the incidence of 21-hydroxylase deficiency is more common among women with severe hirsutism and oligomenorrhea. The change in serum 17OHP 30-0 seems to be greater than the summed rate of change in seru m 17OHP and P in the detection of 21-hydroxylase enzyme deficiency.